Environmental Benefits
 I. Understanding the Basis of Our Environment and Buildings
To understand the environmental benefits of the features of a Built Green
home, it is necessary to first have a platform from which to understand current
environmental issues and how they relate to buildings, and the home you live in.
It is helpful to start by understanding the three general environmental concerns
that should be considered in every green building; energy efficiency, resource
conservation, indoor air quality.
1) Energy Efficiency Benefits
- Cost savings
- Comfort
- Reduced pollution
The benefits of using energy wisely have been touted for years, particularly
since the energy crisis of the 70s. But we have grown complacent by the
relatively low costs of energy over the last decade. Up until fairly recently,
we paid our utility bill without much scrutiny. Now, however, with energy prices
rising, energy costs take a noticeable piece of the budget, so energy efficiency
makes clear economic sense. It's certain that energy prices will rise above
current levels, so an energy-efficient home is going to be an asset in the
coming years.
And it goes without saying that everyone wants a home that stays warm in the
winter and cool in the summer, without drafts, cold rooms, or hot spots - that
is, we all want to be comfortable.
It is important to note, however, that beyond comfort and the impact on our
pocket books, the energy consumption of a building over its useful life is its
single most significant environmental impact. A building constructed today will
use a lot on energy over its average life of 30 to 50 years, and that use has
many implications.
The growing brown cloud over the Front Range is in part a result of how much
energy we use in our homes. Electricity generated by coal-burning power plants
results in emissions of carbon dioxide, sulfur dioxide and nitrous oxides.
Natural gas fired electricity generation also contributes significant amounts of
carbon dioxide to our air. Reducing the average house's energy use by 30% will
reduce carbon dioxide emissions by about 34,000 pounds over its 30-year
lifetime.
US petroleum reserves are already in decline and known world reserves will be
in decline by 2010-2020. The world will probably never completely run out of
oil, but as reserves decline, only those reserves that are the most difficult and
expensive to tap, and more hazardous to the local habitats, will remain. Because
of extraction cost, air quality and environmental concerns, it is likely that
oil will become too expensive to burn for heat or electricity.
So energy efficiency is only common sense. Save money, be comfortable, and
protect the environment. A well-insulated, well-sealed home with efficient
windows, appliances, lighting and equipment is an absolute basic in green
building. Incorporating passive solar design and solar water heating is cost
effective and a prudent investment to reduce exposure to future energy cost
increases. And all energy efficiency measures are vital to protecting our
environment.
2) Resource Conservation Benefits
- Better use of our natural resources
The benefits of resource conservation are sometimes hard to convey on a
personal level when talking about buying a home. Certainly we can all understand
our stewardship responsibilities on the more global, impersonal level, but
should a consciousness of that responsibility be a part of our home buying
decision?
Resource conservation is many things. Perhaps you enjoy camping or hunting,
and know the personal value you place on the opportunity to visit natural,
undisturbed areas with their wide varieties of wildlife. Or maybe you fish, and
know how important clean, free running waters are to abundant, healthy fish
populations. Or you've heard about rapid destruction of the rainforests, and the
alarming loss of many animal and plant species in tropical regions. Or you've
seen the rampant growth of your local landfill gobbling up what used to be open,
clean land. These are just a few of the ways to think about what resource
conservation means as you think about what goes into building and operating your
home.
For example, engineered lumber products are an innovative alternative to the
solid sawn lumber materials that have to be harvested in diminishing old growth
forests. Twenty years ago the average tree harvested from our National Forests
was 24" in diameter. Today the average is 13". We have depleted the
resource. Forest products companies have responded to the situation by
developing engineered products to utilize fast growing farm trees to supplant
the reduced harvest from old forests. These products are stronger, straighter
and lighter, while using less wood fiber to perform the same structural
functions as solid sawn lumber. Fast growing tree farms are an example of a
renewable resource in our lifetime.
The use of recycled content building materials has grown out of the
increasing stockpiles of recycled material - materials that would otherwise
further burden our landfills. Today, Americans recycle 7 times more than they
did a decade ago. Building materials are the perfect application for recycled
refuse. Not only does recycling divert waste from the landfill, but also many of
the remanufactured materials are of higher quality and durability than
conventional materials.
Water is key to all life, and a resource that with a little planning we can
easily conserve. Water will be the gold of the 21st Century in Colorado. Given
current growth rates, water availability for the next century is in serious
question. The population on the Front Range is expected to double in the next 25
years, causing water supplies to be stressed. There are many options available
today to help conserve water inside the home and in our landscaping that will
help ensure that ample water will be available to serve the needs of those to
come.
