green building by DocKing007

VIEWS: 18 PAGES: 9

									GREEN
BUILDING
Abstract
Green building also known as green              Reducing waste, pollution and
construction or sustainable building             environmental degradation.
refers to a structure and using process
that is environmentally responsible       A similar concept is natural building,
and resource-efficient throughout a       which is usually on a smaller scale
building's life-cycle: from siting to     and tends to focus on the use of
design, construction, operation,          natural materials that are available
maintenance, renovation, and              locally. Other related topics include
demolition. This practice expands and     sustainable design and green
complements the classical building        architecture. Sustainability may be
design concerns of economy, utility,      defined as meeting the needs of
durability, and comfort.                  present generations without
                                          compromising the ability of future
Although new technologies are             generations to meet their needs. Green
constantly being developed to             building does not specifically address
complement current practices in           the issue of the retrofitting existing
creating greener structures, the          homes.
common objective is that green
buildings are designed to reduce the
overall impact of the built
environment on human health and the
natural environment by:

      Efficiently using energy, water,
       and other resources
      Protecting occupant health and
       improving             employee
       productivity
                                            Goals of green
Reducing                                    building
environmental
impact
Green building practices aim to
reduce the environmental impact of
buildings, and the very first rule is, do   a green building designed by Michelle
not build in sprawl (spreading in           Kaufmann.
disordered fashion). No matter how
much grass you put on your roof, no         The concept of sustainable
matter how many energy-efficient            development can be traced to the
windows, etc., you use, if you build in     energy (especially fossil oil) crisis and
sprawl, you've just defeated your           the environment pollution concern in
purpose. Buildings account for a large      the 1970s. The green building
amount of land. According to the            movement in the U.S. originated from
National Resources Inventory,               the need and desire for more energy
approximately 107 million acres             efficient and environmentally friendly
(430,000 km2) of land in the United         construction practices. There are a
States are developed. The                   number of motives to building green,
International Energy Agency released        including environmental, economic,
a publication that estimated that           and social benefits. However, modern
existing buildings are responsible for      sustainability initiatives call for an
more than 40% of the world’s total          integrated and synergistic design to
primary energy consumption and for          both new construction and in the
24% of global carbon dioxide                retrofitting of an existing structure.
emissions.                                  Also known as sustainable design,
                                            this approach integrates the building
                                            life-cycle with each green practice
                                            employed with a design-purpose to
create a synergy amongst the practices   one or more of these principles. Also,
used.                                    with the proper synergistic design,
                                         individual green building technologies
Green building brings together a vast    may work together to produce a
array of practices and techniques to     greater cumulative effect.
reduce and ultimately eliminate the
impacts of buildings on the              On the aesthetic side of green
environment and human health. It         architecture or sustainable design is
often emphasizes taking advantage of     the philosophy of designing a building
renewable resources, e.g., using         that is in harmony with the natural
sunlight through passive solar, active   features and resources surrounding
solar, and photovoltaic techniques and   the site. There are several key steps in
using plants and trees through green     designing sustainable buildings:
roofs, rain gardens, and for reduction   specify 'green' building materials from
of rainwater run-off. Many other         local sources, reduce loads, optimize
techniques, such as using packed         systems, and generate on-site
gravel or permeable concrete instead     renewable energy.
of conventional concrete or asphalt to
enhance replenishment of ground
water, are used as well.

