Blueprint for the New Green Home
"What is the use of a House if you haven't got a tolerable planet
to put it on?"-Henry David Thoreau,
by Francesca Lyman, reprinted from Green Guide, June 21 '96, with
century and a half since Thoreau built his little cabin
on Walden Pond, our poet's ethic of simplicity and harmony with nature has
been displaced by the typical American dream house: a multi-thousand-square-foot
suburban palace with a three-car garage. If we took Thoreau on a tour, he'd
be surprised to learn that today's building products and furnishings emit
gaseous volatile organic compounds (VOCs) such as the known carcinogens
formaldehyde and benzene, and trigger respiratory, allergic and neurological
reactions. He'd see bulldozers mow down trees to make room for a house -
built with scarce hardwoods from far-flung places and construction
crews filling dumpsters with enough scrap wood to build another Walden cottage.
Not all homes built today, though, are monuments
to waste, sick-building syndrome and pollution. For more and more people,
the new dream home is a green home. In this article, you'll find home projects
done in ways to save energy, water, materials and doctor's bills.
Taking inspiration from traditional "sustainable" dwellings, such
as pueblos and yurts, the new green home of the 1990s seeks "to repair
the ruptured link between us and the rest of nature," write Janet Marinelli
and Paul Bierman-Lytle, authors of Your Natural Home.
Whether you're building from scratch or just
remodeling one room, "Why not do it the right way?" suggests Diane
Cotman, director of the Sustainable Housing Demonstration Project in Cambridge,
Massachusetts. Cotman is working with architect Gerard Ives to create a
model for a green home "...in a way that anyone could do it, on any
Rehabbed, recycled and resourceful
Cotman's future green home stands on Appleton
Street in Cambridge, right in the heart of an old city neighborhood. (Easy
walking distance to downtown will make the occupants less dependent on cars.)
A three-story, drafty wood-frame, the house was a poorly insulated energy
hog with some hazardous lead-paint-covered walls.
The overall conception is to rehab the 1928
structure for the future, but with off-the-shelf materials. The architects'
plan also reinforces the neighborhood's historic identity, preserving the
Arts and Crafts style of the house.
With regard to structure, the Cambridge House
designers discovered that many of the 1920s-era materials in place were
actually less toxic than their modern counterparts. Thus they preserved
such major features as the foundation, side walls, hardwood floors and roof
and wall shingles.
The following checklist gives advice from professionals
and examples from the Cambridge and other houses on how to start drawing
up your own green blueprint.
How to Get Started
- Healthy House Checkup
- Start by identifying such pollutants as: emissions from improperly
vented gas or oil appliances; mildew and mold; VOCs from plywood, adhesives,
wallboard, cabinetry, carpeting, flooring, foam and upholstery. (Older
materials are safer - after five years most VOCs will have outgassed completely.)
Test for asbestos, radon, and lead from old wall paint.
- If you are building from scratch, you want to start with a north-south
orientation, with many south-facing windows to capture solar energy. Take
a cue from your surroundings: use native stone or wood and you'll save
shipping costs and energy while staying faithful to your landscape. Make
sure your floor plan follows the local topography and preserves trees and
- Check your site's proximity to potential problem areas: for example,
chemical leaks from underground gasoline tanks or landfills; facilities
likely to be sprayed with pesticides, such as golf courses; and sources
of electromagnetic radiation, such as high-voltage lines.
- Foundation and Moisture Protection
- If you can, reuse an existing foundation. If not, look into a more
environmentally sound, lighter-weight, aerated concrete, such as Faswall.
Conventional foundation waterproofing sealants emit VOCs; have your builder
use safer alternatives, such as Dynoseal (for the exterior; subterranean
foundation) and Penetrating Water Stop (for the interior face).