3) Indoor Air Quality
The EPA reports that air in new homes can be 10 times more polluted than
outdoor air. Many products are manufactured with formaldehyde, a suspected human
carcinogen. Cabinets, counter tops, shelving and furniture are made from
particleboard that is glued together with formaldehyde that is released into the
home for years. Paints and floor finishes also contain chemicals that are not
healthy to breathe. That "new house smell" is actually the odor of
volatile organic compounds (VOCs) and is a telltale sign that there are harmful
chemicals in the indoor environment.
The construction industry has watched the evolution of these indoor air
problems and in response has developed alternate products to remedy the
conventional indoor toxicity situation. For example, not only do solvent-free
adhesives eliminate many of the suspected and known human carcinogens, but they
also adhere better. Paints that are free of volatile organic compounds are
commonly available. New construction materials such as OSB and Medite that
contain no formaldehyde are entering the market.
Providing good ventilation is also key to good indoor air quality. A number
of techniques and products are available to provide an exchange of fresh air,
isolation of combustion by-products, and the active ventilation of moisture and
other indoor pollutants.
II. Immediate Benefits of Green Features
Most of the features listed in the Built Green Checklist have an overall
environmental benefit addressing one or more of the three areas of environmental
concern above. There are many other, more immediate benefits that accrue to the
homeowner. These include:
- Lower monthly costs
- Improved resale
- Greater comfort
- Quieter
- Improved Indoor Air Quality
- Greater safety
- Greater Durability
- Less maintenance
III. The Checklist
The Built Green Checklist is broken down by Building Category. In the outline
below the environmental concerns pertinent to each Building Category are
addressed at the beginning of each section, followed by features and benefits.
It is important to note that each environmental feature in the checklist is
related to the three major areas outlined above: Energy Efficiency, Resource
Conservation and Indoor Air Quality. Some features address concerns in two or
three of the areas.
Category II LAND USE: LOT
a) Environmental Concerns
Trees can be damaged during construction from compacting the root system, and
may die as much as a year later from such damage. Topsoil is one of the world's
most rapidly vanishing resources. It is our richest, most valuable, yet thinnest
layer of soil; scraped off during construction, it is costly to replace later
for landscaping.
b) Features
- Trees and natural features on site protected during construction.
- Save and reuse all site topsoil
- Home orientation encourages solar heating and reduces overheating
potential of west-facing glass
- Home oriented on lot within 30 degrees of solar south
c) Benefits
- Trees and natural features on site have been protected during
construction.
Mature trees help shade the home in summer keeping it cooler and more
comfortable. Trees on the north and west side provide a windscreen in the
winter keeping the house warmer.
- Topsoil will be saved and reused.
It saves money by not having to bring in as much new soil for
landscaping and lawns. Topsoil is the most valuable soil for landscaping and
gardening your yard.
- Home orientation encourages solar heating and reduces overheating
potential of west-facing glass.
The right orientation can create year-round comfort. Huge expanses of
west-facing glass will create comfort problems and mandate the extra expense
of air conditioning.
Category III WASTE MANAGEMENT
a) Environmental Concerns
Americans today generate over 4 pounds of household waste per person per day;
only 17% of that gets recycled. Waste generated goes to increasingly crowded
landfills and some waste virtually never breaks down. Typical new construction
creates literally tons of debris. Home construction can produce up to 5 tons of
waste per house. Job site wastes include metals, wood and cardboard, which
represent over 50% of the debris normally taken to landfills.
b) Features
- Built-in kitchen recycling center to include two or more bins
- Minimize job site waste by using materials wisely
- Prohibit burying construction waste
- Recycle job site waste (>50%)
- Short-term compost storage bins (not on the Checklist)
c) Benefits
- Provide a built-in kitchen recycling center to include two bins
Today Americans recycle 7 times more waste that we did IO years ago.
Built in bins make it as easy for you as possible to manage the recycling
efforts.
- Job site waste is minimized by using materials wisely and prohibit the
burying of construction debris
- Job site waste is recycled
Using materials effectively increases the value of the home. Recycled
waste diverts trash from the waste stream and is used converted into new,
usable materials.
- Short-term compost storage bins
(not on Checklist)
Composting reduces the waste hauled to the landfill. Compost, turned to
soil, is great for gardens.
