The following is a list of a few of the "green" features and building practices promoted in the Built Green® program:
Energy Efficiency
Indoor Air Quality
Conserving Natural Resources
Water Quality
Energy Efficiency
Advanced Framing/Extra Insulation Advanced
framing is a technique used by builders help reduce construction costs
and increase energy savings. On average, advanced framing uses 30% less
lumber, takes less time to construct, and costs less to build because
the reduced use of lumber more than offsets the additional cost of
extra insulation. Construction cost savings is estimated at $0.29 per
square foot of wall area. Total savings for this measure alone are 2 to
4% of total energy use.
High Efficiency Water Heater Locating
the hot water heater near the point of highest use will minimize
pipeline energy loss. Typically, the point of highest demand is the
shower. Another strategy designed to increase efficiency is to insulate
hot and cold water pipes within 3 feet of the hot water heater. This
measure reduces standby heat loss from the water tank. The tank
continuously heats the piping and the water in it even when no water is
being used. The pipes act as "cooling rods." Insulating them reduces
the rate of heat loss. In addition, choosing a high efficiency water
heater can save energy and water.
Efficient Household Appliances Built
Green homes feature appliances that are as energy efficient as
possible. The reduced costs associated with operating energy efficient
appliances offset any higher initial costs of purchasing the
appliances. Builders are encouraged to use appliances that have "Energy
Guide" or Energy Star® labels to insure that they meet energy efficient
criteria.
Air Sealing Advanced
caulking is part of the airtight drywall approach (ADA) for framed
structures, which is an advanced sealing package that goes beyond basic
practice. Specifically, caulk or gasket drywall is installed on
exterior walls at the top and bottom plates, windows and doorframes.
Caulk or gasket drywall is used on interior walls at intersections with
exterior ceilings. Caulk or gasket drywall is used at electrical,
plumbing or mechanical penetrations in the drywall.
Indoor Air Quality
Carpet Using
low-pile or less allergen-attracting carpet and pad can greatly improve
indoor air quality. Installing carpeting by tacking rather than using
glue also reduces air pollutants. There are also natural fiber carpets
available such as jute, sisal and wool that many builders offer to
improve air quality. Many Built Green homes feature plans that reduce
the amount of carpeting and use alternate flooring made from
sustainably harvested wood or bamboo.
Paints Many Built
Green® homes use low-VOC and low-toxic interior paints and finishes to
reduce toxins ordinarily associated with other paints. Using these
types of paints helps to improve the overall indoor air quality of the
home.
Ventilation
Greater air tightness creates a need for mechanical ventilation to
avoid potential indoor air quality problems. Balanced or slightly
positive ventilation keeps outdoor pollutants from being drawn into the
house, prevents backdrafting or spillage from combustion appliances
(due to under-pressurization), and prevents moisture migration into
structural cavities (due to over-pressurization). Ventilation can be
provided by quiet fans with automatic controls or by heat recovery
ventilators. In a balanced system, air brought indoors by one fan is
exhausted outdoors at the same rate by another fan. In a slightly
positive system, air brought indoors is exhausted outdoors at a
slightly slower rate. It is important to avoid over-pressurizing the
building, which will force moisture into and through walls and other
structural cavities. To get a slightly positive air pressure you must
adjust supply ventilation slightly higher than exhaust ventilation (if
exhaust is provided). If you are not sure you can maintain a slightly
positive pressure without over-pressurizing the building, it is best to
seek a balanced pressurization.
Conserving Natural Resources
Plastic Lumber
There
are many manufacturers of plastic lumber nationwide. Recycled plastic
lumber or plastic/wood composite lumber provide durable alternatives to
solid wood for exterior applications such as fences, benches, decking,
docks, retaining walls, picnic tables, and landscape borders. Due to
its weather-and insect-resistant nature, plastic lumber can readily
substitute for treated wood in non-structural applications. Plastic
lumber is also rot and corrosion-proof, and will not crack, splinter,
or chip. It has a long life expectancy in exposed, sub-grade or marine
applications, and does not leach chemicals into ground or surface water
or soil as treated wood can.
Plastic lumber resists vandalism and does not require painting. It
is available in a variety of colors,including white, although many
companies have a standard color of either brown or black. These
products can be nailed, screwed, sanded, glued, or turned on a lathe
with standard woodworking tools. One challenging aspect of working with
plastic lumber is its high expansion coefficient, which must be
considered during installation. Check with the manufacturer regarding
structural support specifications.