- Insulation poses a multitude of environmental dilemmas, whether it's
an ozone-depleting foam or a fiberglass that outgasses formaldehydes and
releases particulates. The Cambridge House will be insulated with blown-in
recycled newspaper. Paul Novak of Environmental Construction Outfitters
recommends recycled cotton insulation or low-E radiant barrier made of
microcell polyethylene core sandwiched between sheets of reinforced aluminum
foil. Because the cotton is treated with fire retardant chemicals, you
might want to use a non-VOC sealant on the walls.
- Energy-Waste Not
- Check your house for leaks. The Cambridge House will be tightened up
to require less energy. The architects decided to "pop out" the
attic, building the house higher to capture more solar energy. Photovoltaic
panels store electricity. Solar hot water heaters are retailing now for
as low as $2,000 with installation. At Cambridge House, a ground-source
heat pump will tap into a geothermal well beneath the house, providing
energy for winter heat, cooling in the summer, and hot water year-round.
It costs $5,000 - about 20 to 25 percent more than conventional energy
but it will pay for itself through savings in five to six years,
- Interior Walls, Ceilings and Flooring
- Plywood - used both in interior walls and in sub-floors and particle
board contain toxic binders and glues. If you can't find affordable all-natural,
untreated wood, seal in those VOCs (ECO recommends Safeseal). Avoid veneers
made of tropical forest species. The safest floorings are natural (not
vinyl) linoleum and cork, untreated hardwood, ceramic tile, marble and
slate. Big City Forest, in New York, makes flooring from reclaimed wood.
- Exterior Walls
- Framing lumber conventionally comes from such old-growth species as
Douglas fir and white pine, which are dwindling rapidly. Turn to cheaper
spruce, especially local, domestic species, and use lumber from woods deemed
"sustainable" by reputable certification groups, such as Scientific
Certifications Systems. If you're worried about termites, have your lumber
treated with Timbor; a low-toxicity boric acid product.
- The safest roofs are probably cedar shingle or metal, according to
ECO. You can also use aluminum made from recycled beverage cans; slate
shingles; or galvanized steel molded to look like tiles. Recycled asphalt
shingles may outgas petrochemicals downwards (as well as up).
- Water Systems
- Low-flush toilets use half the water of conventional ones. To conserve
"drinking water that for the most part gets flushed down the toilet,"
Cotman is installing composting toilets (a good brand is the Clivus Multrum)
and low-flow faucets and showerheads.
- The Cambridge House will also have an innovative "greywater"
system, in which wash water goes to gardens or is recirculated to the house's
indoor plants, which oxygenate and filter impurities from the air. Cotman
is working with Home Depot and the plumbers' union to cut the costs of
greywater systems for future consumers.
- Another new option: with a revolutionary rainwater collection system,
the updated-traditional Florida "Cracker" House in Sarasota draws
40 to 60 percent less from the public water supply than the conventional
- Water filters
- A good "solid block" carbon filter can be attached to your
sink's plumbing and will remove chlorine, most bacteria, parasites, chemicals
and most heavy metals.
- One of the most important air-quality steps for the Cambridge house
will be a built-in heating, ventilation and air conditioning (HVAC) system.
But remember: no ventilation system can replace such simple details as
windows that can readily be opened and closed. Whole-house ventilators
cost about $700; $3,000 with duct work and labor, according to Your
- Look for energy-efficient (R-5 or R-6 rating; most windows have R1)
and low-emissivity windows with a coating that reflects heat but lets in
light (ask for low-E, or heat-mirror windows). Don't use polyvinyl chloride
(PVC) window frames. Dioxins are released during the production and incineration
- Floor, Wall and Other Surface Finishes
- Use low-VOC and low-toxic finishes, such as water-based Skanvahr, on
drywall and flooring. If you're not allergic to them, natural resins and
beeswax products, natural shellac and linseed oils or Tung oil are additional
less-toxic, if more expensive, alternatives.
- Pipes and Plumbing
- Replace lead pipes and soldering. For new pipes, use copper pipes and
intakes, not PVC.
Francesca Lyman writes frequently for environmental and science journals.