Category IV ENERGY USE: ENVELOPE
a) Environmental Concerns
The envelope of the house is the greatest source of heat loss, causing
uncomfortable indoor temperatures. Air infiltration in our windy climate is a
major culprit of heat loss. Inefficient windows contribute to temperature
swings, resulting in higher energy use to keep the house comfortable all year
round.
b) Features
- South glass area is between 5-7% of total finished floor
- Advanced sealing package
- Provide south roof area for future solar collector use
- Home designed for passive solar heating
- Energy heels of 6" on trusses
- Two-foot overhang, between one and two feet above south windows
- Blower door test with 0.35 ACH or less
- House is wrapped with an exterior air infiltration barrier
- Sill plate sealed with foam sill gasket
- House meets the EPA Energy Star Program criteria
- Insulated headers, minimum R-10
c) Benefits
- South glass area is between 5-7% of total finished floor area
By sun tempering the home, the south facing windows reduce heating
requirements by 10-20%, lowering the utility bills.
- Advanced sealing has been performed on the house
Foaming and caulking the areas of potential infiltration reduces drafts
and makes the home more comfortable in winter.
- Blower door testing has shown that the air infiltration rate of the
home is less than 0.35 air changes per hour (ACH)
Houses breathe by exchanging outdoor air with indoor air through cracks
and penetrations in the envelope. The less air exchange there is, the more
energy efficient the home. The blower door test determines how much heat the
house loses through infiltration. Below 0.35ACH requires makeup air or
ventilation to provide fresh air.
- Sill plate sealed with foam sill gasket
One of the primary sources for air leaks and comfort problems can be
eliminated with a foam sill gasket.
- Insulated headers, minimum R-10
This feature helps reduce heat loss while replacing solid lumber with
more resource-efficient engineered lumber.
Category V ENERGY USE: MECHANICAL Systems
a) Environmental Concerns
Often in new construction, mechanical systems are an afterthought. Design and
installation of mechanical systems often leads to unwanted heat loss through
poorly designed or uninsulated, unsealed ductwork. Too many mechanical systems
are oversized, resulting in frequent cycling which lowers unit efficiency.
b) Features
- Furnace centrally located
- No ducts in outside walls unless ducts are insulated to R-6 and sealed
with mastic
- No ductwork in attic unless ducts are insulated to R-6 and sealed with
mastic
- 87% or higher efficiency boiler
- 90%+ energy efficiency furnace
- Thermostat with "fan only" switch
- Two properly supported ceiling fan pre-wires
- Sealed-combustion gas or wood-burning fireplace or stove
- Setback thermostat
- Ductwork sealed with low toxic mastic
- Whole house fan installed
- Return-air ducts in every bedroom
- Active solar heating system
- Two or more thermostats controlling separate zones from a single heating
and/or cooling system
- Geothermal heating and/or cooling system
- In-floor heating system, slab insulated (if applicable) underneath and
edge
c) Benefits
- Furnace is centrally located
When the furnace is far away from where you want heat, especially in the
owner suite, the air is cooled by the time it reaches you and comfort is
compromised. A centrally located furnace leads to greater comfort in the
winter. Shorter duct runs save initial costs.
- Thermostat features an "fan only" switch for furnace fan to
circulate air
We live in a climate that doesn't require air conditioning very often.
During most of the spring, summer and fall just moving air can keep us
comfortable. The fan switch allows you to circulate air on the warmest days
making the house more comfortable without air conditioning.
- Sealed combustion gas Fireplace or sealed wood-burning fireplace or
stove with outside combustion air
Sealed combustion means that the air needed for the flame comes from the
outside directly. Otherwise you would be competing for oxygen with the
burning process. Sealing the fireplace is necessary to keep heat in. If
unsealed, the fireplace requires 2-3 times more energy than it provides to
the home simply by exhausting heat from the house up the chimney. Gas
fireplaces also reduce outdoor air pollution.
- Set back programmable thermostat
You want the house warmer when you are lounging in the evening or on
weekends than at night when you sleep. By letting the electronics remember
for you, it automatically saves energy.
- Furnace ductwork joints sealed with low toxic mastic
Ducts lose air at each joint like a hole in a bucket. Duct tape dries
out in a few years and loses its sealing ability. Mastic stays flexible for
much longer, assuring that heat gets to where it is supposed to go. Sealed
ducts are also safer, reducing the potential for combustion gasses to enter
the living space.
- Whole house fan installed
A whole house fan is much more energy efficient than air conditioning.
Comfort is maintained in our climate by drawing outside air in during all
but the most unusually hot days.
- Two or more thermostats controlling separate zones from a single
heating and/or cooling system
Controlling individual rooms or zones independently can save energy by
not keeping the entire house at the same temperature throughout the day, and
can add flexibility to individual comfort needs.
- Active solar heating system
Active solar heating systems may be justified if all other strategies
have been employed to reduce the need for added mechanical heating.
- Geothermal heating and/or cooling system
Geothermal systems use the earth's stable temperatures to provide
heating and cooling at very high efficiencies.
