Compatible Development in Single-Family Neighborhoods
Project Goals & Objectives
Strategy Report
January 12, 2009
The Compatible Development in Single-Family Neighborhoods project
was initiated by the Boulder City Council in response to concerns
with potential impacts of additions and new construction in the city’s
established residential neighborhoods.
The project includes four steps. The first step was guided by an initial
problem definition adopted by City Council. Public feedback on the
initial problem definition has helped to clearly define the issues that the
community seeks to address. These issues provide the foundation for
a refined problem statement and recommended strategy to promote
compatible development in single-family neighborhoods.
The second step includes development of the recommended strategy
described in this report. In the third step, specific regulatory tools will be
developed to promote the recommended strategy. Implementation of
the tools will be the final step in the project. Members of the community
will have an opportunity to participate and provide feedback during
each stage.
This report describes the refined problem statement and recommended
strategy. It also provides a summary of existing conditions and the
public process conducted to date. It will be presented to the public
at community workshops in January 2009. Public feedback on the
recommended strategy will lead to further refinement and development
of some or all of the specific tools described in this report.
The recommendations herein are based on a review of the current
zoning code, existing neighborhood characteristics and public
feedback. Community outreach included a series of public workshops
and interest groups as well as a survey mailed to all single-family
property owners within the project area.
Consulting team:
• Winter & Company
• Code Studio
• RRC Associates
• Urban Advisors
Strategy Report Compatible Development in Single-Family Neighborhoods
Project Area
The project area includes single-family detached homes located in the following residential zoning districts:
• Residential Estate (RE)
Parcels in Analysis
• Residential Low Density 1 (RL-1)
• Residential Low Density 2 (RL-2)
N Foothills Hw
• Residential Mixed Density 1 (RMX-1) not including multi-family development Mineral Rd
63rd St
Olde St age Rd
• Residential Rural 1 (RR-1)
• Residential Rural 2 (RR-2)
Properties that are part of Planned Unit Developments (PUDs) are not included in the project area.
Lookout Rd
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Folsom St
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Arapahoe Av
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Fl Baseline Rd
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Cherryvale Rd
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76th St
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South Boulder Rd
Table Mesa Dr
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Lehigh St
Single family detached
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Single Family Detached Properties in Analysis
City Limits
Page 2 January 12, 2009
Compatible Development in Single-Family Neighborhoods Strategy Report
Executive Summary
This report describes existing conditions and public feedback that are
the foundation for a refined problem statement. It then summarizes
potential tools to address the refined problem statement and presents
a recommended strategy to promote compatible development in single-
family neighborhoods.
The recommended strategy was developed by the project consultants
with assistance from city staff. As described in Parts 1 and 2, it draws
upon an analysis of existing conditions and trends, public feedback
received at community workshops, interest group discussions and a
survey sent to all potentially affected property owners. Community feedback received during
the project’s first step provides the
The Refined Problem Statement foundation for the refined problem
statement.
Based on public feedback, City Council’s initial problem definition for
the project was refined to provide a focus of action as an interim step
in the project. As described in Part 2, the following refined problem Building Coverage
statement will guide the remaining steps in the project.
The problem is new single-family construction and additions that are
viewed as being incompatible with adjacent homes and the surrounding
neighborhood in three key respects:
• They are overly large in relation to their lots
• They negatively impact the privacy of neighboring lots
• They cover too much of their lots or result in a loss of mature trees
or vegetation
Part 3 describes a number of potential
The Recommended Strategy tools that were considered including
As described in Part 3, a number of potential tools were evaluated to a building coverage standard.
address the refined problem statement. Based on this evaluation, a
“package” of actions is recommended in Part 4. The basic strategies
for the proposed actions:
• Correlate overall building size to lot size.
• Reduce the perceived mass of a building.
• Preserve open space in the rear of properties.
January 12, 2009 Page 3
Strategy Report Compatible Development in Single-Family Neighborhoods
The proposed actions include a recommended strategy option that
combines Floor Area Ratio (FAR), building coverage and wall sculpting
standards to promote compatible development in single-family
neighborhoods. The recommended strategy option:
• Adjust FAR to fit different zoning districts and lot size categories.
• Articulate building mass to further reduce perceived scale, using
limits on the length and height of side walls at the minimum set-
back line.
• Increase protection for rear yard open space with a maximum
building coverage or minimum rear yard open space percentage.
In addition to the recommended strategy option, two additional strategy
options are presented using differing combinations of tools to address
the same concerns.
Other Recommended Actions
Part 4 describes and illustrates a series
of recommended tools. Several additional actions are recommended including:
• Prepare a voluntary design handbook to help property owners
develop compatible designs.
• Provide for the option of a “neighborhood conservation” overlay
for areas that seek additional design considerations in develop-
ment approvals.
• Place priority on developing neighborhood plans, which would
help to identify distinctive features and special interests in de-
sign.
• If the solar ordinance is updated, include consideration of how it
affects mass and scale.
Next Steps
The recommendations included in this report will be presented and
reviewed with the community at a series of workshops and interest
discussion groups in January 2009. An economics overview will also
be presented.
Following the workshops, City Council and the Planning Board will
discuss the recommendations in a study session and will be asked to
provide direction to staff on how to proceed. Based on their directives,
staff will work with the consultants to prepare formal language for code
amendments.
Page 4 January 12, 2009
Compatible Development in Single-Family Neighborhoods Strategy Report
Report Contents
Part 1: Existing Conditions........................ Page 7
This is a brief summary of existing conditions in the city’s single-
family residential neighborhoods. It includes a summary of existing
neighborhood features, current regulations and development trends.
Existing conditions provide a foundation for the refined problem
statement presented in Part 2.
Part 2: Identifying the Problem................ Page 17
This section describes City Council’s initial problem definition and
summarizes the public outreach effort used to generate community
feedback and refine the list of issues to be considered. It then presents
a refined problem statement focusing on key issues that may be
addressed using the potential tools discussed in Part 3.
Part 3: Potential Tools.............................. Page 27
This section describes a range of tools to address the refined problem
statement. It describes the advantages and potential disadvantages
of each tool, describes related public feedback and indicates whether
the tool is proposed as part of the recommended strategy presented
in Part 4.
Part 4: Recommended Strategy............... Page 53
This section describes a series of strategy options that are
recommended for consideration. Each strategy option includes
a different combination of potential tools. It also describes a
recommended approach for application of the tools as well as
additional recommendations for regulatory streamlining and improved
user-friendliness.
January 12, 2009 Page 5
Strategy Report Compatible Development in Single-Family Neighborhoods
Page 6 January 12, 2009
Part 1: Summary of Existing
Conditions
Existing conditions in the city’s single-family neighborhoods include
both physical and regulatory characteristics as well as current Project Goals & Objectives
development trends. These conditions help shape development and
may influence its perceived compatibility. They provide important
background for the refined problem statement described in Part 2
as well as the potential tools and recommended strategy described
in Parts 3 and 4.
Existing Neighborhood Features
Both qualitative and quantitative features define the city’s existing
single-family neighborhoods. Members of the community identified
a number of mostly qualitative features that help to define their
neighborhoods. Extensive quantitative or statistical information on
existing conditions is archived in the city’s Geographic Information
System (GIS). Additional statistical information is available from the
Boulder County Assessor.
Community Identified Neighborhood Features
As part of the public outreach process, members of the community Existing conditions in Boulder’s di-
helped to identify and describe features of different neighborhoods verse range of single-family neighbor-
and areas throughout the city. These features include quiet streets, a hoods may influence the perceived
sense of stability and a sense of consistency or diversity in the built compatibility of new development.
environment. Commonly identified features are summarized below.
Areas with Different Street Patterns, Topography or Other
Framework Features
Participants identified features such as wide curving streets in Table
Mesa, long north-south blocks with east-west lot orientations in Old
North Boulder, narrow gridded streets with alleys in Mapleton Hill
and consistent lot sizes in University Hill. Participants also noted that
sloping topography and varied lot shapes are features of some parts
of Table Mesa, University Hill, Mapleton Hill and Newlands.
January 12, 2009 Page 7
Part 1: Existing Conditions Strategy Report
Areas with Different Site Features
Participants identified a number of site features that help to define
different neighborhoods such as consistent front yard setbacks in
Newlands and Old North Boulder, alley accessed parking in Mapleton
Hill and Newlands, and front or side yard parking areas in Martin Acres
and Old North Boulder. Participants frequently noted landscape and
open space patterns such as mature trees and landscaping in Mapleton
Hill, large backyards in Old North Boulder, modest landscaping in
Newlands and diverse landscaping in Table Mesa.
Areas with Different Building Features
Participants identified building height, diversity or consistency of
building size and style as well as presence or lack of additions and
new construction as being among the defining building features of
different neighborhoods. Some participants noted defining features
such as diverse, mostly one-story building forms in Old North Boulder,
a high number of additions in Mapleton Hill, unique custom homes in
Table Mesa, uniform architecture of one to one-and-a-half (split-level)
homes in Martin Acres and a mix of old and new houses, remodels
and infill in University Hill.
Statistics on Neighborhood Features
The city’s GIS database and County Assessor’s records may be used
As part of the project’s public outreach to identify existing features such as lot sizes, open space patterns,
process, members of the community building floor areas and setbacks. The table on the next page
helped to identify and describe both summarizes existing lot and building sizes in single-family zoning
qualitative and quantitative features districts. Additional statistics on lot size distribution for each zoning
of different neighborhoods and areas district are included in the Existing Regulations section.
throughout the city.
Workshop participants used maps to identify and list characteristics that
helped to identify different neighborhoods, areas or contexts in the city’s
single-family neighborhoods.
Page 8 January 12, 2009
Strategy Report Part 1: Existing Conditions
Summary of Single-Family Lot and Building Size by Zone District
Zone District: RR-1/RR-2 RE RL-1 RL-2 RMX-1
LOT SIZE 1
Average SF 28,569 16,232 8,953 8,607 4,861
Median SF 25,976 14,375 7,606 8,007 3,962
BUILDING SIZE2
Average SF1 3,933 3,330 2,302 3,108 1,999
Median SF1 3,668 3,104 2,140 2,995 1,775
FLOOR AREA RATIO (FAR)3
Average SF1 0.17 0.24 0.27 0.41 0.50
Median SF1 0.16 0.22 0.25 0.38 0.47
1
Source: City GIS data
2
Source: Boulder County Assessor data
3
The ratio of the floor area of a building to the area of the lot on which the building is situated. Includes principal buildings (including finished
basement areas) and garages as of 12/31/2007. Note that current FAR regulations and those recommended in Part 4 do not include
below ground basements.
January 12, 2009 Page 9
Part 1: Existing Conditions Strategy Report
Existing Regulations
The Boulder Valley Comprehensive Plan establishes general land
use policies for the city and surrounding (primarily rural) land within
the county. The zoning code establishes the basic use and dimen-
sional requirements for additions and new construction in single-
family neighborhoods. Locally designated historic districts such as
Mapleton Hill are also subject to the requirements of the city’s his-
toric preservation ordinance.
Zoning Districts
The zoning districts that apply within the project area are briefly
described below and summarized in the table on page 15. Because
the Compatible Development in Single-Family Neighborhoods proj-
ect has been defined to include only single-family properties, spe-
Current regulations define a three cific land use and density standards are not described.
dimensional building envelope on
each lot. The new construction Residential - Rural 1 (RR-1)
shown above illustrates what could
This zoning district applies primarily to areas that are near the edg-
be built within the building envelope
on two sample lots in the RL-1 zon-
es of the city, including several areas north of Iris Avenue and some
ing district. areas within southeast Boulder. The district’s 30,000 Square Foot
(SF) minimum lot size is intended to help maintain a rural character.
The district’s dimensional standards are similar to the RR-2 district,
but the side setback standard is greater.
Residential - Rural 2 (RR-2)
Like the RR-1 district, this zoning district applies mostly to areas
that are near the edges of the city including some areas north of
Iris Avenue. The district’s 30,000 SF minimum lot size is intended
to help maintain a rural character. The district’s dimensional stan-
dards are similar to the RR-1 district but the side setback standard
is lower.
A variety of existing residential zoning Just over 55% of lots in the RR-1 and RR-2 districts do not meet the
districts apply in some parts of North existing 30,000 SF minimum lot size standard. Nearly 5% of lots are
Boulder. 10,000 SF or less.
Page 10 January 12, 2009
Strategy Report Part 1: Existing Conditions
Residential - Estate (RE)
This zoning district applies to portions of neighborhoods through-
out the city including areas within north Boulder, southeast Boulder
and central Boulder (near Chautauqua). The district’s 15,000 SF
minimum lot size is intended to help maintain a rural character. Its
dimensional standards are similar to the RR-1 district, but has a
reduced side setback standard.
Nearly 60% of lots in the RE district do not meet the existing 15,000
SF minimum lot size standard. About 50% of lots are between
10,000 and 15,000 SF.
Residential - Low 1 (RL-1)
This zoning district applies to a diverse array of neighborhoods
throughout the project area from Newlands to Martin Acres and por-
tions of Table Mesa and Gunbarrel. The district applies to the ma-
jority of single-family homes in the city. It is the only single-family
residential district with an existing floor area ratio (FAR) regulation
(the ratio of the floor area of a building to the area of the lot on which the
building is situated).
