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More than 2 billion people around the world live in inferior housing. In such places, polluted water supplies and inadequate sanitation spread fatal disease. Families are trapped in a daily struggle to survive amid substandard, often inhuman living conditions.
Habitat for Humanity helps break this cycle of poverty. Since its inception in 1976, Habitat for Humanity has helped to build more than 200,000 homes around the world providing safe, affordable shelter to over 750,000 people. Habitat for Humanity affiliates across the United States built 5,400 houses last year, putting Habitat for Humanity International at number 16 on Builder magazine’s list of top 100 U.S. builders.
The houses are built with donated time and materials by volunteers, then are sold to needy families for no profit. Each home is financed with affordable, no-interest loans that can extend out over 30 years.
Volunteer and future homeowners labored together in LaGrange, Ga., where 1,000 helpers for Troup-Chambers Habitat for Humanity built 22 homes in seven days using donated materials. Troup-Chambers Habitat for Humanity partnered with the Department of Energy’s Building America program to ensure that each home qualified for Energy Star rating. The homes, which range in size from 850 to 1,252 square feet, have two to five bedrooms and one to two bathrooms and cost between $45,000 and $57,000.
Each home included these key high-performance features:
- R13 batt wall insulation with ½" rigid insulation
- Double-pane, low-e windows; U = 0.39, SHGC = 0.57
- Programmable thermostat
- Heat pump
- Interior air handler closet in two- and four-bedroom homes
- Right-sized mechanical system
- R-30 in attic
- Insulated steel doors
While Troup-Chambers Habitat hired subcontractors to install the electrical, plumbing, HVAC, and flooring, they estimate that the labor force was 60% volunteer. This included volunteers who had never done construction before, so construction techniques had to be simple enough for even novices to follow.
Building America, a USDOE research partnership program, provided technical support to help the Troup-Chambers Habitat achieve Energy Star performance levels. Building America’s Industrialized Housing Partnership was extremely dedicated; they conducted insulation installation classes with house leaders and held meetings on several occasions with HVAC contractors to go through equipment, installation and duct-sealing techniques. They also gave advice on material purchases and decisions.
The importance of air sealing was also stressed to the volunteers. Each house received a continuous wall air barrier consisting of the following components:
- Sill seal between the slab and exterior wall bottom plate
- Rigid insulation sheathing (over OSB) sealed at all seams and edges
- Tar paper window flashing installed shingle fashion to the sides and bottom of the rough opening, then sealed to the rigid insulation and the rough opening with caulk
- Caulk between the window frame and tar paper flashing, applied to each back side of the nailing flange just before each window is set
The attention paid to air-sealing the houses reduces infiltration and drafts, saving energy and improving durability by reducing the movement of humid air through the walls. These air-sealing efforts are good for occupant health as well, since the air paths are also potential "bug paths," and cockroach allergen is among the top 10 allergy and asthma triggers in the United States.
Programmable thermostats allow more accurate control and performance of the HVAC systems in these houses, while double-pane, low-e windows reflect infrared radiation, reduce energy consumption, and prevent carpets and furniture from fading.
Walter Hendrix, who took over as president of the Troup Chambers Habitat affiliate in 2002 after 34 years as a private home builder, said he felt building to Energy Star standards produced a better house without a large increase in construction costs over their standard construction.
"We found no significant increase in materials costs or in subcontract labor costs," said Hendrix. "It’s mainly the attention to detail; it far exceeds the standard practice. Will it cost more? On a typical 3-bedroom house you might realize $1,000 in extra cost. The return to the home owner on that is probably two to three years ."
Troup-Chambers Habitat plans to build 30 to 40 homes per year over the next 20 years as part of Habitat for Humanity International’s 21st Century Challenge, an initiative to eliminate substandard housing in the 21st century.
This information is provided by the Department of Energy’s Building America program, a private/public partnership that develops energy solutions for new and existing homes. The Building America program combines the knowledge and resources of industry leaders with the DOE’s technical capabilities. Together, they act as a catalyst for change in the home-building industry.
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