Green Laws Green Laws • ti
& Community e
LSU Green Laws Research Project
Design Daniel Raggio
Louisiana Department of Agriculture & Forestry
EBR Parish Tree And Landscape Commission Photographs: Live Oak Gardens
Abbey Associates Landscape
Community Landscape Codes
Landscape codes or green laws are special parts of a
community’s zoning ordinance. Certain provisions are written
to influence the design of parking facilities and make
improvements to the environment of urban areas
Notable codes include New York City, Gainesville, Florida,
Cary, North Carolina, Davis, California, Portland, Oregon,
Charleston, South Carolina, Austin, Texas,
New Holland, Illinois, Dublin, Ohio
Gross Ile Township, Michigan
and Mandeville, Louisiana require improvements
to parking lot environments.
Open Space Planting Requirements
Most codes require a specified amount of open space for the purpose
of planting trees or allowing permeable space to soak up storm water
or trap sediments. Open space planting is often measured by canopy
coverage or by DBH measure. DBH measure equates to the quantity
of trees on a site.
The Problem 1.
The Problem 2.
The Problem 3.
The Problem 4.
Purpose of Open Space
Re-establish the urban forest following development
Require a specified amount of open space for the
purpose of planting trees or allowing permeable space to
soak up storm water or trap sediments
Determine that an appropriate percentage of the site
remain “permeable” and plantable
Types of Requirements
Lot sizes reduced but must be compensated by an
equivalent area as open space.
At least 40 percent of the subdivision must be provided
as open space to obtain a density of 2.3 units per net
The minimum size of such active recreation space shall
be the number of square feet derived by multiplying
gross land area by the applicable ratio
Code Writing Essentials
Open space for planting trees or for permeable space to soak up water
On development site, access to amenities
length, width, height, acreage, lot size
Relation to existing lot size or development
native, deciduous, evergreen, spacing, growth rate, existing
Recreation, open space, permeability,
of Open Space
Visual Gallery 1.
Green space along riverfront
– Chattanooga, TN
Visual Gallery 2.
Planting along road and walkway – Chattanooga, TN
Visual Gallery 3.
Open space percentage – Cincinnati, OH
Visual Gallery 4.
Tree canopy density – Louisville, KY
Visual Gallery 5.
Open space along roadside – Memphis, TN
Visual Gallery 6.
Minimum open space (aquarium) – Chattanooga, TN
Aesculus (Buckeye) Specimen Trees
Amelanchier (Serviceberry) South Carolina
Typical Code Specs
City of Gwinnett
One (1) tree for each 25 linear feet of strip length shall be
provided. Deciduous trees shall be at least 2 inches in diameter
and evergreen trees shall be 6 feet in height at time of planting.
Trees shall be a species native or suitable to this region.
On each property for which a Tree Preservation and/or
Replacement Plan is required, existing trees shall be retained
and/or new trees shall be planted such that the property shall
attain or exceed a Tree Density Standard of 16 Tree Density Units
per acre, exclusive of any acreage within a zoning buffer and any
trees required to be preserved or planted within a zoning buffer
and except any other land area allowed to be excluded by this
Typical Code Specs
City of Chapel Hill
Required buffers shall be located along the interior or street lot
lines nearest the adjacent streets, land uses, or zoning
designations except where such lot lines are intersected by
crossing accessways or utility easements, or by a joint parking
area. Buffers shall not be located on any portion of an existing or
proposed street right-of-way or easement.
No tree greater than six (6) inches in diameter at breast height
(DBH) shall be removed for the purpose of surveying without a
permit issued by the town manager approving such action.
Typical Code Specs
City of Charleston
One canopy tree shall be provided for each 50 linear feet of
parking, loading or vehicular use area perimeter. These trees may
be used to satisfy the interior parking lot landscaping
All trees with a diameter breast height (DB(h) of 6 inches or
greater within buffers shall be preserved.
Paved areas shall not constitute more than 25 percent of the
protected area beneath a tree. Any paving, grading, trenching, or
filling within the remaining 75 percent of the protected area must
be approved by the Planning Director and may require specific
construction techniques be used in order to preserve the health of
City of Gwinnett, Georgia Land Use Management, Appendix A,
Article 5.6, Landscaping Screening and Buffering
City of Charleston, South Carolina Development Standards,
Appendix A, Zoning and Land Development Regulations, Article 9.5,
Landscaping Screening and Buffering
City of Chapel Hill, North Carolina Land Use Management
Appendix A, Design and Development Standards, Article 5