The table above provides a snapshot of existing lot sizes in the RL-1 zon-
ing district. Just over 50% of existing lots are between 7,000 and 9,000
SF. Nearly 22% of lots do not meet the existing minimum lot size standard
of 7,000 SF.
January 12, 2009 Page 11
Part 1: Existing Conditions Strategy Report
Residential - Low 2 (RL-2)
This zoning district applies to portions of neighborhoods through-
out the city including several areas north of Iris Avenue and signifi-
cant areas within Table Mesa, Southeast Boulder and Gunbarrel. A
6,000 SF open space requirement per dwelling unit differentiates
RL-2 from other zone districts in the project area.
Many areas that are zoned RL-2 are part of master planned devel-
opments with specific development agreements that often include
restrictive dimensional standards for additions and new construc-
tion. Only existing single-family properties and those RL-2 zoned
areas that are not subject to specific development agreements are
included in the project area for the Compatible Development in Sin-
gle-Family Neighborhoods project.
The table above provides a snapshot of existing lot sizes in the RL-2 zoning
district. About 40% of existing lots are between 7,000 and 9,000 SF while
close to 20% are less than 6,000 SF
Page 12 January 12, 2009
Strategy Report Part 1: Existing Conditions
Residential - Mixed 1 (RMX-1)
This zoning district applies to certain residential areas surrounding
downtown Boulder, including parts of Mapleton Hill and Whittier.
The district recognizes an existing mix of densities including multi-
family development while protecting existing single-family proper-
ties. Some limited commercial uses may be permitted through use
review. The minimum lot size is 6,000 SF.
This project will address only existing single-family properties in the
RMX-1 district.
The table above provides a snapshot of existing lot sizes in the RMX zoning
district. Nearly 68% of existing lots are less than 6,000 SF.
January 12, 2009 Page 13
Part 1: Existing Conditions Strategy Report
Solar Access Regulations
The city’s existing solar access regulations (solar ordinance) limit
the amount of shadow that a building can cast on a neighboring
property. In the RR-1, RR-2, RE and RL-1 districts, the ordinance is
designed to protect solar access principally for south yards, south
walls, and rooftops. In the RL-2 and RMX-1 districts, the ordinance
is designed to protect solar access principally for rooftops.
Northern
property
line
Southern
property
line
The city’s existing solar access regulations (solar ordinance) limit the amount
of shadow that a building can cast on a neighboring property. This may reduce
permitted building height on the northern side of lots.
Page 14 January 12, 2009
Strategy Report Part 1: Existing Conditions
Summary of Existing Dimensional Standards by Zone District
Zone District: RR-1 RR-2 RE RL-1 RL-2 RMX-1
LOT DIMENSIONS
Min. Zone Lot size 30,000 SF 30,000 SF 15,000 SF 7,000 SF - 6,000 SF
OPEN SPACE
Min. Open Space per Dwelling Unit - - - - 6,000 SF 600 SF
INTENSITY
Max. Floor Area Ratio (FAR)2 - - - 0.80 - -
Max. Building Coverage for Accessory Structures1 500 SF 500 SF 500 SF 500 SF 500 SF 500 SF
SETBACKS (Primary Structure)
Min. Front Setback3 25’ 25’ 25’ 25’ 20’ 25’
Min. Side Setback 15’ 10’ 10’ 5’ 5’ 4
5’
Min. Combined Side Setback Total - - - 15’ -
-
Min. Rear Setback5 25’ 25’ 25’ 25’ 20’ 25’
SETBACKS (Accessory Structure)
Min. Front Setback 55’ 55’ 55’ 55’ 55’ 55’
Min. Side Setback 15’ 10’ 10’ 0’ or 3’ 6
0’ or 3’ 6
0’ or 3’6
Min. Rear Setback 0’ or 3’6 0’ or 3’6 0’ or 3’6 0’ or 3’6 0’ or 3’6 0’ or 3’6
Min. Separation Between Primary and Accessory 6’ 6’ 6’ 6’ 6’ 6’
SETBACKS (Parking Areas)
Min. Front Setback for Covered/Uncovered Parking 25’ 25’ 25’ 25’ 20’ 25’
HEIGHT (Primary Structure)
Max. Height7 35’ 35’ 35’ 35’ 35’ 35’
Max. Stories 3 3 3 3 NA 3
HEIGHT (Accessory Structure)
Max. Height 20’ 20’ 20’ 20’ 20’ 20’
“-” Indicates no requirement or that a requirement is not applicable
1
For accessory structures located within the minimum rear setback for the primary structure. Exceptions may be permitted in historic districts.
Maximum building coverage for accessory structures on any part of the lot may not exceed the building coverage of the primary structure.
2
The ratio of the floor area of a building to the area of the lot on which the building is situated. FAR includes basements where more than
50% of the perimeter walls are greater than 2’ above adjacent grade. If less than 50% of the perimeter walls are greater than 2’ above
grade, 50% of basement floor area is counted towards FAR. If all perimeter walls are 2’ or less above grade, no basement floor area is
counted towards FAR.
3
May be reduced if more than 50% of existing structures on the block/street face do not meet the required front setback.
4
Or 1’ per 2’ in building height, whichever is more restrictive.
5
Where a rear yard is adjacent to a street, the minimum rear setback is equal to the minimum front setback.
6
May be reduced to 0’ with common maintenance agreement. Additional standards apply to zero lot line development.
7
The vertical distance from the lowest point within twenty-five feet of the tallest side of the structure to the uppermost point of the roof. The
lowest point shall be calculated using the natural grade. The tallest side shall be that side whose lowest exposed exterior point is lower in
elevation than the lowest exposed exterior point of any other side of the building. As measured from the top of the roof to the lowest point
on the natural grade within 25’ of the lowest exposed point on the building. Note that height standards vary for non-standard lots.
January 12, 2009 Page 15
Part 1: Existing Conditions Strategy Report
Current Trends
After years of relative stability, many established residential neigh-
borhoods across the country have been experiencing significant
changes. Within the last fifteen years, residents began to notice
changes in the character of their neighborhoods. In some cases,
these changes were seen as exciting opportunities. In other cases,
residents worried that inappropriate changes could ruin the charac-
ter of their neighborhood.
Changes such as increased house size and height of additions and
new construction in established residential neighborhoods reflect
current market conditions in which established neighborhoods are
becoming more desirable places to live. Many buyers are seeking to
maximize the square footage of their homes to justify high purchase
prices and add amenities found in new construction. The resulting
wave of infill housing, home expansion and renovation is contribut-
ing to a shift in the character of some neighborhoods.
Cities such as Boulder have experienced rising demand for hous-
ing and an increased pace of change. The pressure for change has
been particularly acute in neighborhoods near existing amenities
such as downtown or the foothills. A review of building permit activ-
ity indicates a trend towards higher building square footages and
floor area ratios in most zone districts within the project area.
Although Boulder’s market remains strong by comparison with the
national residential real estate market, current economic conditions
may slow the trend towards larger homes in established residen-
tial neighborhoods. Once the real estate market begins to improve,
however, the pace of change is likely to increase once again.
New construction in many of Boulder’s
single-family residential neighbor-
hoods is often larger than surrounding
homes. The two homes illustrated
demonstrate recent trends in a central
Boulder neighborhood. The permitted
three-dimensional building envelope
defined by current regulations in the
RL-1 zoning district is also shown.
Page 16 January 12, 2009
Part 2: Identifying The
Problem
The community has struggled with issues related to the compatibility of
new infill development in single-family neighborhoods for many years.
Previous efforts to address neighborhood compatibility issues in the
city have generated considerable controversy. Although there have
been incremental changes to existing regulations, the community has
not implemented a system to address neighborhood compatibility.
Past efforts to address potential issues have been criticized as too
restrictive or as responding to a problem that does not exist or is
very limited in scope. Prior to moving forward, the city has sought to
clearly define the problem and evaluate the potential impact of any
proposed solutions. City Council adopted an initial problem definition
that was followed by a public outreach effort to generate community
feedback and refine the list of issues to be considered. This provides
the foundation for a refined problem statement focusing on key issues
that will inform a set of specific recommended actions.
Initial City Council Problem Definition
In April 2008, the Boulder City Council adopted the following initial
problem definition to direct the Compatible Development in Single-
Family Neighborhoods project:
“To address the impact on existing established neighborhoods of new
construction and additions that are incompatible in scale and bulk
with the character of the neighborhood. The impacts to be considered A public outreach effort included
include without limitation: consideration of size, green space, massing interactive community workshops
and bulk planes, loss of space between houses, privacy, view sheds, and a survey sent to all single-family
property owners in the project area.
lot coverage, blank walls, setbacks, height and the streetscape and
Public feedback received provides
visual character.” the foundation for a refined problem
statement that will inform a set of
The City Council’s initial problem definition provides an additional recommended actions.
list of specific issues and considerations including:
• Homes that are overly large for their lots and neighborhoods
• Speculative homes that maximize square footage with limited
setbacks
• Loss of green space
• Impacts to the visual character of neighborhoods
• Loss of mature trees, backyards and sunlight
• The loss of older homes representing the community’s heritage
• Effect of the solar ordinance on the shape of buildings
City Council also adopted specific goals and objectives which were
used to evaluate the potential tools described in Part 3 and inform
development of the recommended strategy presented in Part 4.
January 12, 2009 Page 17
Part 2: Identifying the Problem Strategy Report
Feedback Summaries Community Feedback
Complete workshop, interest The first step in the Compatible Development in Single-Family
group and survey summaries Neighborhoods project tested and refined the City Council’s problem
are available on the project definition in consultation with members of the community. This public
web site. Go to: outreach effort sought to answer several questions:
www.boulderplandevelop.net • What is the community’s response to the initial City Council
and click on “Hot Topics” problem definition?
• Are there additional issues to be addressed?
• Which issues are most and least important?
• What potential actions should be considered?
• Are there related issues and concerns that need to be acknowl-
edged?
The public outreach effort included five workshops with over 180 total
participants, two interest group sessions with 21 total participants
and a property owner survey with over 3,700 participants. Members
of the community also provided comments through the project web
site. Each of the primary components of the public outreach effort
to date are described below. Key conclusions are reflected in the
refined problem statement.
Community Workshops
The project began with a community kick-off workshop followed by
four neighborhood area workshops. Participants at each workshop
completed a series of interactive exercises. These activities offered
opportunities for individual comments and to work as teams to
discuss important concepts and provide feedback. The information
garnered during the workshops helped inform the contents of both
the community survey and the refined problem statement described
in this report.
A separate Community Workshop Summary document provides
a detailed description of workshop results. Feedback provided by
workshop participants is summarized below.
Agreement with the Initial Problem Definition
Participants in each of the workshops Many participants expressed agreement with the initial problem
completed a series of interactive ex- definition adopted by City Council at the outset of the project.
ercises and presented the results of Participants who did not agree with the problem statement generally
small group discussions. noted that it either failed to mention important issues, that potential
solutions would negatively impact property owners or that there was
not a problem.
Concern with the Potential Impacts of New or Revised Regulations
Many participants expressed concern that the initial problem definition
could lead to new or revised regulations that would be burdensome
to property owners or builders and limit design flexibility.
Page 18 January 12, 2009
Strategy Report Part 2: Identifying the Problem
Concern with How Final Decisions Will Be Made
A number of participants felt that residents should be allowed to
vote to determine whether there was actually a problem or whether
specific regulations should be enacted.
Interest in Addressing Related Community Goals and Issues
A number of participants felt that the project had been defined only
to address cosmetic or aesthetic issues and hoped that broader
issues and concepts could be considered. The concerns that
some participants wished to address included community-wide
economic goals, affordable housing, environmental sustainability
and neighborhood planning.
Concern that the Problem is Isolated to a Few Projects
A number of participants expressed the view that any potential
problems were related to a small number of inappropriate projects and
that far reaching restrictions would be an inappropriate reaction.
Identification of Specific Design Issues
Participants identified a number of specific issues that they felt were
currently problematic or could become problematic with the design
of new construction and additions in single-family neighborhoods.
The most commonly cited issues included:
• Overly long, tall or blank walls near setbacks
• Houses that are, or appear to be, much larger than their neigh-
bors or the surrounding context
• Loss of open space
• Accessory structures that impact alley character or have privacy
and compatibility impacts on neighboring properties
• Loss of mature trees and vegetation
Concern That Existing Regulations May Produce Unintended Workshop participants provided
Consequences or Lead to Undesirable Forms feedback using both an individual
Some participants cited specific issues or concerns with potential worksheet and poster-size group
worksheets.
unintended consequences relating to existing regulations or processes,
such as solar access regulations or the process for calculating height
on sloping lots.
Concern with Changes to the Social Character of Neighborhoods
and the Community
Some participants felt that the social character of their neighborhoods
and, possibly the broader community, is changing in undesirable
ways. In some cases, participants noted design-related issues such
as overly large garage doors or lack of open space that made new
houses less conducive to social interaction.
