As people have become more aware of environmental concerns, so has the building industry. Choosing to add on to your existing home instead of building a larger one somewhere else is in itself an environmentally friendly decision. Here are 16 environmentally conscious steps you can take during the design and building processes
1. Choose Building Materials Wisely
The first step is to use local materials for your project when possible. You can also build with engineered wood products—wood joists, trusses, and other structural members that are made from smaller stock. Engineered wood products are stable and consistent in strength and precision. Composite materials made of recycled wood and plastics are available for many uses, including decking and trim work. Use water-base paints and finishes.
2. Consider Your Flooring
Some types of flooring contribute to indoor air contamination due to the volatile organic compounds (VOC) used in their manufacture. Linoleum and natural-fiber carpets come from renewable resources and are durable. The cork used in linoleum is harvested from the cork tree without damaging it. Carpet-type flooring made from grasses and reeds is available. Hardwood, bamboo, stone, and ceramic tile are other choices. Air out your house after installation when adhesives are used.
3. Check Insulation
Use loose-fill insulation made of cellulose fiber from recycled paper. Also check the insulation of the existing house—including the heating and cooling ducts—to make sure it's properly insulated. Install windows with insulated glass.
4. Maximize Solar Energy
Take advantage of passive solar heating by making the most use of the sun's heating effects in the winter, and by reducing exposure to the sun in the summer. Key aspects include the proper solar orientation of the addition and proper window placement and ventilation.
5. Choose Energy-Efficient Appliances
There can be a significant difference in the energy consumption of some appliances. EnergyGuide labels are attached to all major appliances so you can select the most efficient models. These labels compare the model with the energy and water consumption of other similar models.
6. Install Vapor Barriers
When installed correctly and coupled with proper mechanical ventilation equipment, vapor barriers help promote indoor air quality by preventing moisture and pollutants from seeping in. They also reduce drafts, thereby cutting energy consumption.
7. Use Non-VOC Products
Pressure-treated building products contain volatile organic compounds (VOC) such as formaldehyde, which can leach out over time and may pose a health hazard to those who suffer prolonged exposure. Untreated, kiln-dried lumber, steel studs and joists, and plastic-impregnated wood-composite planks are some of the many alternatives that qualify as non-VOC materials.
8. Plan Healthy Siting
Poor drainage and a leaky basement can lead to hazardous mold and mildew growth inside the walls or on interior surfaces. Proper siting is one way to head off these problems. Make sure your addition won't disrupt natural drainage patterns on your property. If you're concerned about groundwater drainage, consider building your addition on a well-ventilated crawlspace foundation, a concrete slab, or on piers. Other good measures include adding a layer of plastic sheeting under the basement floor slab and installing a dehumidification system.
9. Seal the Foundation with Ventilation
Check to see if basements in your neighborhood or area are prone to exposure to radon gas, a proven cause of cancer . If you live in a high-radon area, you may want to rule out below-grade living space in your planning, and you may also want to install a special radon-venting system in your existing basement.
10. Plan for Cross-Ventilation
The exterior envelope of a new house or addition is built much tighter than those a few decades ago. This results in lower exchanges of indoor air per hour. To ensure adequate natural ventilation (a more earth-friendly remedy than mechanical systems), it's best to go with a floor plan that allows windows on at least two walls in all the main rooms.
11. Use Recycled Materials
Many exterior finishes are made with recycled materials or byproducts (green materials), which helps conserve resources. The manufacture of some of these green materials also uses less energy and/or produces fewer pollutants, thus helping to protect the environment. Examples of these green materials include slate-style shingles made from ground-up quarry waste, driveway pavers made with recycled rubber tires, and masonry veneers made with pulverized-stone chips.
12. Choose Paints With Low or No VOC
Unlike conventional oil- and water-base paints, the "green" versions are practically odorless and contain very small amounts of chemical fumes that outgas quickly after application.
13. Use Solid-Wood or UF-Free Products
Glues and binders used in the manufacture of many cabinets, furniture frames, and structural and decorative panels contain urea formaldehyde (UF), which outgases VOC. Look for solid-wood or UF-free alternatives.
14. Look for Sealed-Combustion Gas Appliances
Pilot lights on conventional gas-fired appliances, such as stoves, water heaters, and gas fireplaces, continuously release small amounts of carbon monoxide, not all of which escapes to the outdoors through vent pipes. To avoid buildup (a special concern in extra-tight houses), install sealed units that use outdoor air for combustion or an electronic spark for ignition instead of pilot lights.
15. Get a Water-Filtration System
Urban growth is threatening the availability of clean water sources for metropolitan treatment facilities. Build in extra precautions against pollutants by installing point-of-use filtration equipment (undercounter or faucet-mount), or invest in a whole-house filtration system.
16. Install Low-Voltage Lighting
Conventional lighting systems use line-voltage wiring and incandescent lamps (bulbs), which waste energy by producing heat as well as light. In low-voltage systems, a transformer steps down the voltage, and special types of bulbs (such as fluorescent or halogen) convert most of the energy to light.