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
Health
Comfort
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:
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
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.
Call Laurie to help you find homes that are built green...
Call me Today at
(303) 777-7435
LaurieKing@DenverHomesForSale.com