January 12, 2009 Page 19
Part 2: Identifying the Problem Strategy Report
Interest Groups
The community workshops were followed by two special sessions
that provided a diverse selection of participants with the opportunity
to have a more in-depth discussion of potential issues and solutions.
The groups included members from local organizations, professionals
in the field of single-family development, and neighborhood
representatives.
A separate Interest Group Summary document provides a detailed
description of the two discussion sessions. Overall themes are
summarized below.
Support for Strategies that Recognize Context and Preserve
Flexibility
Many participants noted that “one size does not fit all” and expressed
the need for flexibility in any proposed regulations. Discussion focused
Interest group participants completed
on potential issues with non-standard lots and differing neighborhood
a brief survey prior to the group dis-
cussion.
conditions.
Concern Regarding Large, Long and/or Featureless Walls at or
Near the Side Setback
Participants in both groups indicated that the character of a building’s
side walls could have aesthetic or privacy impacts on neighbors.
Interest in Preserving Mature Vegetation or Landscaping
Some participants were concerned with the loss of mature vegetation
or landscaping that could occur with additions or new construction.
A Desire to Review or Streamline Existing Regulations
Many participants felt that some of the unintended consequences of
existing regulations, including the solar access ordinance and height
measurement system, made them worth reviewing.
Concern that the Project is Responding to a Problem That Does
Not Exist
A number of participants, especially those in the first discussion
group, felt that the project represented a “solution in search of a
problem.”
Concern Regarding the Possibility of New Regulations
While participants expressed concerns about the impacts of
incompatible development in their neighborhoods, many were also
concerned that the project could lead to additional regulations and
bureaucracy.
A Desire to Allow for Increased Density
Several participants spoke of the need to increase population densities
to address sustainability or affordable housing goals. In some cases,
they hoped to see greater flexibility for duplex, multi-family or carriage
house development within primarily single-family neighborhoods.
Page 20 January 12, 2009
Strategy Report Part 2: Identifying the Problem
Community Survey
To facilitate a broader range of public feedback, a survey was mailed to
all single-family property owners in the project area. The survey asked
participants to provide feedback on the City Council’s initial problem
definition and a series of statements reflecting feedback heard during
the community workshops. It included questions regarding potential
actions and tools and presented a series of alternative development
scenarios to generate feedback on compatible development options.
Additional demographic and geographic questions were also included
to help determine how responses varied for different parts of the city
(as shown on the map below) and by age, income, experience and
other characteristics of survey participants.
Of just over 12,000 surveys sent, 33% were returned. A separate report
provides an in-depth summary of survey responses, with a series
of detailed charts and graphs. The summary of survey responses Side wall jog reduces
wall lengths.
below includes only those overall themes that were used to develop
the refined problem statement. The survey included questions to
generate feedback on how different
Agreement with the Initial Problem Definition design variables affect the compat-
About 65% of survey participants expressed agreement with the City ibility of development in single-family
Council’s initial problem definition (20% strongly agreed), 14% did not neighborhoods.
indicate particular agreement or disagreement and 21% disagreed
(9% strongly disagreed). Gunbarrel was the only area where most
participants did not express overall agreement with the initial problem
definition. Agreement was highest in Central Boulder.
US 36
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2. North
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Iris Ave.
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Foothills Pkwy.
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Balsam Ave.
Alpine
3. Central
Boulder Arapahoe Rd.
5. Southeast
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Baseline Rd. Baseline Rd.
The survey asked participants to
King Ave.
US choose one of five areas in Boulder to
4. South 36
indicate where their house is located.
Boulder Participants could also choose one
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of four subareas if their house was
oa
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located in Central Boulder and one of
ay
two subareas if their house was located
in South Boulder.
January 12, 2009 Page 21
Part 2: Identifying the Problem Strategy Report
A Sense That New Construction and Additions Are Not Having
Overall Negative Impact on Neighborhoods
Although survey participants expressed general agreement with the
initial problem definition, only 30% agreed that the character of their
neighborhoods was being negatively impacted by recent construction
(13% strongly agreed) while 15% did not indicate particular agreement
or disagreement and 55% disagreed (26% strongly disagreed).
Participants from Central Boulder were more likely to agree that recent
construction was an issue in their neighborhoods with 52% expressing
Lower proportion of
building size to lot size.
agreement (31% strongly agreed), 11% not indicating particular
agreement or disagreement and 37% expressing disagreement (16%
strongly disagreed).
Support for Requirements that Relate House Size to Lot Size
About 67% of survey participants agreed that requirements should be
set to relate the size of a building to the size of its lot (26% strongly
agreed), 13% did not indicate particular agreement or disagreement
and 21% disagreed (9% strongly disagreed). Gunbarrel was the
only part of the city where most participants did not express overall
agreement. The level of agreement was very similar throughout other
parts of the city.
Higher proportion of Although there was agreement that house size should be related to
building size to lot size. lot size, it is important to note that only 43% of survey participants
agreed that some recent construction in their neighborhoods was too
A majority of survey participants
large (21% strongly agreed) while 13% did not indicate particular
agreed that requirements should be
set to relate the size of a building to agreement or disagreement and 45% disagreed (21% strongly
the size of its lot. disagreed). In addition, 42% of survey participants agreed that bigger
houses could fit in if they are well designed (22% strongly agreed)
while 17% did not indicate particular agreement or disagreement and
20% disagreed (5% strongly disagreed).
Page 22 January 12, 2009
Strategy Report Part 2: Identifying the Problem
Concern With Building Coverage and a Possible Loss of Open
Space or Mature Trees or Vegetation
About 56% of survey participants agreed that a limit on the percentage
of building coverage on a lot should be considered (18% strongly
agreed), 17% did not indicate particular agreement or disagreement
and 21% disagreed (11% strongly disagreed). Agreement was highest
in Central Boulder and North Boulder.
51% of survey participants agreed that the loss of mature vegetation
when new construction occurs is a key issue (16% strongly agreed),
17% did not indicate particular agreement or disagreement and 32%
disagreed (12% “strongly disagreed”). Agreement was highest in
Central Boulder.
Although there was agreement that a limit on the percentage of building
coverage should be considered, it is important to note that only 49%
of survey participants agreed that the loss of green space when new
buildings are constructed is a key issue (18% strongly agreed) while
15% did not indicate particular agreement or disagreement and 37%
disagreed (16% strongly disagreed).
Building Coverage
A majority of survey participants agreed that a limit on the percentage of
building coverage on a lot should be considered.
January 12, 2009 Page 23
Part 2: Identifying the Problem Strategy Report
Concern With Potential Privacy Impacts of New Construction and
Additions and Support for Requirements Related to Side Walls
About 62% of survey participants agreed a large house next door
diminishes privacy in others’ back yards (26% strongly agreed),
12% did not indicate particular agreement or disagreement and 26%
disagreed (9% strongly disagreed). Agreement was highest in Central
Boulder and North Boulder.
Survey participant support for side wall height requirements may be
related to privacy concerns. About 56% of survey participants agreed
that wall height limits should be lower near the side property line
(16% strongly agreed), 19% did not indicate particular agreement
or disagreement and 24% disagreed (10% strongly disagreed).
Agreement was highest in Central Boulder and North Boulder.
Large featureless walls along the side of a building were a less
pronounced concern for survey participants. However, 50% agreed
that they could be an issue (16% strongly agreed), 20% did not
indicate particular agreement or disagreement and 28% disagreed
(10% strongly disagreed).
Support for Making Changes to Existing Regulations
Most survey participants felt that some action should be taken to address
the compatibility of development in single-family neighborhoods or to
streamline existing regulations. Only 12% of survey participants said
that no changes should be made to existing regulations while 59%
said that existing zoning standards should be changed to mitigate
the impact of larger buildings either throughout the city’s single-family
zone districts or only in certain targeted areas.
Many survey participants also supported streamlining existing
regulations (30%), providing additional flexibility for special conditions
(35%) and establishing a review and approval process tailored to
individual neighborhoods (41%).
Side wall height steps
down along side property
line.
A majority of survey participants agreed that wall height limits should be
lower near the side property line.
Page 24 January 12, 2009
Strategy Report Part 2: Identifying the Problem
Refined Problem Statement
City Council’s initial problem definition guided the first step in the
project including extensive public outreach to more clearly define
the issues that the community seeks to address. Based on public
feedback, Council’s problem definition remains valid. However, public
feedback does provide direction for a focus of action as an interim
step. This may be considered as a refinement to Council’s initial
problem definition. The following refined problem statement will guide
the remaining steps in the project:
The problem is new single-family construction and additions that are
viewed as being incompatible with adjacent homes and the surrounding
neighborhood in three key respects:
• They are overly large in relation to their lots Community feedback received during
the project’s first step provides the
• They negatively impact the privacy of neighboring lots
foundation for the refined problem
• They cover too much of their lots or result in a loss of mature trees statement.
or vegetation
January 12, 2009 Page 25
Part 2: Identifying the Problem Strategy Report
The refined problem statement informs an evaluation of the
potential tools described in Part 3 and provides a foundation for the
recommended strategy presented in Part 4.
It will be important to ensure that any revised regulations drafted to
support the problem statement are carefully integrated into existing
regulations. Where feasible, existing regulations should also be
simplified or streamlined so that they are easier to use and do not
create unnecessary barriers for homeowners or for architects and
builders who are engaged in compatible development projects in
single-family neighborhoods.
The problem statement reflects only those issues that have been
Members of the community will review
and comment on the refined prob-
identified with the character of development in single-family
lem statement and recommended neighborhoods. Several related problems and issues identified by
strategy. members of the community are described in Part 4.
Page 26 January 12, 2009
Part 3: Potential Tools
A number of potential tools could be used to address the refined
problem statement. This section of the report describes the range of
potential tools that were considered for inclusion in the recommended
strategy presented in Part 4 and indicates whether each tool is, or is not,
recommended. Three general categories of tools were considered:
1. Planning Tools
These tools include planning documents that provide goals and
objectives for a particular area. They may be used to guide public
improvements or the development of more specific regulatory tools
such as design standards and guidelines.
A range of potential tools were consid-
2. Design Standards ered to address the refined problem
For purposes of this report, a “standard” is a regulation that is statement and promote compatible
prescriptive. It can be measured or it can clearly be determined to development in single-family neigh-
have been met. For example, a minimum side yard setback distance borhoods.
of 5 feet is a measurable, prescriptive standard. A setback of 4 feet
does not comply.
3. Design Guidelines
For purposes of this report, a “guideline” is a qualitative regulation. In
determining compliance with a guideline, some judgment is required. In
addition, a balancing of guidelines may occur. It may not be necessary
to meet all guidelines fully. The manner in which guidelines are applied
may vary. Some guidelines are used in a mandatory review and
compliance process. In that case, approval by a reviewer is necessary
in order to receive a building permit. (The city’s existing Landmarks
review process is an example.) Other guidelines may be applied in a
“advisory” manner, in which a review meeting is required, but compliance
may not be. (The city’s Downtown Design Advisory Board operates in
this manner for some projects.) Still other guidelines are distributed
as an informational tool, to be used voluntarily.
Planning tools generally operate at the neighborhood, or framework,
level. Other tools may operate at one or more of three primary
levels:
1. Neighborhood, or Framework, Level
These address the character of the public realm, such as streets and
sidewalks, as well as broader design variables that are shared among
residents.
2. Site Level
These address the placement of a building on its site, the extent of
paving and green space, including landscaping.
3. Building Level
These address the overall size of a building, as well as the way massing
may be arranged.
January 12, 2009 Page 27
Part 3: Potential Tools Strategy Report
Neighborhood, or Framework, Level Tools
Tools such as long-term neighborhood plans and associated street
standards or lot size standards help preserve and promote an
existing or desired character throughout a neighborhood or group
of neighborhoods. They may determine where different kinds of
housing, parks or neighborhood shops and offices should be located
and provide a blueprint for the character of streets, sidewalks and
public landscaping.
Neighborhood Planning
Some communities use neighborhood plans to guide development
within an established context. Such plans provide a future vision and
can be used to guide the development of specific tools such as design
guidelines to promote goals and objectives at the neighborhood level.
Neighborhood plans could also be used to direct possible future design
review processes and provide a blueprint for streetscape design.
Advantages of neighborhood planning:
The existing North Boulder Subcom-
munity Plan provides neighborhood
• Provides specific policies, goals and objectives for future devel-
planning level policies, goals and opment at the neighborhood level
objectives for neighborhoods north • Provides a fine-tuned level of guidance for public improvements
of Iris Avenue. (parks, paths, streetscape, etc.)
• May guide development of context sensitive tools to promote
desired design and development patterns
Potential disadvantages of neighborhood planning:
• May be costly and time consuming
• May not address current issues in a timely manner
Existing Neighborhood Plans
Neighborhood plans have not been adopted for most parts of the
project area. However, a limited number of existing plans such as the
North Boulder Subcommunity Plan provide neighborhood planning
level policies, goals and objectives for some areas.
The city’s Board of Zoning Adjustment (BOZA) does not currently
consider neighborhood plans when reviewing variance requests.
However, consideration could be given to allowing any such plans
to inform future variance requests.