- In-floor heating system, slab insulated (if applicable) underneath and
edge
In-floor radiant heating is a comfortable (warm floors) and efficient
alternative to forced air systems. Floor insulation is critical to efficient
operation.
Category VI ENERGY USE: INDOOR AIR QUALITY
a) Environmental Concerns
Indoor air quality can be compromised in several ways: by carbon monoxide
escaping from furnaces and hot water heaters; by car exhaust containing toxic
chemicals entering into the house from attached garages; by off gassing from
building materials, furniture, fabrics; by unburned hydrocarbons resulting from
cooking; and the stir of dust inside the house.
b) Features
- Sealed-combustion furnace
- Sealed-combustion domestic water heater
- Exhaust fan in garage
- Heat recovery ventilator or air-to-air heat exchanger
- Radon mitigation installed to EPA guidelines
- Mechanical room enclosed and insulated to R-11
- Provide range hood vented to outside
- Furnace and/or duct-mounted electronic air cleaner or HEPA filter
- House meets the American Lung Association's Health House standards
c) Benefits
- Sealed-combustion furnace
- Sealed-combustion hot water heater
Carbon monoxide, a by-product of combustion, is a potential source of
indoor air problems. By isolating the combustion gases, they will not
migrate into the living space. Sealed units also eliminate the need for cold
make-up air ducts in the basement.
- Radon mitigation to EPA guidelines
If radon is detected in the home, this system will discharge the gases
safely, and can be modified to add a fan if necessary.
- All range hoods are vented to the outside
Unburned hydrocarbons can result from cooking. More than smells, these
particles are not healthy to breathe. Range hoods vent directly outside to
eliminate exposure to hydrocarbons, over heating and excess moisture
build-up.
Category VII ENERGY USE: WATER HEATING
a) Environmental Concerns
Water heating impacts both water consumption and
energy use. Heat is lost from hot water pipes as the water travels from the tank to the
shower or sink. If it is a long distance, water is wasted while waiting for the
water to warm up at the faucet or showerhead. Inefficient hot water heaters use
fuel that could be offset by solar energy.
b) Features
- Gas DHW with an energy factor of 0.60 or greater
- Insulate hot water pipes to R-6 in unconditioned spaces
- Water heater within 20 pipe feet of dishwasher and clothes washer
- Insulate all hot water lines to all locations
- Rough-in for future solar hot water
- Gas water heater with insulating blanket installed
- Insulate hot and cold water pipes 3 feet from the hot water heater
- Solar water heating system
- Geothermal water heating system
- Side-arm water heater off of efficient (87% or higher) boiler
c) Benefits
- Gas water heater has an energy factor of 0.60 or greater
New hot water heater technology allows us to install improved energy
efficient hot water heaters for a small additional cost. Efficient heaters
save you money every month as long as you own the home.
- Hot water pipes are insulated to R-6 in unconditioned spaces
By keeping water hot 24 hours a day, some heat is lost all the time.
Insulating the pipes reduces the heat loss and helps provide hot water
faster in far away sinks and showers.
- Solar water heating system
Solar water heating reduces energy use every day, and is cheaper than
heating water with electricity the day it is installed.
Category VIII ENERGY USE: APPLIANCES
a) Environmental Concerns
Appliances use electricity and water with varying degrees of efficiency. Some
refrigerators today can use twice the energy as others. Electric heating and
cooking is inefficient compared to gas or solar. Every kilowatt-hour (kwh) used
adds over 2 pounds of C02 (coal generated electricity) to the atmosphere, the
largest contributor to global warming.
b) Features
- Dishwasher has energy saving cycle or qualifies for Energy Star
- Gas clothes dryer with electronic ignition
- Gas range, cook top and/or oven with electronic ignition
- Refrigerator qualifies for Energy Star or has an annual electric cost less
than $66
- If appliances are not included, a list of energy efficient appliances is
provided
- Provide gas rough-in for clothes dryer, range, cooktop and/or oven when
those appliances not included with the home
- Solar electric system provides 20% or more of the home's electricity
c) Benefits
- A list of energy efficient appliances is provided
Energy efficient appliances can save from $50 - $200 per year in
electricity bills. Energy saving features in dishwashers save not only
electricity but reduce water consumption as well.
- Solar electric system provides 20% or more of the home's electricity
Solar electric (Photovoltaics or PVs) is becoming more cost-effective,
and can be a dependable back-up system for home office computers.
