Habitat for Humanity of El Paso has built energy-efficient, passive solar homes since 1994. The affiliate's research shows that these design features save homeowners $25 or more per month in utility bills, while adding only $5 per month to mortgage payments. HFH El Paso became so convinced of the new design's value that the affiliate rewrote its bylaws to require these new criteria.
HFH El Paso is the first house builder in that city to earn the Environmental Protection Agency's "Energy Star" certification. The affiliate reports that El Paso receives more solar energy per square meter than any other city in the United States, making passive solar design especially suitable for local construction.
• Passive solar design: reduced east and west facing windows to reduce unwanted heating, reduced north-facing windows to reduce conduction heat losses.
• Exterior walls with perimeter slab insulation, sill sealer, caulked sole plate, polystyrene sheathing and R-13 wall insulation (appropriate for climate).
• Insulated air gap windows and steel insulated doors.
• Sealed door and window openings, top plate, wall, Sheetrock, and exterior penetrations.
• Natural convection ventilation of roof by a continuous ridge vent and soffit vents, with air path provided through the blown-in R-30 insulation (appropriate for climate).
• White shingles reduce heat absorption.
• Lower-cost gas appliances.
• Ceiling fans in all bedrooms, living room and dining area.
• Florescent light fixtures in areas where extended usage is likely.
• Programmable thermostats.
• Plumbing fixtures meet low-flow and water saver requirements.
• 12"x12" ceramic tiles throughout the home provide additional thermal mass.
• Roof overhang allows winter natural heating and blocks direct summer sunlight.
• Light-colored exterior paint reflects heat.