Community Feedback
Participants in the community workshops, interest groups and
property-owner survey expressed a desire for context-specific
strategies for neighborhood development.
About 58% of survey participants agreed that regulations to address
new single-family construction should vary by neighborhood (14%
strongly agreed), 18% did not indicate particular agreement or
disagreement and 22% disagreed (10% strongly disagreed).
Page 28 January 12, 2009
Strategy Report Part 3: Potential Tools
About 41% of survey participants felt that one of the actions the city
should take was to establish a design review and approval process
that is tailored to individual neighborhoods.
Participants in the community workshops and interest groups also
provided feedback that could relate to neighborhood planning. Some
participants expressed a desire for potential density increases (to
address affordable housing or promote citywide sustainability goals),
improved pedestrian networks or land use changes to allow for
neighborhood centers or corner stores..
Recommendation
Because neighborhood plans would not provide a timely response
to the refined problem statement, they are not included in the
recommendations presented in Part 3. Neighborhood planning efforts
would, however, facilitate consideration of context-specific strategies
for neighborhood development and could help determine if and where
land use and density changes could be appropriate. Therefore, the
city should continue to advance neighborhood planning efforts to
help determine the future vision for single-family neighborhoods
or groups of neighborhoods. Neighborhood plans should address
land use and density, determine appropriate locations for parks and
neighborhood retail or employment centers and guide development
of the public realm including streetscape and pedestrian networks. Tools such as neighborhood plans and
associated street standards can help
Streetscape Design preserve and promote an existing or
The character of a neighborhood is substantially influenced by the desired neighborhood character.
design of the public realm. Standards for street trees, the use of
planting strips along the curb, and the placement and materials of
sidewalks are basic features. Street lights and other utilities also
affect character.
Community Feedback
Some participants in the community workshops expressed a desire
for additional streetscaping in their neighborhoods, particularly
street trees and other landscaping that could reduce mass and scale
impacts. However, the results of the property owner survey appear
to indicate that there is a greater concern with development potential
on adjoining lots than with the effects of mass and scale as viewed
from the street.
Recommendation
Because streetscape standards would not directly address the refined
problem statement, they are not included in the recommendations
presented in Part 4. Streetscape standards can, however, influence the
perception of building mass and scale, where extensive tree canopy
effect buffers views of houses. Therefore, the city should consider
updated streetscape design as part of any future neighborhood
planning efforts.
January 12, 2009 Page 29
Part 3: Potential Tools Strategy Report
Lot Size Standards
Lot size standards determine density and influence the general character
of single-family neighborhoods. They generally set a minimum size for
lots but may also set a maximum lot size. Lots may not be subdivided
if a resulting lot would be smaller than the minimum standard. In
addition, existing lots that are smaller than the minimum standard
may be considered as “non-standard” and require variances to obtain
permits for additions and new construction.
Each of the zoning districts within the project area currently includes
a minimum lot size standard ranging from 6,000 square feet (SF) in
RMX-1 to 30,000 in RR-1 and RR-2.
Community Feedback
Participants in the community workshops, interest groups and property-
owner survey provided feedback on potential density increases and
changes to existing regulations to streamline development approval
on non-standard sized lots.
Recommendation
No changes are recommended to current lot size standards. However,
Part 4 describes strategies to help streamline existing regulations to
more easily permit compatible development on existing lots that do
not conform with minimum lot size standards.
Page 30 January 12, 2009
Strategy Report Part 3: Potential Tools
Site Level Tools
Tools such as lot coverage, building coverage, open space and
landscaping standards help preserve and promote an existing or
desired character within and among individual lots. They may determine
where buildings are located relative to the street and sidewalk and how
much green space is visible from the street or separates structures
from each other.
Lot Coverage Standards
Lot coverage standards may dictate the maximum percentage of a
lot surface that can be covered by built areas such as buildings or
Site level tools help preserve and pro-
paved areas. Often, any impervious surface area (those that shed
mote an existing or desired character
water such as building roofs, patios, driveways and walkways) is
within and among individual lots.
considered as lot coverage
Advantages of lot coverage or standards: Lot Coverage Diagram
• Helps maintain green space
Potential disadvantages of lot coverage standards:
• Could encourage taller structures (to allow for larger driveways
patios, etc.) if not combined with specific height or floor area
ratio standards
• Limits on all hard surfaces would not have as significant an ef-
fect on building form as building coverage standards
Buildings
Existing Standards
A maximum lot coverage standard is not currently used within the
project area. However, the minimum open space standard currently
used in the RL-2 zoning district addresses similar objectives.
Community Feedback
Participants in both the community workshops and property-owner
survey expressed concern with loss of green space, lot coverage and
impervious or paved surfaces. Survey participants, however, were
most concerned with the percentage of a lot covered by buildings
rather than those covered by other paved surfaces. Paved
Areas
About 49% of survey participants agreed that the loss of green space
when larger buildings are constructed is a key issue (18% strongly
agreed), 15% did not indicate particular agreement or disagreement
and 37% disagreed (16% strongly disagreed).
About 45% of survey participants agreed that a limit on the percentage
of paved surfaces on a lot should be considered (13% strongly agreed), Lot coverage standards dictate a
19% did not indicate particular agreement or disagreement and 35% maximum percentage of a lot sur-
face that can be covered, such as
disagreed (13% strongly disagreed).
by buildings or paved areas. The
Recommendation illustration above shows a lot cover-
age of 40%.
Because building coverage standards would more directly address
the refined problem statement, lot coverage standards are not
recommended.
January 12, 2009 Page 31
Part 3: Potential Tools Strategy Report
Building Coverage Diagram Building Coverage
Building coverage standards establish the maximum percentage of
a lot surface that may be covered by buildings. The Boulder Revised
Code (BRC) defines building coverage as the maximum horizontal area
Accessory within the outer perimeter of the building walls, dividers, or columns at
Structure ground level or above, whichever is the greater area, including, without
limitation, courts and exterior stairways, but excluding:
(1) Uncovered decks, porches, patios, terraces, and stairways all less
than thirty inches high; and
Principal (2) The outer four feet of completely open, uncovered, cantilevered
Structure balconies that have a minimum of eight feet vertical clearance
below.
In other communities, additional elements are sometimes excluded (in
part or in whole) from building coverage to provide additional flexibility
or to promote specific design elements. These may include:
• Accessory structures
• Roofed front porches
• Any deck or patio areas that are not roofed
• Gazebos that are not enclosed on more than two sides
Advantages of building coverage standards:
• Helps maintain open space
• Helps preserve side and rear yard areas
• Mitigates privacy impacts by discouraging larger structures from
extending substantially into the rear yard
• Can be used to provide an incentive for front porches or de-
Building Coverage Calculation
tached garages/accessory structures
Example
Potential disadvantages of building coverage standards:
• Could encourage taller structures if not combined with specific
Lot Size: 6,000 SF
height or floor area ratio standards
Area Covered by
Principal: 1,300 SF Existing Standards
Area Covered by A maximum overall building coverage requirement is not currently
Accessory: 500 SF used for standard lots within the project area. However, the zoning
Total Area Covered: 1,800 SF districts within the project area include a maximum building coverage
standard of 500 SF for accessory structures located within the
1,800 / 6,000 = 30% Lot rear setback for the primary structure. Additionally, overall building
Coverage* coverage may not be increased without a variance on lots that are
*Not including a recommended excep- one half to one fourth of the minimum permitted lot size depending
tion for a portion of the footprint of a de- on the zoning district.
tached accessory structure.
Page 32 January 12, 2009
Strategy Report Part 3: Potential Tools
Community Feedback
Participants in both the community workshops and the property-
owner survey expressed concern with loss of privacy, green space
and overall building coverage.
About 62% of survey participants agreed that a large house next
door diminishes privacy in others’ back yards (26% strongly agreed),
12% did not indicate particular agreement or disagreement and 26%
disagreed (9% strongly disagreed).
About 56% of survey participants agreed that a limit on the percentage
of building coverage should be considered (18% strongly agreed),
17% did not indicate particular agreement or disagreement and 27% Scenario A on the property owner
disagreed (11% strongly disagreed). survey illustrated a 36% lot coverage
(including the primary and acces-
For survey scenario A which illustrated a building coverage of 36% sory structure) on a 7,000 square
(including both the primary and accessory structure) on a 7,000 SF foot lot.
lot, about 26% of survey participants agreed that building coverage
was compatible (10% strongly agreed), 11% did not indicate particular
agreement or disagreement and 63% disagreed (22% strongly
disagreed).
For survey scenario B which illustrated a building coverage of 26%
(including both the primary and accessory structure) on a 7,000 SF
lot, about 64% of survey participants agreed that building coverage
was compatible (19% strongly agreed), 18% did not indicate particular
agreement or disagreement and 18% disagreed (4% strongly
disagreed).
For survey scenario D which illustrated a building coverage of 31%
(including both the primary and accessory structure) on a 7,000 SF
Scenario B on the property owner
lot, about 44% of survey participants agreed that building coverage survey illustrated a 26% lot coverage
was compatible (15% strongly agreed), 19% did not indicate particular (including the primary and acces-
agreement or disagreement and 37% disagreed (9% strongly sory structure) on a 7,000 square
disagreed). foot lot.
Recommendation
Building coverage standards for primary and accessory structures
should be applied to address impacts associated with buildings
covering larger lot areas such as loss of privacy and green space.
To provide an incentive for one-story street elements and breaking
up building mass, one-story front porches and 250 to 500 SF of
a detached accessory structure should be excluded from building
coverage calculations.
Scenario D on the property owner
survey illustrated a 31% lot coverage
(including the primary and acces-
sory structure) on a 7,000 square
foot lot.
January 12, 2009 Page 33
Part 3: Potential Tools Strategy Report
Open Space Standards
Open space standards may generally be described as the inverse
of lot coverage standards. That is, they specify a minimum amount
of open space rather than a maximum area that may be covered by
buildings or other surfaces and structures.
Open space standards may differ from lot coverage standards when
specific standards are set for the quality or location of the required
open space. They are also more likely to be applied at a neighborhood,
or framework, level, specifying the minimum amount of combined
open space for a larger development.
Existing Standards
A minimum open space standard of 6,000 SF per dwelling unit is
currently applied in the RL-2 zoning district.
Community Feedback
Participants in both the community workshops and property-owner
survey provided substantial feedback regarding neighborhood green
space and backyard open space as described in the lot coverage
section.
Recommendation
A minimum backyard open space standard is recommended as part
of the strategy options described in Part 4.
Page 34 January 12, 2009
Strategy Report Part 3: Potential Tools
Landscape Buffering Standards Landscape Buffer Diagram
Landscape buffering standards apply vegetation to the task of
screening incompatible structures and uses. Most frequently used
Required
where commercial or industrial uses abut single-family residential
Landscape
uses, landscape buffering may have a role in protecting the privacy
Buffer
of side and rear yards or in screening parking areas from neighbors
or the street.
Landscape buffering is usually described as a planting area of a
specified width along the property line. Detailed requirements for the
plant material, often stated per 100 linear feet of buffer, ensure that
adequate buffering occurs. Some buffers also include a requirement
for walls or fences.
Advantages of landscape buffering standards:
• Evergreen vegetation provides a visual and functional screen be-
tween new development and existing homes.
• Additional vegetation has a beneficial effect on air quality and
helps reduce the heat island effect of paved areas.
Potential disadvantages of landscape buffering standards:
• Landscape buffering could limit the ability to provide adequate
solar access if placed in some locations.
• Most current landscape buffering requirements do not buffer “like
from like,” meaning single-family homes next to other single-
family homes, because these are usually considered compatible Landscape buffering standards may
enough not to require a buffer. be used to screen parking areas from
• May be difficult to enforce. the street. They may include planting
height requirement or an allowance
Existing Standards for landscaped berms.
Landscape buffering standards are currently used adjacent to
wetlands, residential development in industrial areas, parking areas
for two single-family dwelling on a lot, and subdivisions bordering
noise sources.
Recommendation
Because landscape buffering standards would be difficult to administer
and enforce at a city wide level, they are not recommended.
January 12, 2009 Page 35
Part 3: Potential Tools Strategy Report
Landscape Volume Ratio (LVR) Standards
LVR measures soft vegetative volume. In mature residential
communities this can be as important as building volume because
lots are likely covered with mature landscaping. In many older
neighborhoods, landscape volume may be larger than building volume.
A tear down is likely to result in a loss of mature vegetation. The LVR
provides a means of measuring this. A suburban area will typically
have a higher ratio than an urban area, although large older canopy
trees often skew this difference.
Advantages of landscape volume ration (LVR) standards:
• Unlike most buffer systems, LVR is sensitive to the actual height
and volume of both existing and proposed trees and other vegeta-
tion.
• Relates amount of vegetation on the site to the size of the lot
(large lots will require more vegetation to reach the same ratio).
Potential disadvantages of landscape volume ration (LVR)
standards:
• Difficult to calculate and enforce.
• Volume ratio does not specify placement of vegetation to serve
as a screen.
• Is not as effective in the winter when deciduous trees lose their
leaves.
Existing Standards
Landscape volume ratio standards are not currently used in the
project zoning areas.
