The Federation of American Scientists has been working on the development of energy-efficient housing materials which can be assembled quickly, relatively inexpensively, and with local production. Their focus has been on the use of "Expanded PolyStyrene" (EPS) wall and roof boards with a "cementitious" coating. EPS has some real advantages -- it's easy to work with, long-lasting, and has excellent thermal properties (cutting heating/cooling costs by 50-70 percent in some tests). Last summer, they embarked on a pilot project for Afghanistan. They're also going to be building a model home in Houston. (For those concerned, EPS does not use chlorofluorocarbons in manufacturing.)
Now comes word that a two-story test house (shown to the right) made of EPS clad with cement board (and fit together without wood framing or braces) has passed earthquake testing. But this wasn't just passing minimal structural requirements: the house remained fully intact after being shaken harder than the strongest earthquakes ever recorded. The FAS pages for the housing material includes some images of the EPS panels used, demonstrating both how easily it can be cut and shaped during construction (prior to cement cladding) and just how strong the clad boards are. Check the extended entry for a large image of a full-size pickup truck parked on a suspended EPS board without any significant bending or denting.
A 2004 FAS article gives some cost estimates. Depending upon choices of materials in the construction, a 72 square meter EPS house in Afghanistan would run from just over $1,000 to just under $6,000 total, including labor and capital expenses; the cement-clad EPS design was estimated to run around $3,000. It may not be the least expensive home building material, but it's still fairly reasonable -- and the energy efficiency and structural integrity make a real difference.
EPS panels are now available for construction projects in the US, having passed Uniform Building Code standards; a company called ThermaSAVE has more details.
(Via Ken Novak)
This is a reduced-resolution version of this high-res image at the FAS site.
STYROFOAM is a brandname, gang. There are a number of manufacturers of EPS; only one makes STYROFOAM. I recommend caution using a brandname interchangeably for a particular technology.
Thanks. As it's also the only widely recognized brand of foamed styrene, it's useful for headlines trying to communicate very quickly the topic of the piece.
But to be clear: the Federation of American Scientists does not claim to be using Styrofoam brand foamed styrene material in their walls.
Fans of David Letterman ask: Will It Float?
Now I know what the walls of the green house I'm planning on building in 5-10 years will be made of :)
I lived next to a 60 70's foam house, the house I was living in had a couple foam rooms it inhereted from its neighbor.
Clading the foam in concrete is a really good idea. The primary problem with the foam is its exterior layers start to degrade, not structurally, but visually. The house shows what looks like some extreme age. It got to the point where a pressure washer was necessary not just for the outside of the foam dome, but the inside too.
The other nice thing about concrete layering is you could make a foam house instead of a foam dome as per our neighbors.