While the practices, or technologies,
employed in green building are
constantly evolving and may differ
from region to region, there are
fundamental principles that persist
from which the method is derived:
Siting and Structure Design
Efficiency, Energy Efficiency, Water
Efficiency, Materials Efficiency,
Indoor Environmental Quality
Enhancement, Operations and
Maintenance Optimization, and Waste
and Toxics Reduction. The essence of
green building is an optimization of
Siting and
structure design                            Energy
efficiency                                  efficiency
The foundation of any construction
project is rooted in the concept and
design stages. The concept stage, in
fact, is one of the major steps in a
project life cycle, as it has the largest
impact on cost and performance. In
designing environmentally optimal
buildings, the objective is to minimize
the total environmental impact
                                               An eco-house at Findhorn Ecovillage with a
associated with all life-cycle stages of
                                            turf roof and solar panels
the building project. However,
building as a process is not as
streamlined as an industrial process,
and varies from one building to the         Green buildings often include
other, never repeating itself               measures to reduce energy
identically. In addition, buildings are     consumption – both the embodied
much more complex products,                 energy required to extract, process,
composed of a multitude of materials        transport and install building
and components each constituting            materials and operating energy to
various design variables to be decided      provide services such as heating and
at the design stage. A variation of         power for equipment.
every design variable may affect the
                                            As high-performance buildings use
environment during all the building's
                                            less operating energy, embodied
relevant life-cycle stages.
                                            energy has assumed much greater
                                            importance – and may make up as
                                            much as 30% of the overall life cycle
                                            energy consumption. Studies such as
the U.S. LCI Database Project show
buildings built primarily with wood        Water efficiency
will have a lower embodied energy
than those built primarily with brick,     Reducing water consumption and
concrete or steel.                         protecting water quality are key
                                           objectives in sustainable building.
To reduce operating energy use, high-      One critical issue of water
efficiency windows and insulation in       consumption is that in many areas, the
walls, ceilings, and floors increase the   demands on the supplying aquifer
efficiency of the building envelope,       exceed its ability to replenish itself.
(the barrier between conditioned and       To the maximum extent feasible,
unconditioned space). Another              facilities should increase their
strategy, passive solar building           dependence on water that is collected,
design, is often implemented in low-       used, purified, and reused on-site. The
energy homes. Designers orient             protection and conservation of water
windows and walls and place                throughout the life of a building may
awnings, porches, and trees to shade       be accomplished by designing for
windows and roofs during the summer        dual plumbing that recycles water in
while maximizing solar gain in the         toilet flushing. Waste-water may be
winter. In addition, effective window      minimized by utilizing water
placement can provide more natural         conserving fixtures such as ultra-low
light and lessen the need for electric     flush toilets and low-flow shower
lighting during the day. Solar water       heads. Bidets help eliminate the use of
heating further reduces energy costs.      toilet paper, reducing sewer traffic
                                           and increasing possibilities of re-
Onsite generation of renewable
                                           using water on-site. Point of use water
energy through solar power, wind
                                           treatment and heating improves both
power, hydro power, or biomass can
                                           water quality and energy efficiency
significantly reduce the environmental
                                           while reducing the amount of water in
impact of the building. Power
                                           circulation. The use of non-sewage
generation is generally the most
                                           and greywater for on-site use such as
expensive feature to add to a building.
                                           site-irrigation will minimize demands
                                           on the local aquifer.
Materials                                manufactured off-site and delivered to
                                         site, to maximise benefits of off-site