Engineered Wood There
is a large family of engineered structural products, including
laminated veneer lumber (LVL), wood I-beams and I-joists, and wood roof
and floor trusses. These products combine efficient raw material use
with improved strength and performance capabilities to produce a
superior option to traditional materials. Engineered lumber
manufacturers use fast-growing, small-diameter trees efficiently.
Combining wood veneer and fiber with adhesives produces laminated
veneer lumber. The LVL manufacturing process allows more of the log (up
to 80%) to end up as product. LVL lumber is very consistent and stable.
Wood I-beams and I-joists also combine veneer and adhesives.
LVL headers and I-beams are accepted by all major building codes.
They provide more load-bearing capacity than solid sawn lumber, and
resist shrinking, twisting, splitting, warping, and crowning. They are
capable of long spans, thereby increasing design flexibility. They can
cost more than dimensional lumber, but in general are considered better
products. The American Plywood Association estimated that in 1998
I-joists alone accounted for over a third of all residential floor
joists installed in the U.S. Wood roof and floor trusses are commonly
used instead of cut rafters because they save both time and materials.
They can also reduce wood waste because, ideally, you order only what
you need, and because of efficiencies in the production process.
Fiber Cement Siding Fiber-cement
composites are resource-efficient, and in addition to durability and
low maintenance, offer a very good fire rating when compared to wood or
metal siding. The wood fiber in these products is reclaimed from wood
processing waste. It can also be harvested from small diameter
fast-growing species.
Minimizing the need to replace any siding product offers a maximum
consumer benefit to the homeowner, in addition to the obvious
environmental impact. Many of the fiber-cement composites offer a
50-year warranty.
Brick The process
of extracting clay for brick production is fairly benign, and results
in very little wasted material. Brick is often used close to its
manufacturing site. It has an almost limitless life-span and can be
recycled or salvaged for use after demolition. Brick is also a
recyclable material that can be crushed and either returned to the
manufacturing process, or used as a landscaping material in its crushed
form.
Building Materials and Food Recycling Built
Green® builders and remodelers recycle as much as possible of scrap
building materials and post a jobsite recycling plan to decrease the
amount of materials going to our already overburdened landfills.
Building materials such as lumber, wall board, concrete, cardboard,
ceiling tiles, paints and packaging can often be recycled. If a
remodeler or builder is deconstructing an existing building on the
site, many of those materials can also be salvaged or recycled
including wood flooring, framing materials, brick, ceramic tile and
stone, trim and cabinetry, among others. Our builders also facilitate
homeowner recycling by installing recycling bins in kitchens or
garages. Also, food recycling chutes are an alternative to traditional
food garbage disposals that many builders include to provide homeowners
with an easy way to compost food waste.
Water Quality Protection
Porous Paving Schemes
The goal of this strategy is to reduce or eliminate runoff due to
impervious (watertight) surfaces. Minimizing or eliminating impervious
surfaces by designing driveways, walkways, and patios that allow
stormwater runoff to infiltrate into the ground minimizes the impact on
aquatic systems. Uncompacted gravel, crushed stone and open or porous
paving blocks can be used for walkways and other light traffic areas.
Rainwater Collection Rainwater
collected from the roof is a free source of landscape irrigation water.
These systems can reduce outdoor water usage, thereby reducing the
homeowner's water consumption. Rainwater can also be harvested from
soil surfaces and outdoor paved surfaces. These systems are designed to
provide water for irrigation and are not intended for potable
(drinking) use. A rooftop rainwater collection system consists of a
suitable roof and guttering system, a storage tank(s), and a simple
filtration system. Cistern or tank storage is sized for the rainfall
amount and roof size, with appropriate overflow devices. Cisterns can
be made of concrete, ferro-cement, stone, or prefabricated metal,
plastic, or fiberglass and use only watertight, opaque materials.
Low Impact Development Low
Impact Development (LID) is an innovative approach to stormwater
management that uses nature as its model, and in the process can help
protect streams, fish and wildlife habitat, wetlands, shellfish growing
areas, and drinking water supplies. Basically, LID's goal is to mimic a
site's predevelopment hydrology by using design techniques that
infiltrate, filter, store, evaporate, and detain rainwater runoff close
to its source. Instead of disposing and treating stormwater in large,
costly end-of-pipe facilities located at the bottom of drainage areas,
LID addresses stormwater through small, cost-effective landscape
features located at the lot level. LID features can include many
components of the urban environment such as open space, vegetated
rooftops, reduced street widths and curbs, streetscapes, pervious
parking lots and sidewalks, medians and other buffer zones using more
vegetation. These LID practices can potentially increase developable
land for large or small developers by reducing size requirements for
stormwater ponds, and also lower infrastructure costs. LID can be
applied to new development, urban retrofits, and redevelopment projects