Category IX ENERGY USE: LIGHTING
a) Environmental Concerns
Incandescent light bulbs are an inefficient means of generating light. They
use 4 times more electricity than compact fluorescent bulbs. Dark houses that do
not receive much natural light through windows cost more to light and are less
pleasant for the inhabitants.
b) Features
- Light-colored walls and ceiling
- Light-colored carpet
- Furnish four compact fluorescent light bulbs to owners
- Extended-life incandescent bulb
- No can lights in insulated ceiling or Insulation Contact-Rated (IC Rated)
can lights are used
- Air tight can lights are used
- Solar-powered walkway or outdoor area lighting
c) Benefits
- Light colored interiors
Natural light makes people happier and healthier. With good placement of
windows and by keeping surfaces light colored, the need for daytime electric
lighting is reduced.
- No recessed lighting fixtures installed in insulated ceilings or
Insulation Contact-Rated (IC Rated) fixtures are used
Because of the heat build-up inside the typical recessed light fixtures,
units must be spaced away from the insulation in ceilings. The result of
that space is like keeping a window open all winter long. Special insulated
fixtures prevent the drafty effect of the recessed design.
- Air tight can lights are used
Can lights are some of the worst offenders related to air leaks in the
home. Airtight fixtures improve comfort and reduce energy bills.
- Solar-powered walkway or outdoor area lighting
Solar electric outdoor lighting visibly helps market the environmentally
friendly features of a Built Green home.
CATEGORY X MATERIALS: STRUCTURAL FRAME
a) Environmental Concerns
Engineered wood products alleviate problems associated with harvesting large
trees, the sources for which are diminishing because harvesting is outpacing
growth cycles. Outdoor structures like decks often use wood preserved with toxic
chemicals that can be easily avoided.
b) Features
- Large dimension solid lumber (2xlO or greater) avoided in floors and roofs
- Dimensional lumber from 3rd party certified sustainably harvested sources
- Engineered wood " I " joists used for floors
- Trusses or " I" joists used for roofs
- Structural insulated panels used for walls or roofs
- Reinforced cementitious foam-formed walls (ICFs, or insulated concrete
forms) using flyash concrete when temperature permits
- Engineered lumber products for beams and joists
- Engineered lumber products for window or door headers
- Reduced framing package (24" O.C. interior non-bearing walls; 3-stud
corners)
- Finger-jointed plate material
- Finger-jointed studs or engineered stud material
- Engineered alternatives to wood framing
- Outdoor structures, decking and landscaping materials made from:
- Pressure-treated engineered lumber
- Recycled materials
- Sustainably harvested lumber
- Recycled gypsum wallboard
c) Benefits
- Trusses or "I" joists are used for roofs
Engineered wood "I" joists are now cost competitive for most
applications and use fast growing farm trees for cellulose fiber and can use
most of the potential fiber. Engineered lumber products often use fast
growing farm trees that require 50% less wood fiber to perform the same
structural functions - better. Using I-joists results in a stronger home
with straighter walls, floors and ceilings.
- The house has been built with reduced framing
Reduced framing gets the maximum strength from the frame while
accommodating insulation in places that have conventionally been sources of
heat loss, such as comers and wall intersections. It also saves you money in
framing costs.
- Outdoor structures, decking and landscaping materials are made from
recycled materials or pressure-treated engineered lumber
Recycled content outdoor materials can be more durable than treated
solid lumber. Some will last for decades without painting or staining.
Pressure treated engineered lumber also saves large trees.
Category XI MATERIALS: FOUNDATION
a) Environmental Concerns
Forming concrete foundations can account for 15-35% of the total cost of
concrete installations. Essentially, the foundation gets built twice, once in
wood and again in concrete. Some companies have invested in aluminum forms that
can be reused. This becomes a more resource efficient solution although adding
labor in building and dismantling forms.
b) Features
- Non-solvent based damp proofing
- Regionally produced block or brick
- Western coal flyash concrete (minimum 15%)
- Frost-protected shallow foundation
- Aluminum foundation forms used
- Rigid insulation forms that provide permanent insulation to the foundation
- Insulated foundation with rigid R-10 foam insulation to footer
- Foam-insulated reinforced structural concrete slab
- Recycled concrete or glass cullet for aggregate
- Recycled-content expansion joint filler
c) Benefits
- Western coal flyash concrete has been used in foundation
Flyash is a by-product of coal-fired power plants. By mixing it with
concrete, not only is the foundation stronger but also it diverts the flyash
from landfills.
- Insulated foundation with Rigid R-8 foam insulation
Currently there are several alternatives available that use Styrofoam in
a variety of shapes and sizes to form walls. The foam forms stay in place
and serve as high efficiency insulation for the foundation that saves energy
and increases comfort. By installing rigid foam outside the foundation wall
it is unnecessary to have batts or spray-insulated walls in the basement
when finishing the space.
- Foam-insulated reinforced structural concrete slab
This foundation system solves problems with expanding soils, and the
foundation is insulated from the ground, which increases the comfort.