efficiency
                                         manufacture including minimising
                                         waste, maximising recycling (because
                                         manufacture is in one location), high
Building materials typically             quality elements, better OHS
considered to be 'green' include         management, less noise and dust.
lumber from forests that have been
certified to a third-party forest
standard, rapidly renewable plant        Operations and
materials like bamboo and straw,
dimension stone, recycled stone,         maintenance
recycled metal, and other products
that are non-toxic, reusable,            optimization
renewable, and/or recyclable (e.g.,
Trass, Linoleum, sheep wool, panels      No matter how sustainable a building
made from paper flakes, compressed       may have been in its design and
earth block, adobe, baked earth,         construction, it can only remain so if
rammed earth, clay, vermiculite, flax    it is operated responsibly and
linen, sisal, seagrass, cork, expanded   maintained properly. Ensuring
clay grains, coconut, wood fibre         operations and maintenance personnel
plates, calcium sand stone, concrete     are part of the project's planning and
(high and ultra high performance,        development process will help retain
roman self-healing concrete) , etc.)     the green criteria designed at the onset
The EPA (Environmental Protection        of the project. Every aspect of green
Agency) also suggests using recycled     building is integrated into the O&M
industrial goods, such as coal           phase of a building's life. The addition
combustion products, foundry sand,       of new green technologies also falls
and demolition debris in construction    on the O&M staff. Although the goal
projects. Building materials should be   of waste reduction may be applied
extracted and manufactured locally to    during the design, construction and
the building site to minimize the        demolition phases of a building's life-
energy embedded in their                 cycle, it is in the O&M phase that
transportation. Where possible,          green practices such as recycling and
building elements should be              air quality enhancement take place.
Waste reduction                            materials such as wood that are light
                                           and easy to work with make
                                           renovations easier.
Green architecture also seeks to
reduce waste of energy, water and          To reduce the impact on wells or
materials used during construction.        water treatment plants, several options
During the construction phase, one         exist. "Greywater", wastewater from
goal should be to reduce the amount        sources such as dishwashing or
of material going to landfills. Well-      washing machines, can be used for
designed buildings also help reduce        subsurface irrigation, or if treated, for
the amount of waste generated by the       non-potable purposes, e.g., to flush
occupants as well, by providing on-        toilets and wash cars. Rainwater
site solutions such as compost bins to     collectors are used for similar
reduce matter going to landfills.          purposes.

To reduce the amount of wood that          Centralized wastewater treatment
goes to landfill, the CO2 Neutral          systems can be costly and use a lot of
Alliance (a coalition of government,       energy. An alternative to this process
NGOs and the forest industry) created      is converting waste and wastewater
the website dontwastewood.com. The         into fertilizer, which avoids these
site includes a variety of resources for   costs and shows other benefits. By
regulators, municipalities, developers,    collecting human waste at the source
contractors, owner/operators and           and running it to a semi-centralized
individuals/homeowners looking for         biogas plant with other biological
information on wood recycling.             waste, liquid fertilizer can be
                                           produced. This concept was
When buildings reach the end of their      demonstrated by a settlement in
useful life, they are typically            Lubeck Germany in the late 1990s.
demolished and hauled to landfills.        Practices like these provide soil with
Deconstruction is a method of              organic nutrients and create carbon
harvesting what is commonly                sinks that remove carbon dioxide
considered “waste” and reclaiming it       from the atmosphere, offsetting
into useful building material.             greenhouse gas emission. Producing
Extending the useful life of a structure   artificial fertilizer is also more costly
also reduces waste – building              in energy than this process.
Cost and payoff                           Regulation and
The most criticized issue about           operation
constructing environmentally friendly
buildings is the price. Photo-voltaics,   As a result of the increased interest in
new appliances, and modern                green building concepts and practices,
technologies tend to cost more            a number of organizations have
money. Most green buildings cost a        developed standards, codes and rating
premium of <2%, but yield 10 times        systems that let government
as much over the entire life of the       regulators, building professionals and
building. The stigma is between the       consumers embrace green building
knowledge of up-front cost vs life-       with confidence. In some cases, codes
cycle cost. The savings in money          are written so local governments can
come from more efficient use of           adopt them as bylaws to reduce the
utilities which result in decreased       local environmental impact of
energy bills. Also, higher worker or      buildings.
student productivity can be factored
into savings and cost deductions.         Green building rating systems such as
                                          BREEAM (United Kingdom), LEED
Confirming the rentability of green       (United States and Canada), help
building investments, further studies     consumers determine a structure’s
of the commercial real estate market      level of environmental performance.
have found that LEED and Energy           They award credits for optional
Star certified buildings achieve          building features that support green
significantly higher rents, sale prices   design in categories such as location
and occupancy rates as well as lower      and maintenance of building site,
capitalization rates potentially          conservation of water, energy, and
reflecting lower investment risk.         building materials, and occupant
                                          comfort and health. The number of
                                          credits generally determines the level
                                          of achievement.

								
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