Recommendation
Because LVRs are difficult to measure and enforce and are not as
effective in climates where trees lose their leaves in the winter, LVR
standards are not recommended.
Page 36 January 12, 2009
Strategy Report Part 3: Potential Tools
Setback Standards Setback Diagram
Setback standards dictate how close buildings may be placed to the
front, sides or rear of a lot. The setback is usually calculated as the
Side and Rear Setbacks for Acc.
distance from the property line to the edge of the nearest building.
Structure
Taken together, front, side and rear setback standards define the
area of the lot where structures may be built.
Advantages of setback standards:
• Front setbacks help maintain a continuous pattern of open space
along a block. Rear
• Side and rear setback standards can protect privacy (especially Setback
when new construction involves a two-story building) by ensur-
ing that buildings on adjoining lots are separated by a minimum
distance.
• Incentives can also be included in setback standards to pro-
mote desirable design elements such as front porches or build-
ings that step down towards their neighbors (i.e. allowing front
porches to encroach into the setback or providing different side
setback standards for one and two-story building elements).
Potential disadvantages of setback standards: Front
• In areas with varied setbacks, increased setback standards Setback
could cause some structures to become non-standard.
Current Standards
Front, side and rear setback standards for both the primary and
accessory structures are currently used within all zoning districts in Side Side
the project area. Setback 1 Setback 2
Community Feedback
Participants in both the community workshops and property-owner
survey expressed concern with issues that could be associated with
setbacks such as loss of privacy and green space as well as concern
with the height and character of building walls near the side setback.
Survey responses that could relate to setbacks are included in the
lot coverage, building coverage and wall sculpting sections.
Recommendation
Increased side and rear setback standards are a recommended
option. This would help to maintain a sense of space and mitigate
privacy concerns.
January 12, 2009 Page 37
Part 3: Potential Tools Strategy Report
FAR Diagrams Building Level Tools
Tools such as floor area ratio (FAR) and Cubic Content Ratio (CCR)
standards help to maintain an existing or desired scale in the built
form of the neighborhood. Height, articulation and building module
standards help shape building form, which can reduce perceived scale
and may help mitigate specific impacts on adjacent properties. These
are considered “building level” tools which govern the mass, scale
and general design characteristics of buildings on individual lots.
Floor Area Ratio (FAR) Standards
Floor area ratio standards limit the total square footage of all structures
on a lot. FAR is generally expressed as two decimal digits, calculated
by dividing the total square footage of all structures on a lot by the
total square footage of the lot.
The Boulder Revised Code (BRC) defines FAR as the ratio of the
floor area of a building to the area of the lot on which the building is
situated. The FAR is calculated by dividing the total building area by the
area of the lot, as measured in square feet. The floor area is the total
floor area of all levels, not including a basement, but including 50%
of the floor area of a partially exposed lower level in which less than
50% of the perimeter of the walls of that level are more than two feet
above the adjacent grade, including walk-out levels or terrace levels.
All of the floor area of a partially exposed lower level which exceeds
two feet above grade for 50% or more of the perimeter of the walls is
counted as floor area.
FAR standards do not alter the three-dimensional building envelope
in which structures may be built, but will generally make it difficult or
impossible to build a structure that fills the entire envelope. When
the FAR is set at a level that is less than what otherwise could be
constructed within setback, height and building coverage limits, then
there is the opportunity for variation in building form. That is different
When the FAR is set at a level that design solutions, with different massing arrangements, can occur.
is less than what otherwise could be
constructed within setback, height
and building coverage limits, then
In other communities, additional elements are sometimes excluded
there is the opportunity for varia- (in part or in whole) from FAR to provide additional flexibility or to
tion in building form. That is differ- promote specific design elements. These may include:
ent design solutions, with different • Attic space
massing arrangements, can occur. • Accessory structures
All of the structures illustrated above • Roofed porches
have a floor area ratio of .40 within a
three dimensional building envelope Advantages of FAR standards:
defined by standard setbacks and a • Directly relates the size of structures to the size of the lot
35 foot height limit. • Relatively easy to understand and calculate
• Can be combined with lot coverage and height limits to break
down the overall scale of structures
• Can be used to provide an incentive for front porches or de-
tached garages and accessory structures
Page 38 January 12, 2009
Strategy Report Part 3: Potential Tools
Potential disadvantages of FAR standards: Second
• Could permit inappropriately tall or box-like structures when not Floor
combined with other standards and guidelines
• Could permit inappropriately large structures on large lots First Floor
• Could constrain the building potential of small lots
Existing Standards
A maximum FAR standard of 0.80 is currently used in the RL-1
zoning district. A FAR standard is not currently used in other zoning
districts within the project area. Accessory Principal
Structure Structure
Community Feedback
Participants in both the community workshops and property-owner
survey expressed concern about a loss of privacy and the overall size FAR Calculation Example
of buildings in proportion to their lots. On the other hand, differing
responses on survey questions related to overall building size may
indicate that others feel that new construction occurring in their Lot Size: 6,000 SF
neighborhoods is acceptable. Principal 1st Floor
Area: 1,300 SF
About 43% of survey participants agreed that some recent construction
Principal 2nd Floor
in their neighborhood was too large (21% strongly agreed), 13% did
not indicate particular agreement or disagreement and 45% disagreed Area: 900 SF
(21% strongly disagreed). Accessory Floor
Area: 500 SF
As described in the building coverage section, a high percentage of Total Floor Area: 2,700 SF
survey participants agreed that a large house next door diminishes
privacy in others’ back yards. 2,700 / 6,000 = 0.45 FAR*
*Not including a recommended excep-
tion for a portion of the square footage
in a detached accessory structure.
January 12, 2009 Page 39
Part 3: Potential Tools Strategy Report
About 67% of survey participants agreed that requirements should
be set which relate the size of a building to the size of its lot (26%
strongly agreed), 13% did not indicate particular agreement or
disagreement and 21% disagreed (9% strongly disagreed). 59% of
survey participants also indicated that relationship to lot size was
most important among six variables that could help determine the
compatibility of major additions and new construction.
For survey scenario A, which illustrated a FAR of 0.65 (including
both the primary and accessory structure) on a 7,000 SF lot, about
23% of survey participants felt that it was compatible (9% strongly
agreed), 10% did not indicate particular agreement or disagreement
and 68% disagreed (24% strongly disagreed).
Scenario A on the property owner
survey illustrated a 4,054 SF primary For survey scenario B, which illustrated a FAR of 0.45 (including both
structure and a 500 SF detached ac- the primary and accessory structure) on a 7,000 SF lot, about 53%
cessory structure on a 7,000 square
of survey participants agreed that it was compatible (16% strongly
foot lot for a combined total FAR of
0.65. agreed), 20% did not indicate particular agreement or disagreement
and 27% disagreed (6% strongly disagreed).
Recommendation
FAR standards should be used to address impacts associated with
larger buildings such as loss of privacy and green space.
To provide an incentive for one-story street elements and breaking
up building mass, one-story front porches and 250 to 500 SF of
a detached accessory structure should be excluded from FAR
calculations. The actual ratio used should be tailored to differing
contexts. That is, the ratio should vary by zoning district and lot size
category.
Scenario B on the property owner
survey illustrated a 2,650 SF primary
structure and a 500 SF detached ac-
cessory structure on a 3,150 square
foot lot for a combined total FAR of
0.45.
Page 40 January 12, 2009
Strategy Report Part 3: Potential Tools
Sample FAR Illustrations1
Lot Size 7,000 SF
Primary Structure SF (all floors) 3,150 SF
Accessory Structure SF 350 SF
Total SF 3,500 SF
Total FAR 0.50
Lot Size 7,000 SF
Primary Structure SF (all floors) 3,500 SF
Accessory Structure SF 350 SF
Total SF 3,850 SF
Total FAR 0.55
Note that the FARs illustrated on this page exceed the recommended standards described in Part 4.
1
January 12, 2009 Page 41
Part 3: Potential Tools Strategy Report
Bulk Plane Diagram Overall Height
Overall building height standards dictate how tall a building may be.
The Boulder Revised Code (BRC) defines the vertical distance from
the lowest point within twenty-five feet of the tallest side of the structure
to the uppermost point of the roof.
In other communities, height for residential structures is sometimes
measured from grade to the top, or parapet, of flat roof forms, or to
the ridge, middle or eave of a sloped roof form.
Advantages of height standards:
• Helps ensure that structures do not loom over their neighbors
Bulk planes primarily serve to shape • Relatively easy to understand and calculate
the three dimensional “envelope” in • Can be used to provide an incentive for specific roof forms that
which a building can be built. are consistent with a specific neighborhood character or tradi-
tion. (I.e., height may be calculated to the mid-point of a sloped
roof to encourage pitched roof forms).
Potential disadvantages of height standards:
• Could permit inappropriately tall structures near neighbors un-
less combined with other standards.
Existing Standards
A maximum overall height standard of 35’ for primary structures
is currently used in all zoning districts within the project area. The
existing maximum height standard for accessory structures is 20’.
Recommendation
Changes to the existing overall maximum height standards are not
recommended. However, the recommended wall sculpting standards
would set a height limit for building walls near the side setback.
Additional consideration should be given to adjusting the way that
height is measured to reduce potential unintended consequences.
However, because height measurement is included within the city
charter, any changes to the way height is measured would require
a vote of the people.
Bulk Plane Standards
Bulk plane standards shape the maximum permitted three-dimensional
building envelope by limiting the height and mass of building elements
on different parts of a lot. A bulk plane generally rises at a defined angle
from the front, side or rear property line(s) or from the front side or rear
setback(s). It can begin at ground level, or at a predetermined point above
ground level, and continue to rise toward the center of the lot until it meets
the overall height limit or intersects a bulk plane rising from another side of
the lot. Bulk planes ensure that taller portions of a structure are positioned
in the center of the lot, rather than immediately adjacent to neighbors.
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Strategy Report Part 3: Potential Tools
Building elements often exempted from bulk plane standards:
• Chimneys
• Dormers
Advantages of bulk plane standards:
• Restricts taller or more massive building elements to certain portions
of a lot.
• Helps reduce the potential of tall walls or massive structures to ad-
versely affect their neighbors
• Can be combined with lot coverage, FAR and/or CCR standards to
mitigate mass and scale impacts while encouraging creative design
solutions
Potential disadvantages of bulk plane standards:
• May not support existing conditions in areas where some traditional
structures have tall exterior walls
• Can be difficult to visualize or understand
Existing Standards
Bulk plane standards are not explicitly used in the project area. However,
a de facto bulk plane is used in the RL-2 zoning district which currently
specifies a maximum building height based on distance from the side
setback. In addition, the city’s existing solar ordinance is in effect a
dynamic bulk plane regulation that changes with orientation to the sun,
rather than being directly related to side or rear yards.
Recommendation
Because existing solar access regulations have the effect of applying
a relatively complex bulk plane to the north side of lots, the addition of
potentially overlapping bulk plane standards are not recommended.
However, the recommended wall sculpting standards described in Part 4
would promote similar objectives while allowing for additional flexibility.
A bulk plane that rises at a 45 degree angle from a point 10 feet above each
side setback (wall plate height). It rises towards the center of the lot until it
reaches the maximum overall permitted height.
January 12, 2009 Page 43
Part 3: Potential Tools Strategy Report
Articulation and Wall Articulation and Wall Sculpting
Articulation standards further refine the perception of building scale
Sculpting Diagram
by “sculpting” the exterior of buildings. The primary objective is to
Roof Ridge Articulation reduce the perceived mass of a building by dividing it into smaller
components, or “modules.” Articulation can be required in several
different ways or can be required to include a certain number of
methods.
One Story Element
A one-story porch or other element can be required along one or
more building facades. Typically this would be required on the street
front of a building in order to help reduce the apparent mass of the
structure from the street. Incentives can also be included in FAR
or building coverage standards to encourage one-story front porch
Wall Plane Articulation/ elements.
Sculpting
Roof Ridge Articulation
A maximum length area can be established for the ridge line of a roof
One-Story Element
before an offset must occur. This would help minimize the perceived
mass of the roof area.
Wall Sculpting/Wall Height and Length
Wall length and height standards may be combined to help sculpt
building forms and discourage overly large or box-like shapes. Wall
length standards set a maximum length for the wall planes of exterior
building walls before they must jog or incorporate an offset. Wall height
standards set a maximum permitted height for exterior building walls
before they must step back. Wall heights are usually measured from
either grade or the first finished floor to the highest horizontal framing
member, or wall plate, that intersects the wall. This is (usually the
point at which the roof eave meets the wall.)
Wall height standards are often tied to setbacks to help ensure that
taller or more massive building elements are located away from the
edges of a lot. Such wall height standards can shape the permitted
building envelope in a way that is similar to a bulk plane standard.
Wall length standards may be tied to wall height to restrict the length
of two-story walls while allowing longer walls if they are one-story
in height.