- Recycled concrete or glass cullet for aggregate
- Recycled-content expansion joint filler
These materials are generally available and help reduce dumping in
landfills by turning waste resources into a useful building product.
Category XII MATERIALS: SUB-FLOOR
a) Environmental Concerns
Plywood requires large diameter trees to effectively peel the plies for
lamination. Most OSB (and plywood) uses phenol-formaldehyde adhesive that is
less toxic that urea-formaldehyde but still out gasses formaldehyde into the
house. Some OSB uses a less toxic MDI resin base for its adhesive.
b) Features
- Urea formaldehyde-free sub-floor and underlayment material
- Oriented strand board (OSB) made from fast growth material
- Recycled-content underlayment
- No Luan underlayment used
c) Benefits
- Oriented Strand Board (OSB) used for sub-floors
OSB is another engineered wood product that reduces the demand for large
trees while improving the quality of the sub-floor. OSB uses a variety of
sources for cellulose fiber and adhesive types. OSB can be manufactured from
fast growing "weed" trees and uses a higher percentage of the
tree. OSB in conjunction with wood "I" joist floor framing can
reduce cellulose fiber requirements by 50% with superior structural
integrity
Category XII MATERIALS: EXTERIOR WALLS
a) Environmental Concerns
Wood siding contributes to the over-harvesting of our forests because to be
effective, it requires either clear material free of knots or large cedar or
redwood trees to be harvested. Pine siding is a poor alternative, as it can
warp, split or crack and needs to be repainted frequently.
b) Features
- Recycled-content sheathing (minimum 50% pre or post-consumer) or OSB
- Reconstituted or recycled-content siding (minimum 50% pre- or
post-consumer)
- Regionally produced brick
- Indigenous stone
- Natural stucco or synthetic plaster
- Cementitious siding
- Reconstituted or recycled-content fascia, soffit or trim
- Molded cementitious "stone"
- R-3.5 or better insulated exterior wall sheathing
c) Benefits
- Oriented Strand Board (OSB) used for sheathing
OSB is made from fast growing farm trees and, unlike conventional
plywood, does not tax diminishing reserves of large trees.
- Recycled or reconstituted content siding
Siding that has been engineered from wood fiber will not crack, split or
warp and holds paint longer, reducing maintenance costs.
- Natural stucco or synthetic plaster used
Stucco reduces air infiltration, drafts inside the home and reduces
maintenance costs.
Category XIII MATERIALS: DOORS
a) Environmental Concerns
Luan is a tropical hardwood that has been used for decades in new US home
construction. Excessive harvesting of Luan has left areas of the Asian-Pacific
devastated. Exterior doors are basically solid wood or foam wrapped in metal or
some other weather resistant material. Most insulated doors are relatively
similar in energy efficiency since the market is so competitive. The key
components in an efficient door are good weather-stripping and an effective
threshold. R-values of 5-7 are common.
b) Features
- No Luan interior doors
- Exterior doors (includes door to garage) insulated to R-5, or greater
- Reconstituted or recycled-content doors (hardboard) with least toxic
binders
- Solid, domestically grown interior wood panel doors
c) Benefits
- No Luan interior doors used
A decrease in Luan harvesting means less devastation to Pacific Rim
forests
- Reconstituted or recycled content hardboard doors have been used OR
- Solid domestically grown interior wood pane doors have been used
Reconstituted hardboard uses wood waste to create a paint-ready and
durable door that is stronger than Luan and does not harm the forests. Doors
made from domestically grown farm wood can also be used instead of Luan.
Category XIV MATERIALS: FINISH FLOOR
a) Environmental Concerns
Vinyl tile and other sheet flooring products whose primary component is
polyvinyl chloride (PVC) are already banned in some European countries because
of VOC off gassing. Toxic by-products are generally produced in their
manufacture. The EPA has identified carpet as a potential source of indoor air
pollution; it harbors dust, lead, pesticides, and other harmful chemicals,
including formaldehyde, which is used to glue carpet in place.
b) Features
- Recycled-content carpet pad
- Recycled-content carpet (tacked not glued)
- Natural linoleum with low toxic adhesives or backing
- Ceramic tile installed with low toxic mastic and grout
- Recycled-content ceramic tile
- Natural material carpet (domestic cotton, wool) tacked not glued
- Domestic wood flooring
c) Benefits
- Recycled content carpet pad
Recycled carpet pad is constituted of waste from the carpet industry,
providing the same comfort of a conventional carpet pad.
- Recycled content carpet
Creating a use for pop bottles diverts them from the landfill. Carpet
made from recycled "pop" bottles is competitively priced and is
more naturally stain resistant than virgin fibers used in conventional
carpet.
