Green Remodeling Guide: From Indoor Air Quality to Energy Efficiency

Comfort and Temperature

• Conduct an energy audit. To do a step-by-step audit yourself, see your local utility’s website or the U.S. Department of Energy’s site. Utility companies or state energy offices sometimes conduct free energy audits; you can also get an in-depth home energy rating system (HERS) assessment for a few hundred dollars.

• Install ample insulation. Most homes will get maximum benefits by insulating an attic space or adding to existing insulation. Follow up with walls, then unconditioned crawlspaces or basements. Eco-friendly insulation choices include cellulose, cotton, and formaldehyde-free recycled-content fiberglass.

• Seal major air leaks. A formal energy audit will determine how much air is leaking into the house and whether ducts are leaking. Fix common gaps by weather-stripping doors, caulking windows and baseboards, and caulking corners where the siding comes together. Visually inspect duct joints to ensure they’re sealed with mastic instead of leaky duct tape.

• Test for backdrafting. Leaky return ductwork, fireplaces, heaters, and other gas-combustion appliances could send carbon monoxide back into the house instead of exhausting it. Backdrafting also occurs when there’s negative air pressure in tightly sealed homes. To test for backdrafting, turn on all the appliances, including the clothes dryer, bath fan, and stove fan, and hold lit incense or a match in front of the draft hood located at the front of the water heater. If the smoke goes up the flue, it’s not backdrafting. If it goes back into the room, you have negative air pressure and backdrafting, and you may need to install a ventilation system.

• Replace single-pane windows with double-glazed. Upgrading windows can improve the comfort of a room dramatically. Double-glazing provides insulation; low-emissivity (low-E) coatings enhance temperature by reflecting heat back into a room in the winter or deflecting heat away during the summer. Look for low-E coatings designed specifically for your climate and window orientation.

• Carefully evaluate mechanical systems. Heat or cool just the areas where you absolutely need it, and look for high-efficiency systems. If you’re putting in a new system, have your contractor calculate the correct load precisely instead of using a ballpark estimate based on cubic feet. Avoid units that use the ozone-depleting refrigerant R-22, currently being phased out but still sold today. In dry climates, install an evaporative cooler, which uses about 30 percent of the energy a conventional air conditioner requires.

Indoor Air Quality

• Perform an indoor air analysis. Minimize sources of poor indoor air, including chemical storage, pet areas, and wall-to-wall carpeting.

• Install a kitchen range hood and bathroom exhaust fans. Kitchen hoods remove moisture, smoke, grease and, in some cases, unburned gas. Bathroom fans reduce moisture build-up and mold growth.

• Add a good-quality filter to your HVAC system. A high-performance filter, which will cleanse the air of nearly all particles, can be had for a few hundred dollars.

• Install a garage exhaust fan. If you have an attached garage, reduce the amount of fumes and pollutants that enter the house by installing an exhaust fan.

• Get a carbon monoxide (CO) detector. Unvented or malfunctioning appliances can cause problem levels of CO.

Interior Renovation

• Recycle materials you tear out. Wood, concrete, cardboard, and metal scrap can all be recycled. Your local salvage yard may also want your old fixtures, cabinets, appliances, doors, and windows or other leftover construction materials.

• Paint with low- or no-VOC finishes. Minimize fumes by using water-based paints with minimal amounts of volatile organic compounds (VOCs). A recommended list of paints is available at GreenSeal.org.

• Remove wall-to-wall carpet. Carpets harbor dust, dust mites, and dirt. Choose more durable, easier-to-clean flooring such as cork, bamboo, Forest Stewardship Council-certified (FSC) wood, or natural linoleum. For bathrooms, consider recycled-glass ceramic tile.

• Bring in natural light. A tubular skylight—a plastic dome with a metal tube that reflects light down through a diffuser—is cheaper and easier to install than a standard skylight. Skylights are suited only to mild climates because they lose and gain considerable heat.

• Choose Energy Star appliances. Replace your refrigerator—typically the biggest single electricity user—if it’s ten or more years old. Other energy guzzlers include dishwashers and laundry appliances.

• Make your hot-water system more efficient. If you have an old water tank, insulate it with an inexpensive water tank jacket; with new models, look for an R-16 insulation rating. Save time and an estimated 10,000 gallons of water a year by installing a hot-water recirculation system. Set on a timer, the pump circulates hot water continuously during peak use. The most environmental solution is an “on-demand” pump that supplies water only when you need it. Tankless water heaters, which heat water on demand, are more energy-efficient, but they’re expensive and supply a limited amount of hot water at a time.

• Minimize particleboard use. Substitute solid wood, formaldehyde-free medium-density fiberboard (MDF), or wheatboard for particleboard in cabinets. Particleboard contains formaldehyde, which continues to outgas long after it’s installed.

Deck and Garden

• Landscape with drought- tolerant plants. Figure out which areas of the yard don’t get heavy traffic and replace the grass with perennial groundcovers. Put in native plants, which require less water and provide natural habitat for wildlife. For landscaped areas, install drip irrigation systems, which use less water than sprinkler heads and cut down on weeds.

• Minimize wood for decks and fences. Use recycled plastic lumber, composite lumber made from wood fiber and plastic, or FSC-certified wood instead. For structural elements such as fence posts that require pressure-treated wood, look for products that aren’t treated with arsenic, a carcinogen that can leach into the soil and be absorbed through skin contact.

• Install permeable paving. Instead of one giant concrete slab, walkways made from spaced pavers or gravel allow water to drain into the ground and filter through the soil, rather than washing into storm drains and concentrating pollutants. Permeable driveways may also be appropriate, depending on your region.

New Additions

• Take the sun into account. Figure out where the sun will be and use that information to orient additions and windows. Create shade for south-facing walls and windows with landscaping or architectural features.

• Use engineered or FSC-certified wood for framing. Some framing lumber still comes from old-growth forests, but engineered wood typically uses waste wood or fast-growing farmed trees and is stronger than regular wood. FSC-certified wood is sustainably harvested.

• Use light-colored roofing materials. Regardless of whether a home is in Alaska or Arizona, a light-colored roof is best for interior comfort and energy use. Because the sun is at a low angle in the winter, you can’t get much heat gain from the roof; in the summer, the sun’s high angle creates significant heat problems in homes with darker roofs.

• Check “green” materials with local code officials. Before you start renovating, find out what restrictions on materials might cause you problems. Some states are restrictive about less mainstream construction methods.