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, 1854

by Francesca Lyman, reprinted from Green Guide, June 21 '96, with permission
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 budget."

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.

CHECKLIST:
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.

 

Site

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 wildlife habitat.

 

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

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, Cotman says.

 

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.

 

Roofs

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 home does.

 

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.

 

Ventilation

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 Natural Home.

 

Windows

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 of PVC.

 

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.