- Ceramic tile installed with low toxic mastic and grout
Ceramic tile is durable and long lasting. Non-toxic mastic and grout
have been selected to minimize the number of toxic chemicals introduced into
the house.
Category XVI MATERIALS: WINDOWS
a) Environmental Concerns
Windows lose heat through the frame, through the glass and let in cold air
between the window and the framing material surrounding it. Good windows make
the whole house more comfortable.
b) Features
- Windows with 1/2" airspace
- Finger-jointed wood windows
- Low-e windows NFRC rated at u=0.37 or lower
- Exterior environmental/insulated window coverings
- No metal-frames in house, including basement
c) Benefits
- Windows are double-glazed with 1/2" air space
- Low-e windows NFRC rated at u=0.37 or lower
Low-e is a coating that reflects heat in on cold nights and out on
summer days. It not only increases the R-value of the window by 50% it makes
indoor space much more comfortable year 'round. Low-e coatings have varying
effects that depend on the location of the coating (which surface of the
glass). However, even more important is the type of coating. The Solar Heat
Gain Coefficient (SHGC) will affect the amount of solar heat entering the
window, and should be above 0.5 on windows that function to add heat to the
space (south windows), as in a passive solar design or
"sun-tempered" design.
Category XVII MATERIALS: CABINETRY AND TRIM
a) Environmental Concerns
Particleboard is one of the largest sources of formaldehyde, a suspected
human carcinogen. It can off gas for 5 years into the living environment. It is
typically used for cabinet boxes, substrates in counter tops, shelving and stair
treads. Alternatives to particleboard are available that are formaldehyde-free.
Any use of particleboard should be sealed with a low permeability coating.
b) Features
- Any exposed particleboard is painted with water-based sealer inside
cabinets, underside of countertops
- Tropical hardwood trim or cabinets only if from certified
sustainably-managed forests
- Finger-jointed trim
- On-site application of cabinet finishes done with least toxic finishes
- Domestic hardwood trim
- Cabinets made with formaldehyde-free particleboard or MDF (medium density
fiberboard) or recycled agricultural products
c) Benefits
- No tropical hardwoods have been used unless from certified sustainably
managed forests
Tropical hardwoods are the lungs of the planet, keeping our atmosphere
healthy. Sustainably managed forests reduce the number of hardwoods cut.
- Finger-jointed trim
Clear wood trim gets more expensive as we deplete our ancient forests.
Finger-jointed trim is resource efficient by using short pieces of clear
wood glued together to create painted finished doors and windows that are
straighter and more stable than conventional clear wood.
CATEGORY XVIII MATERIALS: ROOF
a) Environmental Concerns
Petrochemical products are still the base for most residential roofing
products. These conventional products only have a 15 or 25-year life span, which
makes them resource intensive, since shingles are rarely recycled. Once old
shingles are taken to a landfill, these materials virtually never break down.
Toxins from shingles leach into landfill soil and then into the groundwater.
b) Features
- Recycled-content roof material
- Minimum 30-year roofing material including concrete, slate, clay,
composition, metal or fiberglass
c) Benefits
- Minimum 30-year concrete roofing installed
Typical asphalt roofing must be replaced after 15 years. Alternatives are
available in steel, plastic, and cement that use recycled content materials
and come in shake or shingle looking styles. All have longer life spans than
asphalt or fiberglass shingles and can be recycled. Concrete roofing saves
money over the life of the home and is fire proof
Category XIX MATERIALS: FINISHES AND ADHESIVES
a) Environmental Concerns
More than any other category, these products adversely affect indoor air
quality, especially immediately after installation. The health hazard is
particularly acute for installers. Most conventional products off-gas VOCs,
formaldehyde and other chemicals that are generally used to enhance the
performance and shelf life of the product. VOCs are what produce that "new
house" smell. VOCs are not healthy to breathe, however. In addition, floor
finishes can be one of the most toxic elements in the home. The chemicals found
in these finishes out-gas for months creating an unhealthy indoor environment.
The medical research community has raised questions concerning the toxicity of
combined chemicals on human health. Quality substitutions that are lower in
toxicity or are non-toxic are now available for all of these products.
b) Features
- Paints and finishes that have minimal VOC content (less than 250 grams per
liter)
- Paints or finishes with recycled-content
- Only low-toxicity, solvent-free adhesives used throughout
- Water-based urethane finishes on wood floors
- Water-based lacquer finishes on woodwork
c) Benefits
- Paints and finishes contain minimal volatile organic compounds (VOCs)
Lower VOC paints increase indoor air quality by reducing exposure to VOCs.
