Are you shopping for a new home? Naturally, you are savvy and understand that we spend 90 percent of our time indoors and that our buildings contribute over 40 percent of the nation’s C02 emissions and, therefore, you’re looking for a healthy, energy-efficient home.
Advertisers have figured out that green sells, which means everyone is claiming that they are green. How do you find a builder or home that really is environmentally responsible?
The house should have measurable and verifiable means of showing how green it is, and preferably have third-party certification. A green home is energy efficient, but it should also address concerns about the location, quality of construction, water use, material selection, and air quality.
Site/location. You should look for a house that is located within biking or walking distance of everyday services such as the grocery store, school, community center, and library. Is there good southern solar exposure?
Quality of construction. Ask if a third party inspected the house during construction. It should be inspected at least three times: before the floor slab is poured and under-slab piping/wiring is covered; before the drywall is installed; and the electrical and heating and cooling systems should be tested once construction is complete. An inspector is focused solely on safety and performance and can catch things overlooked by a busy builder. Ask about the durability of exterior materials. How often will materials like the roof, siding, and windows need maintenance or replacement? Are extended warrantees available, and how are they backed up?
Water use. What type of water-saving fixtures are installed? The standard toilet has a 1.6 gallon flush. There are good quality toilets that have a dual flush (1.3 gallons and .8 gallons) and a low flush of 1.28 gallons. Sinks should have aerators on the faucets. An average shower uses 3 to 5 gallons per minute. Avoid spa-type showers, which can use up to 30 gallons per minute.
Energy use. Can your builder show you how much you can expect to pay for utilities? A quick way to know is to ask if the house has received third-party certification, like Energy Star or Leadership in Energy and Environment for Homes (LEED-H). These rigorous certifications require the builder to model the expected energy use and provide assurance that the builder knows how to construct an efficient home. The builder should be able to explain the insulation values of the walls, attic, windows, and doors. The Department of Energy recommends walls in Iowa to have a thermal value of R-18 and the attic to be R-49.
Control of air infiltration is as important as insulation values, as 31 percent of air leaks are found in walls, floors, and attics. The house should have a house wrap like Tyvek, and every nook and cranny of the exterior should be sealed against air leaks. This helps keep the heat in the house and reduces drafts, making for a much more comfortable home. A tightly constructed house can also trap moisture in the walls and attic. Ask your builder to explain how the attic is vented and how the walls are designed to allow moisture to exit the walls, while keeping air out. A tight house should have a heat recovery ventilator to intentionally introduce fresh air, and bath/dryer vents need to vent to the exterior. If your builder can’t answer such questions, keep shopping. Moisture in the walls and attic can cause dangerous mold problems years later.
Air quality. I visited a model home last month where, within 20 minutes, my eyes were watering. The paints, adhesives, and plastics in the house were making me sick. A green builder should carefully select materials for a good indoor air quality. They should select low-VOC materials (volatile organic compounds), adhesives, and particle board with no added urea formaldehyde, and avoid wall-to-wall carpet, which is guaranteed to collect a wide range of allergens.
Within one year or so, most of the “new house” smells should be gone. After that, the largest sources of air pollution are from cleaning supplies and what enters on your feet. Either buy non-toxic cleaning supplies or make your own, and take your shoes off at the door. Lastly, invest in a good quality pleated air filter with a rating of at least a MERV-8.
Material selection. Ask your builder about the criteria for material selection. In addition to looking at air quality, I research how far materials come and from what sources, how much energy is required to manufacture them, if they have recycled content, if the material is natural or synthetic (natural is often, but not always, better), and their durability and ease of maintenance. Weighing all these factors is a difficult balancing act. The key is to determine if your builder has been deliberate in making his decisions.
Resources:
www.greenhomeguide.org
www.eere.energy.gov/buildings/info/homes/