The Building Codes
Societal Impact Matrix
Return of The Village
Habitat For Humanity
Curves of Breath & Clay
Overview of Techniques
Nature, Earth & Magic
History of Cob
Cob Q & A
Compressed Earth Blocks
German Clay Building
Earthen Plaster & Aliz
Solar Water Heater
Habitat for Humanity: International Environmental Initiative
Habitat for Humanity International's "Environmental Initiative" promotes housing that takes into consideration the impact of the construction and use of housing on our God-given earth. Internationally, there are many factors governing the types of materials chosen to construct the house. In addition to choosing low-impact materials, we look at ways to reduce the energy and water needed in the houses, as well as reducing transportation and fuel costs through proper site selection.
There are many good examples of environmental construction among our 1,700 affiliates. We have published a few of these as case studies which show the advantages and decisions involved in choosing certain construction methods, materials and energy systems. We work with programs promoted by individuals, organizations, utility companies and government. Some of these programs consider the basics: good amounts of insulation, reduction of air infiltration and the total amount of energy to keep the house comfortable. Others take the next step to include energy used in appliances and space conditioning systems, solar orientation to reduce energy needs, shading to keep the house cool in the summer, southern windows to bring in the winter sun's warmth, increased levels of insulation that save even more energy, and special windows to reduce heat loss or heat gain.
A third set of guidelines include all the above, but require certain amounts of recycled materials, such as plastic lumber from recycled plastics, be used in building. These guidelines also specify certified timber (that is grown and harvested with the lowest possible impact on the environment), no materials containing CFCs or HCHFs, and roofing systems that need less frequent replacement than standard asphalt shingle.
Additional specifications include xeriscaping (the use of native plants and those that require less energy and water for upkeep), planting for erosion control, porous pavements that reduce and slow water run off, planting shade trees to help reduce the temperature in the area, and planting trees to replace the wood used in building the house. Appliances that use very little energy or cooking methods that reduce fuel consumption are recommended. These include wood-burning stoves that are made of rammed earth that reduce fuel needs by 50%, solar stoves, solar electric systems, and solar water and space heating.
Construction methods used have included straw-bale; compressed earth block, some with natural insulation, and others with recycled sand from industrial waste; and rammed earth. Additional design and construction techniques we have used include structural insulated panels, steel frames and roofs, salvaged telephone poles, locally-grown certified timber, composting toilets, natural lighting, natural ventilation, and low-VOC materials used in homes for chemically sensitive people.
Most recently we have developed a system of "materials management." In this system plans are reviewed to reduce the amount of material waste. For example, if a plan had been designed so that a wall was 10'-3" long, we will look for a way to reduce it to 10' so a standard size sheet of drywall would fit rather than having to cut another board. All building elements can be considered with this mind set.
The other part of materials conservation is to divert as much of the waste stream as we can away from the landfill. To do this we have developed a number of recycling techniques: drywall is ground up and applied to the soil under sod, cardboard is recycled, and wood scraps are given to small woodworking shops or ground up for mulch. Food containers that are used by workers can also be recycled. At times 80% of the construction waste has been diverted, which also saves on dumping fees. Homeowners have also been encouraged to continue this practice by composting yard waste.
Habitat "Restores" are also used by Habitat affiliates. Restores are warehouses where parts of deconstructed buildings can be taken for resale. There are also new items donated by companies that may be last year's model, or a discontinued or overstocked item. These are made available not only to the Habitat affiliates but to the public as well. These stores especially help low-income families and rental property owners improve their houses. The sale of these donated items brings income to Habitat to construct more houses, helping other low-income families who qualify for our no-interest loans.
One of the ways we encourage these energy-efficient, earth-friendly homes is through a "Green Team." A Green Team is a group of volunteers that works with their local affiliate. We are trying to get participation of at least one person in each of our affiliates. These volunteers help the affiliate make sure that homes are built to keep the utility bills low for homeowners and that the environmental impact of construction is considered when methods and materials are being chosen.
Some affiliates have reduced the utility bills by thirty percent, which has enabled them to work with families who had incomes that would be too low to qualify for a house that was less energy efficient, even with our interest-free loan. This is a great step toward making housing affordable, so that everyone God has created can have at least a simple, decent place to live.
Wayne Nelson works with Habitat for Humanity's Department of the Environment and is an international provider of construction information and training. Trained as a carpenter and builder, he has particular experience with creating shelters with compressed earth blocks in Africa and other countries.
Construction and Environment Resources
Habitat for Humanity International
121 Habitat St., Americus, GA 31709
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