drive for energy-efficient building comes down to a quest for the
so-called tight envelope. In builder lingo, the better a structure keeps
out the wind and the rain, the tighter its envelope.
you can achieve a "tight envelope" while using some kind of renewable,
recycled material, it's all the better.Many new energy-efficient
products enter the market each year, some builders shy away from them
because of higher costs. In many cases, just adding a layer of
insulation or a specially glazed window can increase the cost of
materials by 20 to 30 percent.
most cases, experts in energy conservation argue that more efficient
materials will lead to lower costs of heating and cooling a house, so
the homeowner will recover that money, usually within several years.
you check out the material produced by the Steel Recycling Institute
(SRI), you might want to skip the wood beams when building your next
to the SRI, builders are simplifying the framing process by ordering
customized steel beams and panels to fit each specific design. The SRI
touts the durability of steel in areas subject to high winds and
earthquakes. Further, it reports that while a 2,000-square-foot
(186-square-meter) house requires 40 or 50 trees to build, a frame from
recycled steel would require no more than the material that comes from
six scrapped cars.
least 65 tons (59 metric tons) of scrap steel are recycled every year.
Recycling scrap reduces the energy produced in making the steel by 75
percent, and it saves space in landfills as well.
Insulating Concrete Forms
This is a 60-year-old technology that's enjoying new life with the discovery of its energy-saving properties.
Portland Cement Association, one of the top makers of concrete forms,
defines them as "cast-in-place concrete walls that are sandwiched
between two layers of insulation material." Concrete is poured into
forms that serve as insulation layers and remain in place as a permanent
part of the structure. The technology is used in freestanding walls and
industry-funded study by the Massachusetts Institute of Technology
issued a report in late 2010 that said buildings made from insulated
concrete forms saved 20 percent over the energy consumed by wood-frame
buildings in cold climates such as Chicago.
build with LEGOs? Then you can build a house. That's the philosophy
of Mark Jensen, who supervises the building of straw bale houses for
Native American communities. Straw is a byproduct of the grain
industry that often would be burned otherwise.
to the California Straw Building Association, straw, if kept dry, can
last for thousands of years. Straw bales bond well to stucco and
plaster walls, and they provide good insulation.
bales usually weigh 50 to 90 pounds (23 to 41 kilograms) each, and a
2,000-square-foot (186-square-meter) house needs about 300
medium-sized straw bales for its construction. Although few
jurisdictions account for straw bale construction in building codes,
local authorities manage the construction on a case-by-case basis.