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Strategy Report Part 3: Potential Tools
Advantages of articulation and wall sculpting standards:
• Reduces the perceived mass and scale of structures when
viewed from the street
• Helps ensure that the mass of larger infill structures is broken up
to reflect the size of traditional structures
• Encourages division of building mass into modules
• Facilitates varying the setbacks of building walls along the sides
of properties
• Helps mitigate the impacts of large side walls “looming” over
neighbors
Potential disadvantages of articulation and wall sculpting
standards:
• May not support existing conditions in areas where traditional
structures have tall or long walls
• May not support desired interior floor plan layouts
Existing Standards
Specific articulation and wall sculpting standards are not currently
used within the project area. However, the RL-2 zoning district
currently specifies a maximum building height based on distance
from the side setback. This standard could affect the character of
building walls.
Recommendation
Wall sculpting standards are recommended to limit the permitted
length of a two-story wall at the side setback. The length of one-
story walls would not be limited. Incentives for one-story front porch
elements are also recommended.
January 12, 2009 Page 45
Part 3: Potential Tools Strategy Report
Cubic Content Ratio (CCR) Standards
Cubic Content Ratio standards limit the total volume of all structures
on a lot. CCR is generally expressed as a whole number with two
decimal digits. It is calculated by multiplying the maximum exterior
height, width and depth of a structure and dividing the result by the
total square footage of the lot. If a CCR standard of 7.50 was applied
to a 10,000 square foot lot, a 15 foot tall (1-story) house could be
about 70 feet wide and 71 feet deep. Both floors of a 30 foot tall
(two-story) house could be approximately 50 feet wide and 50 feet
deep. CCR standards do not directly alter the dimensions of the
three-dimensional envelope in which buildings may be built. A CCR
standard, however, will generally make it difficult or impossible to
build a structure that fills the entire envelope. Accessory structures
and porches are sometimes excluded from CCR calculations.
Advantages of CCR standards:
• Directly relates the scale of structures to the size of the lot
• May encourage lower floor-to-floor heights
• Can be combined with lot coverage and height limits to break
down the overall scale of structures
• Can be used to provide an incentive for front porches or de-
tached garages and accessory structures
Potential disadvantages of CCR standards:
• Could encourage overly box-like structures when not combined
with other standards and guidelines
• Could discourage wall sculpting and articulation
• Could permit overly large structures on large lots
• Could constrain the building potential of small lots
• Very difficult to calculate and understand
Existing Standards
CCR standards are not currently applied within the project area.
Recommendation
Because it is difficult to calculate and understand and could discourage
articulated wall planes or other creative design solutions, the addition
of a CCR standard is not recommended.
C
B
The primary structure illustrated above is on a 7,500 square foot
lot and is 35 feet wide (A), 50 feet deep (B) and 23 feet high (C).
The resulting CCR is 5.37. A box shaped structure filling the entire A
blue envelope area would have the same CCR.
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Strategy Report Part 3: Potential Tools
Design Guidelines
Design guidelines are often combined with design standards to provide
an additional level of detail and help ensure that a specific project is
appropriate for its context. They can address many aspects of design,
including those at the neighborhood, site and building levels.
Design guidelines provide for flexibility and discretion. Some
interpretation will generally be needed to consider the interaction
between guidelines and whether a specific design solution meets the
overall intent of the guidelines. While the criteria for consideration
should be as objective as possible, some judgment may be required
to allow for flexibility in meeting the intent of the guideline.
Advantages of design guidelines:
• Helps ensure that rehabilitation and new construction is context-
appropriate
• Allows for flexible design solutions
• May address a detailed level of design
Design guidelines may be used to
Potential disadvantages of design guidelines: support a design review process that
provide an additional level of detail
• Requires interpretation
and allows for a high level of context
• May not provide predictable outcomes sensitivity in the design approval
• May require significant resources to administer process.
Sample Design Guideline Format
5.0 Building Mass Guideline Illustrations
Design Objective
A building should be articulated to appear similar in scale to others in the
neighborhood. Excessive building mass should be avoided. A hillside location
heightens the perceived scale of a building. Special consideration should be given
in these situations to minimize impacts. An analysis of building forms in the area
should be an explicit element in the design of any project.
Design Guideline
5.1 Divide a larger building mass into modules to reduce its perceived
size.
Guideline Application Points
• To avoid long, uninterrupted wall planes provide changes in wall setbacks,
especially along the sides of a property. (See Guideline 5.11)
• Vary the roof profile as a series of elements, avoiding long extended lines.
January 12, 2009 Page 47
Part 3: Potential Tools Strategy Report
Existing Design Guidelines
With the exception of historic districts, design guidelines are not
currently used in the city’s single-family residential neighborhoods.
Community Feedback
As described earlier in this section, some participants in the
community workshops, interest groups and property-owner survey
expressed a desire for context-specific design review strategies for
neighborhood development.
About 41% of survey participants felt that one of the actions the city
should take was to establish a design review and approval process
that is tailored to individual neighborhoods.
Recommendation
Development of general advisory design guidelines is recommended
for single-family residential neighborhoods. Future consideration
should also be given to neighborhood based design guidelines,
or guidelines that would apply at a certain development threshold
(i.e., once a building reaches a certain square footage or FAR). As
The Landmarks Board currently uses
design guidelines to review projects described earlier in this section, neighborhood planning would assist
in the city’s designated local historic with this effort,
districts such as Mapleton Hill.
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Strategy Report Part 3: Potential Tools
Application Approaches
Each potential tool could be applied in different ways. Several
approaches are discussed below, including:
• Applying a uniform new standard to single-family districts through-
out the city
• Varying the standards by neighborhood or other described area
• Varying the standards by embedding them in the various zoning
districts
• Varying the standards by applying them based on the size of the
lot proposed for development
• Applying the standards in only certain zoning districts, neighbor-
hoods or areas
Apply Tools Uniformly Throughout the Project
Area
The recommended tools could by applied in a uniform manner across
the project area. That is, application of the tools would not vary based
on zoning district, lot size or other criteria. For example, a new maximum
building coverage limit of 30% could be applied to all properties in the
project area.
Advantage of Uniform Application:
• Simple to administer and enforce
Potential Disadvantage of Citywide Application:
• “One Size Fits All” – may have unintended consequences due to
its broad application in all situations
Recommendation
Uniform application of the tools is not recommended because this
approach would not recognize substantial differences in existing context
and development patterns in different parts of the project area.
January 12, 2009 Page 49
Part 3: Potential Tools Strategy Report
Vary Application by Neighborhood or Area
The recommended tools could be applied differently depending on
specific neighborhoods or areas. For example, a certain building
coverage standard could be applied in Newlands and a different
building coverage standard could be applied in Martin Acres, both of
which are currently within the RL-1 zoning district.
Advantages of Varying Application by Neighborhood or Area:
• Avoids the “one size fits all” issues of a uniform approach
• Allows specific numeric standards to be developed for each neigh-
borhood or area
• Sensitive to context
Disadvantages of Varying Application by Neighborhood or Area:
• May be difficult to determine where these areas should be
mapped
• Multiple standards in different areas may be harder to enforce
• May depend on time-consuming neighborhood planning efforts
Recommendation
As future neighborhood planning efforts are completed, an evaluation
of potential tools and application strategies is recommended. Varying
the application of specific tools by neighborhood could be considered
to support plan goals. Until additional neighborhood planning efforts
are completed, however, it is recommended that the recommended
tools not be applied differently by neighborhood or area.
Note that varying application of the recommended tools by lot size would
capture some of the advantages of neighborhood-specific application
because lot size is a significant defining feature that helps differentiate
neighborhoods and areas.
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Strategy Report Part 3: Potential Tools
Vary Application by Zoning District
Much like to varying the standards by neighborhood or area, varying
them by zoning district is possible. This approach assumes that areas
zoned similarly have similar problems and should be treated in similar
fashion.
Advantages:
• Avoids the “one size fits all” issues of a citywide approach.
• Allows specific numeric standards to be developed for each dis-
trict.
Disadvantages:
• Zoning districts may not be similar in character.
• Multiple standards in different areas may be harder to enforce.
Recommendation
Varying standards by zoning district and lot size is recommended to
promote context sensitivity and reduce the possibility that updated
standards could result in non-standard building conditions.
Vary Application by Lot Size
One possible approach to matching homes to their underlying lot
size is to establish standards that vary by the lot size itself. When the
standards were applied to smaller lots, the result would be a smaller
house.
• Avoids the “one size fits all” issues of a citywide approach.
• Allows specific numeric standards to be developed for each lot
size. Matches house size to underlying lot.
Disadvantages:
• Multiple standards in a given zoning district may be harder to ad-
minister and enforce.
Recommendation
Varying standards by zoning district and lot size is recommended to
promote context sensitivity and reduce the possibility that updated
standards could result in non-standard building conditions.
January 12, 2009 Page 51
Part 3: Potential Tools Strategy Report
Apply Tools Only in Certain Zoning Districts,
Neighborhoods or Areas
The recommended tools could be applied only to certain zoning districts,
neighborhoods or areas. For example, they could be applied only in
the RL-1 zoning district with no changes made in any other district.
The final option worth considering is using a combination of the
approaches. Some tools may be appropriately implemented on a
citywide basis, while others relate to a specific area, and still others
to small or large lots. This fine-grained combination would likely yield
the best result.
Recommendation
Public feedback has indicated that concern with compatible development
exists in single-family neighborhoods throughout the city. Therefore,
applying the tools only in certain areas is not recommended. However,
consideration may be given to removing certain neighborhoods or
zone districts from the project area. For example, based on survey
responses, consideration may be given to pursuing an application
approach that would not apply the recommended tools to single-family
properties in Gunbarrel.
Page 52 January 12, 2009
Part 4: Recommended
Strategy
A strategy to promote compatible development in single-family
neighborhoods should address the refined problem statement
presented in Part 2 as well as the broad array of community feedback
received to date. It must also consider City Council’s goals and
objectives for the project including the need to maintain flexibility,
provide for changing needs, promote variety and ensure fairness.
The recommended strategy would apply to single-family properties
in each of the project area’s zoning districts. Each district is briefly
described in Part 2. The zoning districts are:
• Residential - Rural 1 (RR-1)
• Residential - Rural 2 (RR-2)
• Residential - Estate (RE)
• Residential - Low 1 (RL-1)
• Residential - Low 2 (RL-2)
• Residential - Mixed 1 (RMX-1)
Goals and Objectives
The recommended strategy is intended to address the refined problem
statement while also promoting a series of goals and objectives
adopted by City Council. Note that a separate economics report will be
prepared to provide a broad economic analysis and discuss specific
economic considerations related to the recommended strategy. The
goals and objectives adopted by City Council are:
• It is very important to retain flexibility for people to alter their The recommended strategy includes
homes as their needs change, since many can’t afford to move several options for use of the potential
to another house. However, there is a threshold of pops over tools described in Part 2.
which these additions can be “too much.” It is important to pro-
vide for appropriate change over time.
• Ensure that solutions promote variety as opposed to monotony.
• Ensure that all neighborhoods or certain lots with characteristics
different from one another are treated fairly and equitably.
• Include an efficient process to address unintended consequenc-
es (an appeal or variance process).
• Include analysis of broad economic impacts.
January 12, 2009 Page 53
Part 4: Recommended Strategy Strategy Report
Considerations for Developing a Recommended Strategy
Each potential tool described in Part 3 was considered for inclusion in the recommended strategy. The
following criteria listed below were used to determine which tools and application approach would most
effectively address the refined problem statement, overall public feedback and City Council’s goals and
objectives. The specific tools that best meet these criteria are further described in the strategy options
presented in the next section.
1. Effectiveness
The tool should directly address a specific issue identified in the problem statement. A tool that more
directly addresses an issue is preferred. For example, using a FAR standard to regulate overall building
mass as described in the strategy options directly addresses the issue and is therefore preferred. The
strategy options also describe using a combination of height limits, setbacks and building coverage
standards to address overall building mass. However, this option would not address the issue as directly
as an FAR standard.
2. Fairness
Council’s goals and objectives direct that all properties of a similar class should be treated equally. For
example, the standards should be the same for all similarly sized lots located within the same zone
district as described in the recommended application section.
3. Predictability
The regulations should be understandable by all parties. That is to say, a property owner should be
able to predict a likely outcome of the approval process if they follow the regulations. City staff should
be able to easily interpret the regulations, and neighborhoods should have a reasonable understanding
of the scale of building that potentially can occur. Each strategy option includes a limited set of discrete
dimensional standards to ensure predictability.
4. Efficiency
The regulations, and the permitting process that is employed, should be simple to understand and
administer, such that time is used efficiently to develop an improvement plan and obtain approvals.
This applies to the applicant, city staff and other decision-makers. In general, a system that uses easily
interpreted prescriptive standards as described in the strategy options is most efficient.
Page 54 January 12, 2009
Strategy Report Part 4: Recommended Strategy
5. Context Sensitivity
A system that responds to differences in context is also desirable as reflected in the property-owner
survey responses and other community feedback indicating that some form of design review should be
implemented at the neighborhood level. Fine-tuning the tools for different lot sizes in each zone district,
as described in the recommended application section, provides a measure of context-sensitivity. Context
sensitivity could be increased through use of voluntary design guidelines, design guidelines that would
apply to development beyond a defined threshold (such as a specific building coverage or FAR) or
neighborhood-based design guidelines.
