The recent post on passive houses sparked an interesting discussion about the costs of ultra-efficient homes. Passive houses are meant to be affordable — that is, the incremental construction costs pay back in energy savings in a fairly short time period — but those relative cost calculations really only apply in a European context. Germany, the birthplace of the passive house, has much stricter building codes than in the U.S., so all houses tend to be more expensive.
Assuming the U.S. someday has a functioning housing market, what hope is there for budget-constrained, green-minded buyers? Feast your eyes on the 100K House, “an attempt to build a modern and green home in Philly for $100,000 in construction costs.”
The 100K House is not, I hasten to note, a passive house or even close to it. Rather, it’s an experiment in building a LEED Platinum-certified home on the cheap, with an eye toward demonstrating both feasibility and consumer demand before rolling out the program more broadly. The 100K House incorporates a lengthy list of environmental features, from drought-tolerant plants to enhanced energy efficiency. It does not, however, allow you to throw away your furnace:
> The three biggest factors that make the 100K House a top notch “green home” in our eyes is the dense urban location, the smaller than average size and the superior envelope that doubles code requirements. The home is 50% more energy efficient that [sic] a code home, will provide a much healthier indoor air quality, will use less than half the water of a standard home, creates almost no waste in building and uses sustainable materials where possible.
Construction of the 100K House is actually cheaper on a square foot basis than standard new homes in Philadelphia. Developer Nic Darling lays out his thoughts on how they has been able to buck the conventional wisdom that green construction is expensive:
> Builders, successful ones anyway, often have a basic home that they build over and over. They know how it goes together. They can build it quickly and inexpensively, and most importantly, they know it will sell. When they are suddenly faced with the need to “go green,” they are understandably reluctant to make significant changes to the design of their proven house. Location, interior fixtures, numbers of bedrooms and bathrooms, square footage and window placement are all tested and successful specs…
> Rather than redesign the house that has been successful for them in the past, they add solar panels, geothermal systems, high end interior fixtures, extra insulation and other green features. The house gets greener. It gets certified, but it also increases significantly in cost.
Building green from the ground up eliminates those excess costs. (To be fair, the house is also a bit more sparse than typical new homes.) A slightly more luxurious version of the experiment — the 120K House — recently went on sale. Hopefully the experiment will prove a bright spot in a bleak housing market.