- Water-based urethane finishes on wood floors
Water-based finishes are much less toxic than conventional products and have
proven durable and attractive.
Category XX MATERIALS: INSULATION
a) Environmental Concerns
The environmental effects of insulation types and levels are greater than
most other building materials. The level of insulation and the quality of
installation make a major difference in how much energy the house requires for
heating and cooling. Adding increased insulation to a ceiling is only beneficial
if it is installed appropriately; a California study concluded that a 4% void in
fiberglass batts resulted in a 50% decrease in insulation effectiveness. In
another study the same wall section, one framed with wood 2x4s and the other
with steel 2x4s sheathed in I " foam board resulted in 35% greater heat
loss through the steel because of the thermal conductivity of the steel.
Fiberglass insulation is the standard in the industry today. High-density
fiberglass makes the same wall cavity 15-20% more effective in reducing heat
loss. The manufacture of fiberglass can incorporate 10-30% recycled material.
Most fiberglass batts use formaldehyde as a binder, although in minor amounts.
Cellulose is primarily made out of recycled wood fiber from pre-consumer
waste and from newsprint. When it is properly sprayed it forms a good
infiltration barrier adding to the air tightness of the house. It is less
contractor-dependent for quality control in filling voids than batt insulation.
It can be blown dry, or mixed with a binder and sprayed.
Rigid foam insulation applied to framing yields added infiltration
resistance, reduced frame conduction losses, added effective total wall R-value.
Most rigid foams now are CFC-free, using HCFCs as a blowing agent instead.
Although much better than CFCs, HCFCs still contribute to ozone depletion and
slowly out-gas from the insulation over time. As a greenhouse gas, HCFCs are
150-500 times worse than C02 in contributing to global climate change.
Polystyrene rigid foam can be produced HCFC free.
b) Features
- Recycled-content (minimum 25%) insulation
- Home has wet blown wall insulation such as cellulose or fiberglass
- Cellulose insulation with UL-rated fire retardant
- HCFC-free rigid foam insulation
- Formaldehyde-free insulation
- Non-toxic spray foam insulation
c) Benefits
- Recycled-content (minimum 25%) insulation
Using recycled content lowers the amount of material in landfills and
uses an otherwise wasted resource.
- Home has wet blown or dense pack wall insulation such as cellulose or
fiberglass
This type of installation typically results in better coverage of the
insulation and, therefore, better overall insulating value of the wall.
There is evidence that this method also helps reduce air infiltration.
- Cellulose insulation with UL-rated fire retardant
Cellulose insulation is made primarily from recycled newsprint, helping
to "close the loop" on recycling. The recycled content in
cellulose is at least 80%.
- Formaldehyde-free insulation
- Non-toxic spray foam insulation
Reducing Volatile Organic Compounds (VOCs) and their potential for
affecting indoor air quality will add to the health attributes of the home.
Category XXI WATER CONSERVATION
a) Environmental Concerns
Conserving water inside the home saves energy and reduces our need for water and waste
treatment. By installing water efficient faucets and showerheads, a typical
family can save $60-120 per year. That translates into roughly 17,000 gallons of
water saved. Typical showerheads use 3.5-6 gal/min. A water efficient showerhead
reduces the flow to less than 2.5 gal/min. without sacrificing water pressure.
The water we use on our landscaping, however, consumes the lion's share and
chemical fertilizers and pesticides pollute the ground water. Careful planning
of the landscape and irrigation systems can greatly reduce its water needs.
b) Features
- Permeable materials (40% of areas for all walkways, patios and driveways)
- Grass that uses less water
- Installed landscape is Xeriscape that is more than 50% of non-paved area
- Rainwater harvested and directed toward landscape needs where practical
- Landscape with native drought resistant plants
- Provide a list of native drought resistant plants to homebuyers
- Bathroom faucets fitted with aerators restricting flow to no more than 1.8
GPM
- Kitchen faucet fitted with aerator restricting flow to 2.0 GPM
- Energy Star qualifying clothes washer
- Passive or on-demand hot water delivery system installed at farthest
location from water heater
- Recycled-content mulch or compost
- Installed bedding areas are mulched
- Installed irrigation system is zoned separately for turf and bedding areas
- Installed irrigation system includes a soil moisture or rain sensor, or
other irrigation efficiency device
- Install three cubic yards of soil amendment material per 1000 square feet
of installed landscaped area, based on soil analysis
c) Benefits
- Grass has been planted that uses less water in lawn areas
- Xeriscaping with native, drought-resistant plants
- A list of other native, drought-resistant plants has been provided
Outside watering often consumes up to 60% of Front Range water every
year. Our water future is very important to us. We have attempted to reduce
the impact of our homes on our limited water supply.
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