6. Flexibility
A system that provides some flexibility is also desirable as described in Council’s goals and objectives.
While this may seem to contradict the objective of predictability, the recommended tools can be calibrated
to ensure the potential for property owners to meet changing needs using creative design solutions.
Consideration of methods for alternative compliance or future use of design guidelines could increase
options for flexibility. Such methods would recognize public feedback that some larger buildings could
be compatible if they were well designed.
7. Interface with Existing Regulations and Address Unintended Consequences
Opportunities to refine existing regulations are typically preferred, rather than creating new categories
of regulation. For example, a FAR standard is already in place. Adjusting and applying it to additional
zoning districts as described in the strategy options may be easier than drafting a new regulation.
Any new tools should not conflict or have unnecessary overlap with existing regulations. For example,
a bulk plane tool is not recommended because it would overlap and potentially conflict with the city’s
existing solar access ordinance.
New tools could also be used to address the potential unintended consequences of existing regulations.
The solar ordinance, for example, encourages a stepped building form, which reduces the perceived
mass on one side of a property but may encourage long, tall, walls on the other. The wall sculpting tools
described in the strategy options may help address this unintended consequence.
January 12, 2009 Page 55
Part 4: Recommended Strategy Strategy Report
Strategy Options
The recommended tools may be combined and used in several different ways to address the refined
problem statement and promote compatible development in single-family neighborhoods. This section
describes a series of strategy options for further consideration.
Dimensional Standards
The dimensional standards suggested in the strategy options include specific numerical standards such
as a maximum FAR and building coverage. They are based primarily on public feedback received to
date. For example, property-owner survey participants generally felt that the 0.45 FAR (including both
the primary and detached accessory structure) illustrated in survey scenarios B, C and D, represented
compatible development on a 7,000 SF lot. Therefore, the strategy options include a suggested maximum
FAR standard of 0.42 for lot sizes between 6,000 and 7,999 SF with a 350 SF accessory structure
exceptions (allowing for a total FAR of 0.45 on a 7,000 SF lot with detached accessory structure).
The suggested dimensional standards are intended to provide a starting point for discussion of the
recommended tools and will be adjusted based on public feedback and additional analysis. It is
recommended that the dimensional standards vary by zone district and lot size as described in the
recommended application section. Each strategy option is presented as a “package” of regulations and
would only be effective if all of the tools described are used in combination.
Basic Elements of the Strategy Options
The basic elements of the proposed actions are listed below. Public feedback and consultation with
elected officials will provide direction for further development of the tools included in each option.
Correlate Overall Building Size to Lot Size
Regulations that directly influence overall building size are proposed. The options include the following
tools:
• Maximum floor area ratio (FAR) requirements
• Maximum building coverage requirement
• Minimum open space requirement
• Increased setback requirements
Reduce Perceived Building Mass
Regulations that require, and sometime encourage, breaking up the mass of a building fit into this
category. Options include:
• Maximum two-story wall plane length requirement at the side yard setback
• Maximum wall plate height requirement at the side yard setback
• Incentives for breaking up building mass into a primary structure and a detached accessory struc-
ture
Preserve Open Space in the Rear of Properties
Regulations that limit building in the rear are proposed. Options include:
• Increased rear yard setback requirement
• Minimum back yard open space requirements
• Maximum building coverage requirements
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Strategy Report Part 4: Recommended Strategy
Measurement of Recommended Standards
Each of the tools included in the strategy options is described in Part
3. Detailed definitions will be drafted for any tool that is selected for
further development. Such definitions will be included and clearly
illustrated within the city’s code. General information on how each
recommended tool would be measured is provided below. Note that the
strategy options include a recommended FAR, rear yard open space
and building coverage exception for detached accessory structures.
Building Coverage
FAR is the ratio of floor area above
It is assumed that the recommended standard described in the strategy the basement to the area of the lot on
options would be measured according to the Boulder Revised Code which the building is situated.
(BRC) definition of building coverage. If this tool is selected for further
development, refinement of the definition may be considered. The BRC
defines building coverage as the maximum horizontal area within the
outer perimeter of the building walls, dividers, or columns at ground level
or above, whichever is the greater area. This includes, without limitation,
courts and exterior stairways, but excluding:
(1) Uncovered decks, porches, patios, terraces, and stairways all less
than thirty inches high; and
(2) The outer four feet of completely open, uncovered, cantilevered
balconies that have a minimum of eight feet vertical clearance below.
Floor Area Ratio (FAR)
It is assumed that the recommended standard described in the strategy
options would be measured according to the Boulder Revised Code
(BRC) definition of FAR. If this tool is selected for further development,
refinement of the definition may be considered. The BRC defines FAR
as the ratio of the floor area of a building to the area of the lot on which
the building is situated. The FAR is calculated by dividing the total Wall plate height is measured to the
building area by the area of the lot, as measured in square feet. The top horizontal framing member of a
floor area is the total floor area of all levels, not including a basement, wall from grade.
but including 50% of the floor area of a partially exposed lower level
in which less than 50% of the perimeter of the walls of that level are
more than two feet above the adjacent grade, including walk-out levels
or terrace levels. All of the floor area of a partially exposed lower level
which exceeds two feet above grade for 50% or more of the perimeter
of the walls is counted as floor area.
Rear Yard
For the purposes of the rear yard open space standard described in the
strategy options, the rear yard is considered to be the rear half of the
property. More specific measurement definitions will be developed.
Wall Plate Height
For a building with a flat or sloping roof, the wall plate height is the
height to the top horizontal framing member of a wall from grade. More
specific height measurement definitions will be developed.
Wall Length
Wall length is the continuous length of building wall without horizontal
offsets or height changes as described in the strategy options.
January 12, 2009 Page 57
Part 4: Recommended Strategy Strategy Report
Strategy Option 1: Combine FAR, Building Coverage and Wall Sculpting
This option combines the tools described below to address the refined problem statement. The specific
dimensions for each tool would be calibrated to recognize traditional development patterns while
permitting an increment of change for additions and new construction. As described in the recommended
application section, the specific dimensions for each tool would vary by zone district and lot size. The
recommended dimensions described below would apply to a 7,000 SF lot in the RL-1 zoning district.
This strategy option is recommended because it most directly meets the criteria for addressing
the refined problem statement.
Floor Area Ratio (FAR)
A FAR standard would be used to relate building size to lot size and address mass and scale or looming
impacts on adjoining properties. For a 7,000 SF lot in the RL-1 zoning district, the maximum FAR would
be 0.42. An exception to the FAR standard is recommended for a portion of any detached accessory
structures to encourage breaking down overall mass as described in the recommended application
section.
Building Coverage
A building coverage standard would be used to help preserve rear yard open space and reduce privacy
impacts on adjoining properties. For a 7,000 SF lot in the RL-1 zoning district, the maximum building
coverage would be 25%. An exception to the building coverage standard is recommended for a portion
of any detached accessory structures to encourage breaking down overall mass as described in the
recommended application section.
Wall Sculpting
Wall height and length standards would help mitigate looming and privacy impacts on adjacent properties
by limiting wall dimensions near the side setback. For a 7,000 SF lot in the RL-1 district, maximum wall
plate height at the minimum side setback would be 22’ with the maximum height increasing by 1’ for each
foot from the side setback. Within 5’ of the minimum side setback, a maximum wall length standard of
45’ would apply to any walls between 12’ in height and the maximum wall height. At the maximum wall
length, the wall height limit would be reduced to 12’ or a minimum 5’ wall offset would be required.
Page 58 January 12, 2009
Strategy Report Part 4: Recommended Strategy
Strategy Option 1: Combine FAR, Building Coverage and Wall Sculpting
The illustrations on this page show multiple views of a single-family residential property developed to the
maximum FAR, lot coverage and wall sculpting standards included in strategy Option 1. The illustrated
new construction also meets existing code requirements such as minimum setbacks, maximum overall
height and solar access requirements. Note that one-story elements are encouraged by the interaction
of the FAR and building coverage standards.
Illustrated Standards for Strategy Option 1 in the RL-1 Zoning District
Lot Size 7,000 SF
Max. Building Coverage 25%
Max. FAR 0.42
SF Excepted from FAR and Bldg. Cover
350
for a Detached Accessory Structure
Max. Wall Plate Height at Side Setback1 22’
Max. Length for Walls over 12’ in Height 2
45’
Min. Offset at Max. Wall Length 5’
Wall plate height may increase by 1’ for each additional 1’ from the side setback.
1
2
For continuous building walls with a plate height over 12’ and without a minimum offset as noted.
January 12, 2009 Page 59
Part 4: Recommended Strategy Strategy Report
Strategy Option 2: Combine Rear Yard Open Space and Wall Sculpting
This option combines the tools described below to address the refined problem statement. This option
does not include additional or revised FAR standards. The specific dimensions for each tool would be
calibrated to recognize traditional development patterns while permitting an increment of change for
additions and new construction. As described in the recommended application section, the specific
dimensions for each tool would vary by zone district and lot size. The recommended dimensions described
below would apply to a 7,000 SF lot in the RL-1 zoning district.
This option could be considered if the city did not intend to modify the existing FAR standards. It would,
instead, rely upon open space standards and wall height limits to mitigate impacts of larger buildings
and to maintain privacy. Because this option does not include an FAR standard, it could potentially allow
for a larger structure (with additional second or third story square footage) than would be permitted by
the other strategy options.
Rear Yard Open Space
A minimum open space percentage for rear yards would directly address open space issues and reduce
privacy impacts on adjoining properties. For a 7,000 SF lot in the RL-1 zoning district, the minimum
amount of rear yard open space would be 90%. An exception to the rear yard open space standard is
recommended for a portion of any detached accessory structures to encourage breaking down overall
mass as described in the recommended application section.
Wall Sculpting
Wall height and length standards would help mitigate looming and privacy impacts on adjacent properties
by limiting wall dimensions near the side setback. For a 7,000 SF lot in the RL-1 district, maximum wall
plate height at the minimum side setback would be 22’ with the maximum height increasing by 1’ for each
foot from the side setback. Within 5’ of the minimum side setback, a maximum wall length standard of
45’ would apply to any walls between 12’ in height and the maximum wall height. At the maximum wall
length, the wall height limit would be reduced to 12’ or a minimum 5’ wall offset would be required.
Page 60 January 12, 2009
Strategy Report Part 4: Recommended Strategy
Strategy Option 2: Combine Rear Yard Open Space and Wall Sculpting
The illustrations on this page show multiple views of a single-family residential property developed to the
minimum rear yard open space and wall sculpting standards included in strategy Option 2. The illustrated
new construction also meets existing code requirements such as minimum setbacks, maximum overall
height and solar access requirements.
Illustrated Standards for Strategy Option 2 in the RL-1 Zoning District
Lot Size 7,000 SF
Min. Rear Yard Open Space 90%
SF Exception from Rear Open Space for
350
a Detached Accessory Structure
Max. Wall Plate Height at Side Setback1 22’
Max. Length for Walls over 12’ in Height2 45’
Min. Offset at Max. Wall Length 5’
Wall plate height may increase by 1’ for each additional 1’ from the side setback.
1
For continuous building walls with a plate height over 12’ and without a minimum offset as noted.
2
January 12, 2009 Page 61
Part 4: Recommended Strategy Strategy Report
Strategy Option 3: Combine FAR and Setbacks
This option combines the tools described below to address the refined problem statement. The specific
dimensions for each tool would be calibrated to recognize traditional development patterns while
permitting an increment of change for additions and new construction. As described in the recommended
application section, the specific dimensions for each tool would vary by zone district and lot size. The
recommended dimensions described below would apply to a 7,000 SF lot in the RL-1 zoning district.
This option addresses lot coverage by establishing a greater rear yard setback than presently exists,
rather than applying a building coverage limit. Although building coverage or open space standards
would generally provide greater flexibility over increased setback standards, this strategy option may be
considered to provide flexibility for large structures on larger lots if sufficiently set back from adjoining
properties. This strategy option also includes a provision for reduced setback standards on existing
non-standard lots in the RR and RE zoning districts to ensure that development options are available
on small lots. The advantage of this approach is that this limit is one already used by the city. However,
it is a less direct approach to addressing open space.
Floor Area Ratio (FAR)
A FAR standard would be used to relate building size to lot size and address mass and scale or looming
impacts on adjoining properties. For a 7,000 SF lot in the RL-1 zoning district, the maximum FAR would
be 0.42. An exception to the FAR standard is recommended for a portion of any detached accessory
structures to encourage breaking down overall mass as described in the recommended application
section.
Setbacks
Revised setback standards would be used to help preserve rear yard open space and reduce privacy
impacts on adjoining properties. For a 7,000 SF lot in the RL-1 zoning district, the minimum front and
side yard setbacks would not be changed from those provided within existing zoning regulations. The
rear yard setback would, however, be increased to 60’.
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Strategy Report Part 4: Recommended Strategy
Strategy Option 3: Combine FAR and Setbacks
The illustrations on this page show multiple views of a single-family residential property developed to the
maximum FAR and minimum setbacks included in strategy Option 3. The illustrated new construction
also meets existing code requirements such maximum overall height and solar access requirements.
