Can Plastic Houses Be Green?

Lego houseThis sustainability business can get really complicated sometimes. Although we always like to press for more than “less bad,” in the solutions being offered, with the understanding that less bad won’t be good enough in the long run unless it’s truly sustainable, there are times when we do have to choose between the lesser of two evils.

A good example of this is the recent practice of constructing houses in Kenya out of polystyrene,  otherwise known as Styrofoam, blocks. Proponents of this practice claim that this use of this material reduces the impact on local forests that would otherwise be stripped of wood to feed the building boom that has occurred there since independence. The boom has led to the disappearance of tree cover along with the appearance of numerous quarries. The impact on the ecosystem has been significant.

“There are a lot of mudslides and landslides due to destruction of the catchment areas,” said Eustace Kathuni, an elder in the Upper Eastern Kenyan village of Kiereni. “We had very unique monkeys but not anymore because the migratory corridor was destroyed. There are no fish in the rivers while the African love bird has disappeared.”

The expanded polystyrene (EPS) panels are more affordable than other materials, and they can be purchased a few at a time, which makes it easy for someone like schoolteacher Alfred Kinyua to save up for a new house by accumulating the panels.

The panels consist of two metal faces bonded to an insulating core. They provide high load bearing capacity at low weight, effective and durable thermal insulation, an absolute water and vapor barrier, a tight air seal, long life with little maintenance, and they can be assembled quickly for fast and economical construction.

So there is little question that this is a useful building material that provides an easy and economical means of construction in these areas that can divert demand away from sensitive forests. But is the material itself green?

According to RMAX, Australia’s largest manufacturer of EPS, it is. They claim that based on life-cycle analysis, EPS, which consists of 96 percent air, uses considerably less energy to produce and creates far less pollution in its production than the pulp and fiberboard alternatives that are also used in insulation and packaging applications. They further claim that when used as building insulation, it saves more energy over its lifetime than is required to produce it, making it carbon negative.

However, they fail to mention some of the material’s downsides. The Earth Resource Foundation points out that this petroleum-based material is derived from styrene, a known carcinogen to which prolonged exposure can create a multiplicity of negative health impacts. OSHA guidelines limit worker exposure to 50 ppm. Production of EPS causes ground level ozone, a serious air pollutant. According to the EPA, over 100 million Americans live in areas that don’t meet ozone air quality standards. Polystyrene containers frequently contribute to roadside litter and it is responsible for a significant portion of landfill volume.

While not all of these issues will necessarily arise in Kenya, and while there are clear advantages to its use there, there seems to be an opportunity here for an alternative building panel made from plant based or recycled waste material. This, I would think, could make a good solution to a complex problem even better. There is a company called Agriboard, located in Texas that already makes a panel of this type of of wheat and rice straw. If this kind of panel could be produced locally, using local crop wastes that weren’t already being used for other purposes, that could potentially be an ideal solution.

[Image credit: Eugene Phoen: Flickr Creative Commons]


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RP Siegel
