You want to build an environmentally sensible house. One that is “green” with good indoor air quality, energy efficiencies, and, wherever possible, materials that are environmentally benign.
But how, exactly, do you do this? What makes building materials green and how do you find out about them? While there’s an abundance of information out there, it hasn’t been systematically organized for the time-starved homeowner who is starting from square one. Until now.
“Green Building Products,” a guide for residential building products has just been published by BuildingGreen and New Society Publishers. It is written by the editors and staff of Environmental Building News, one of the most authoritative publications on environmentally responsible building design and construction in the country.
The listings in “Green Building Products” do not cover all the items you will need to build a typical house. Lead editor Alex Wilson said in an interview that they did not include everything because in some categories no green products are yet available, for example, garage doors, bathroom sinks, tubs and shower surrounds.
If you’re a home building novice, the overviews provided at the beginning of the book, each of 23 product categories (for example “roofing”), and each individual section (for example “plastic shingles”) will be especially helpful in explaining the degree to which construction activities affect the environment, and why the criteria for determining that a building product is green is very broad.
As defined by the editors of “Green Building Products,” a product may be considered green if:
1) It’s made with recycled, salvaged or agricultural wastes (most commonly crop straws);
2) It conserves natural resources because it’s especially durable or it’s made with a rapidly renewing material such as bamboo that can be harvested every ten years;
3) It enhances indoor air quality because it has low or no emission of toxic chemicals into the air or because it helps block the introduction of indoor contaminants such as mold;
4) Its manufacture does not produce toxic emissions;
5) It saves energy or water;
6) It reduces the environmental impact of the construction itself. For example, porous driveway paving products absorb a substantial amount of the rain that hits them and this reduces the amount that runs off into a local and often overwhelmed storm water collection system.
Within each category of green products there are also shades of green. A material can be green because it’s made entirely or partially with recycled materials. But, the editors tell us, it will be greener if the recycled material is post consumer waste, instead of post industrial waste, because consumer waste is more likely to end up in a landfill and overflowing municipal landfills is a bigger problem than the waste piles that accumulate at factories or generating plants.
The information provided in the product category summaries tells you that even the most seemingly innocuous product can have its downside — for example, the cement mixed into the concrete used for foundation walls, footings, and basement and garage floor slabs.
Cement is the critical ingredient that makes sand and gravel bind together and become hardened concrete. Its manufacture is both energy intensive and polluting. When a ton of cement is made, up to a ton of carbon dioxide is released into the atmosphere. The environmental effects of cement can be lessened, however, if the amount of cement mixed into concrete can be reduced without affecting its structural integrity.
One such substitution is fly ash, itself an industrial waste created at coal burning power plants. Moreover, fly ash actually strengthens the concrete because it changes its chemical properties. Your concrete will be greener still if you substitute recycled glass cullets for gravel. The cullets are made in part from the glass bottles you put out every week in your recycling bin.
Another surprise — a more simply built house that harks back to preindustrial American is not necessarily a greener one. A log cabin without a lot of 21st century modifications is not green at all because wood is not a great insulator. For energy efficiency you’re better off to build a house with conventional wood frame construction and beef up the insulation or use a newer man-made product such as structural insulated panels (SIPS), which have a layer of plastic foam sandwiched between two sheets of oriented strand board.
It will take you awhile to absorb the information in this book. But eventually you will start selecting things, and then you’ll undoubtedly discover, as everyone who ever builds a house does, that you have to prioritize because you can’t afford everything you want. What are sensible priorities when building a green house? What would Green Building Products editor Alex Wilson’s be?
Wilson said his first concern would be energy consumption. It’s important to use materials that don’t negatively impact the environment, but, he pointed out, you only build a house one time, and you will be using energy everyday that you and subsequent owners live there. Over time, this will have a far greater impact than the construction of your house. Wilson said he would spring for things like energy-efficient windows, beefed up insulation, and a high efficiency furnace and air conditioning compressor. And, because he lives in Vermont with its frigid winters, he would explore the degree to which he could incorporate passive solar heating, which is free and renewable.
Wilson’s other priority would be the health of his household. He would want to ensure that they would have good indoor air quality. To that end he would select materials that have low or no emissions of volatile organic chemicals (VOCs), unstable compounds that off gas into the air from synthetic building materials commonly used in residential construction.
The VOC that Wilson would most avoid is formaldehyde, a potent eye and nose irritant that can cause respiratory problems; in 2004 it was classified as a confirmed human carcinogen by the World Health Organization. A number of building products off-gas formaldehyde, but the worst offenders in Wilson’s estimation are kitchen and bathroom cabinets made with particleboard that contains urea formaldehyde. Although the cabinet industry has greatly reduced the amount of urea formaldehyde in its products over the last 15 years, Wilson would still want cabinets that are formaldehyde free.
Wilson also stressed that building a green house involves more than prudent material choices. You also have to consider the construction. For example, you’ll need to plug up all the air leaks in the building envelope so you’re not heating or cooling the great outdoors.
Pulling back for the big picture, Wilson said where you build is another important consideration. If your site is far from your workplace and even from the closest store to buy milk, the exhaust fumes from all that driving will undo some of the good accomplished by building a green house.
For further information about the Building Green organization and its publications, see www.BuildingGreen.com.
If you are planning to build an environmentally sensitive, green house and indoor air quality is a special concern — someone in your household has asthma, for example — you will want low-emitting building materials. That is, products that do not emit significant amounts of volatile organic chemicals (VOCs), unstable compounds that off gas into the air from many building materials used in construction today. For sensitive individuals, VOCs can be toxic, even in small amounts.
One place to find information about low-emitting products is the website of the Greenguard Environmental Institute (www.greenguard.org). This organization, which was established in 2000, tests the level of emissions given off by individual building products and certifies the ones that meet its emission standards. These are a combination of standards set by the EPA, the State of Washington and several European governments. Greenguard’s combined standards are more stringent than any individual standard on which they are based, including those of the EPA.
Greenguard tests for 65 chemical compounds, but the one that concerns most people is formaldehyde, a potent eye and nose irritant that can cause respiratory problems and has been classified by World Health Organization as a confirmed human carcinogen.
As part of Greenguard’s testing protocol, products are tested every quarter. The products are tested within one week of their manufacture. Although the rate of emission for most products is very high initially and then falls off significantly after the first few weeks or months, Hemming Bloech, Greenguard’s Communications Director, said that they test the worst case scenario because the products installed in your house may have come straight from the factory or have been stored in a warehouse for months tightly encased in factory-applied shrink wrap that prevented the VOCs from off-gassing.
Most of the certified products Greenguard lists on its Web site are geared towards commercial construction, but many of them can be used in residential work as well.
In addition to building materials such as insulation, Greenguard’s certified products list includes furniture and drapery because these items also emit VOCs. In fact, Bloech said that their testing has shown that furniture “is often the biggest culprit” because it’s made with as many as 30 different materials including glues, resins, foam padding and upholstery fabric, and many of them are emitters.
The two furniture companies on the Greenguard certification list, Knoll Furniture and Herman Miller, are well known in the commercial sector, but may not be familiar to many homeowners, though both firms make residential pieces. Knoll has had both types certified as well as wall coverings, drapery, and textiles that are used by other furniture manufacturers. Herman Miller elected to have only its commercial furniture tested and certified, but many of these pieces would also be suitable for a home office.
Greenguard Web site visitors will also find some familiar brand names. Formica plastic laminates are on the list as are many products from WilsonArt.
Questions? A home-building story you’d like to share? Katherine Salant can be reached at www.katherinesalant.com.
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