Note that side and rear setbacks would be increased for larger lots.
Illustrated Standards for Strategy Option 3 in the RL-1 Zoning District
Lot Size 7,000 SF
Min. Side Setback 5’
Min. Combined Side Setback Total 15’
Min. Rear Setback for Primary Structure 60’
Max. FAR 0.42
January 12, 2009 Page 63
Part 4: Recommended Strategy Strategy Report
Recommended Application
Regardless of the strategy option selected, it is recommended that the tools be applied throughout the
project area, varying by zoning district and lot size. This approach assumes that areas zoned similarly
have similar problems and should be treated in similar fashion and addresses both fairness and a desire
for context-sensitivity without the need for extensive neighborhood planning efforts.
The tables below and on page 65 summarize the recommended application of each strategy option by
zoning district and lot size. Note that special provisions could be made for lots that are sized just below
a lot size category break to ensure that property owners are not unfairly penalized.
Summary of Recommended Strategy Options
for the RL-2 and RMX-1 Districts
4,000 to 6,000 to 8,000 to > 15,000
Lot Size: 30,000
Lot Size: < 6,000 SF4
7,999 SF 14,999 30,000 SF SF
STRATEGY OPTION 1
Max. Wall Plate Height at Side Setback1 22’ 22’ 22’ 22’ 22’
Max. Length for Walls over 12’ in Height 2
50’ 45’ 45’ 45’ 45’
Min. Offset at Max. Wall Length 5’ 5’ 5’ 5’ 5’
SF Excepted from FAR and Bldg. Cover
350 350 500 500 500
for a Detached Accessory Structure
Max. Building Coverage3 30% 25% 20% 20% 15%
Max. FAR 3
0.45 0.42 0.35 0.30 0.25
STRATEGY OPTION 2
Max. Wall Plate Height at Side Setback1 22’ 22’ 22’ 22’ 22’
Max. 2-Story Wall Length 2
50’ 45’ 45’ 45’ 45’
Min. Offset at Max. Wall Length 5’ 5’ 5’ 5’ 5’
SF Excepted from Rear Yard Open Space
250 350 500 500 500
for a Detached Accessory Structure
Min. Rear Yard Open Space3 80% 90% 90% 95% 95%
STRATEGY OPTION 3
SF Excepted from FAR for a Detached
350 350 500 500 500
Accessory Structure
Min. Side Setback for RL-1 5’ 5’ 5’ 10’ 10’
Min. Combined Side Setback Total for
15’ 15’ 15’ 25’ 30’
RL-1
Min. Side Setback for RR-1 5’ 5’ 10’ 15’ 15’
Min. Side Setback for RR-2 and RE 5’ 5’ 10’ 15’ 15’
Min. Combined Side Setback Total for
15’ 15’ 25’ 35’ 40’
RR-1, RR-2 and RE
Min. Rear Setback (Primary Structure) 55’ 60’ 65’ 70’ 70’
Max. FAR 3
0.45 0.42 0.40 0.35 0.35
1
Wall plate height may increase by 1’ for each additional 1’ from the side setback.
2
For continuous building walls with a plate height over 12’ and without a minimum offset as noted.
3
Not including an exception for detached accessory structures as noted.
4
Lots in this size range are below the minimum lot size for the RR-1, RR-2, RE and RL-1 districts. Standards would apply to
existing non-standard lots. Note that these standards would not be applicable in the RR-1 or RR-2 districts where no lots exist
in this size range.
January 12, 2009 Page 65
Part 4: Recommended Strategy Strategy Report
Option 1 Illustrated on a Small Lot in the RE or RL-1 District
The illustrations on this page show how the option 1 standards could vary on a smaller lot in the RE or
RL-1 zoning districts. Note that this illustrated lot is non-standard (smaller than the existing minimum
lot size standard).
Illustrated Standards for Strategy Option 1
Lot Size 5,400 SF
Max. Building Coverage 30%
Max. FAR 0.45
SF Excepted from FAR and Bldg. Cover
350
for a Detached Accessory Structure
Max. Wall Plate Height at Side Setback1 22’
Max. Length for Walls over 12’ in Height 2
45’
Min. Offset at Max. Wall Length 5’
Wall plate height may increase by 1’ for each additional 1’ from the side setback.
1
For continuous building walls with a plate height over 12’ and without a minimum offset as noted.
2
Page 66 January 12, 2009
Strategy Report Part 4: Recommended Strategy
Option 1 Illustrated on a 12,000 Lot in the RR-1, RR-2, RE or RL-1 District
The illustrations on this page show how the option 1 standards could vary on a smaller lot in the RR-1,
RR-2, RE or RL-1 zoning districts. Note that this illustrated lot is non-standard in the RR-1, RR-2 and
RE districts (smaller than the existing minimum lot size standard).
Illustrated Standards for Strategy Option 1
Lot Size 12,000 SF
Max. Building Coverage 20%
Max. FAR 0.35
SF Excepted from FAR and Bldg. Cover
500
for a Detached Accessory Structure
Max. Wall Plate Height at Side Setback1 22’
Max. Length for Walls over 12’ in Height 2
45’
Min. Offset at Max. Wall Length 5’
Wall plate height may increase by 1’ for each additional 1’ from the side setback.
1
For continuous building walls with a plate height over 12’ and without a minimum offset as noted.
2
January 12, 2009 Page 67
Part 4: Recommended Strategy Strategy Report
Option 1 Illustrated on a Large Lot in the RR-1, RR-2, RE or RL-1 District
The illustrations on this page show how the option 1 standards could vary on a smaller lot in the RR-1,
RR-2, RE or RL-1 zoning districts. Note that this illustrated lot is non-standard in the RR-1, RR-2 and
RE districts (note that this lot size exists primarily in the RR-1 district).
Illustrated Standards for Strategy Option 1
Lot Size 30,600 SF
Max. Building Coverage 15%
Max. FAR 0.20
SF Excepted from FAR and Bldg. Cover
350
for a Detached Accessory Structure
Max. Wall Plate Height at Side Setback1 22’
Max. Length for Walls over 12’ in Height 2
45’
Min. Offset at Max. Wall Length 5’
Wall plate height may increase by 1’ for each additional 1’ from the side setback.
1
For continuous building walls with a plate height over 12’ and without a minimum offset as noted.
2
Page 68 January 12, 2009
Strategy Report Part 4: Recommended Strategy
Implementation Concepts
Several potential approaches may be considered for implementation
of the tools that are developed to promote compatible development. It
will be important to ensure that any new or revised tools are carefully
integrated into existing regulations.
A complete implementation approach will be developed in the project’s
next step. Two preliminary implementation concepts are described
below.
Adjust Existing Zoning
The most common approach is to simply add the new standards
into the existing zoning districts. This would be especially effective if
there were only citywide or district-based standards. This approach
would be less effective for implementation of standards that would
be applied differently depending on neighborhoods or areas.
Apply Using Zoning Overlays
Zoning overlays would be the ideal tool to apply standards based on
neighborhoods or other areas not defined by zoning district boundaries.
This tool could also be used to apply a general standard (such as
a maximum FAR) only to certain parts of the project area. While it
does add a level of complexity (some rules apply through underlying
zoning, which is then modified by the overlay), zoning overlays could
more effectively match the character of various areas.
Additional Tools
Regardless of the recommended strategy option that is chosen, a
number of additional tools are recommended including neighborhood
planning efforts and a voluntary design handbook as described
below.
Design Handbook
The city should develop a voluntary “handbook” for designing in the
single-family neighborhoods, which promotes consideration of scale
and character, while also encouraging creative design. This may
then serve as the basis for more finely-tailored, neighborhood based
guidelines that could be produced for selected areas.
Neighborhood Conservation Overlay
In addition to the zoning standards that are proposed in this strategy
report, the city should provide for an additional level of design
consideration that could be applied for specific neighborhoods that
may seek design review.
January 12, 2009 Page 69
Part 4: Recommended Strategy Strategy Report
Neighborhood Plans
The refined problem statement and recommended strategy options
reflect only those issues that have been identified with the character of
development in single-family neighborhoods. Neighborhood planning
efforts could be used to evaluate and address a number of related
problems and issues raised by the community including:
• Concern that existing regulations do not encourage sustainable
development patterns including increased densities or shops
and offices in close proximity to residences.
• Concern regarding the availability of affordable housing (often
related to the concern that existing regulations do not allow suf-
ficiently increased densities).
• A desire for neighborhood or area-specific standards or design
guidelines.
It is recommended that the city proceed to develop additional
neighborhood plans.
Recommended Regulatory Improvements
and Streamlining
Several general changes and additions are recommended regardless
of which specific tools are selected or how and where they are
implemented. Where feasible, existing regulations should be
simplified or streamlined so that they are easier to use and do not
create unnecessary barriers for homeowners or for architects and
builders who are engaged in compatible development projects in
single-family neighborhoods. Several general recommendations are
provided below.
Improve User-Friendliness
No matter which tools are applied or which approach to their
implementation is taken, it is worth considering some modest
changes to the city’s existing regulations in order to increase the
user-friendliness and clarity of the document. While the Modular
Zone System is analytically rigorous, it is not user-friendly. Having
to shift among the various chapters to find key elements of a given
zoning district is difficult – more so in these single-family districts,
which are typically the simplest of all zoning districts.
While a fundamental change is not required, some modest additions
and revisions could help improve access to information in the existing
code. Such revisions and additions would be especially important if
some combination of the recommended tools described in this report
are integrated into existing regulations.
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Strategy Report Part 4: Recommended Strategy
Add Table Headings
One simple idea is to improve the ease of use of the various key tables
in the Boulder Revised Code (BRC) (Table 6-1 Use Table and Table
7-1 Form and Bulk Standards) by including the applicable districts in
the table headings. For example, the R1 use requirements apply to
the RR-1, RR-2, RE and RL-1 districts. Instead of stating this only in
Table 5-1, why not include the affected districts in the heading?
Improve the Form and Bulk Standards Table
This table is difficult for the casual ordinance user to read. While
merging the columns that would display a similar number does reduce
the amount of text on the page, it makes determination of the rules
for any one district more confusing. Stating the numeric standard
in each column would ease this burden. And again, where the bulk
standards are separated by 50 intervening pages from the zoning
district key, perhaps the table heading could include the districts?
In addition, if possible, the form and bulk standards table would be
broken down into smaller pieces (two or more matrices). If possible,
a single matrix or series of matrices by district should be created to
implement the new standards. This substantially improves the ease
of use, in spite of the need for some duplication of material.
Include Additional Explanatory Graphics
The inclusion of additional graphics would assist with an understanding
of the intent for specific tools and would help illustrate how they are
defined and measured.
Provide Separate Zoning Summaries
In the past, the city has prepared separate summaries for each
zoning district. Resuming this practice would help residents access
and understand the code requirements that apply specifically to their
properties. Zoning district summaries could include user-friendly
illustrations and simplified tables.
Streamline Existing Regulations
Most communities administer and issue permits in single-family
residential neighborhoods through the building official, with no notice
to neighbors and no design review. Boulder’s system is currently
more complex, and many of the stakeholders commented on this
fact. Boulder may not be ready to handle all administration with no
notice and no design review, however, additional clarity may serve to
reduce the common friction between the developer and the neighbors.
Key elements for consideration include:
• Clear new definitions to match any new standards
• Use of smaller tables that are more directly related to a given dis-
trict (in place of the citywide matrices)
January 12, 2009 Page 71
Part 4: Recommended Strategy Strategy Report
Address Non-Standard Lots
Many communities require special processes or variances in order
to build on a lot that does not meet the zoning district’s minimum
size standard. If one assumes that existing lots should be used for
homes, then a more streamlined approach is appropriate.
Application of the recommended tools by lot size and zoning district
provides a framework to specify standards for all lots sizes including
those that are smaller than the existing minimum lot size standard.
For example, if the district minimum lot area is 7,000 SF, then the
standards might be provided in three categories that vary based on
lot area: under 6,000 SF, 6,000 to 8,000 SF, and above 8,000 SF
(more lot size categories may be appropriate for districts or groups
of districts with a greater range of existing lot sizes as shown in the
tables on pages 64 and 65). The standards can be calibrated based on
modeling these three conditions, yielding the correct results through
the standards themselves, without the need for special approvals.
Using this system, existing lots that are smaller than the minimum
standard need not be considered as non-standard lots for purposes
of additions and new construction. However, it is still possible to
maintain a minimum lot size standard (in our example 7,000 SF) for
subdivision purposes in order to ensure that new lots below a certain
size threshold are not created. This approach could eliminate most
non-standard lot conditions for purposes of development but would
not address existing non-standard building characteristics such as
buildings that exceed current height or setback limits.
Solar Ordinance
Revisions to the solar ordinance are not recommended as part of this
strategy. If the city does consider revisions to its solar ordinance, the
effects of any changes on building mass and scale should be included
in the process. It also may be useful to address the interaction of
building massing and the solar ordinance in the proposed Design
Handbook. This could be useful when there are requests for alternative
solutions under the solar ordinance review process.
Page 72 January 12, 2009