June 17, 2016, Curbed San Francisco
This green prefab abode, which took only weeks to build, is make of steel and uses soy-based foam for insulation.
In the best way possible, Stanford professor Mark Jacobson‘s new house is like a giant Erector Set, snapped together in less than a week on an irregular, pie-shaped lot near the university. It’s a 3,200 square foot modular home, and the frame is made entirely of steel.
Dr. Jacobson, head of Stanford’s Atmosphere and Energy Program, says he didn’t want to build a new house, but nothing on the market right now was quite up to his standards insofar as green building goes. So he called BONE Structure, a Canadian prefab homes company that opened a San Francisco office last year, to see if they could do better.
The house is designed with zero emissions, operating off of solar panels on the roof and storing juice in an enormous lithium battery designed by Tesla Motors. If it works right, it will use no consumer electricity at all, making it a passive house.
The steel frame is made from 89 percent recycled material. BONE’s sales pitch is that, although the parts are all manufactured in Canada (delivery takes five or six weeks), the clip-together design means that you can customize the size and layout of the house, rather than picking from prefabricated rooms.
Putting the frame together took less than a week. Another week was spent spraying it with a soy-based foam that, once dry, should provide an airtight envelope that insulates and keeps the steel from shrinking or contracting with the weather.
“We’re from Canada. It goes from 100 degrees in the summer to minus 40 in the winter,” explains BONE vice president Charles Bovet. “Ideally, we want the steel never to be in contact with the outside.”
Steel lasts centuries longer than wood, produces less waste during manufacture, and is handily termite proof and fire resistant. Alas, it’s never caught on with most residential homes. Part of that is the fact that it makes a lousy insulator (the soy is supposed to help with such issues), and it’s more expensive. For example, Vallejo’s Blu Homes tells Curbed SF that they used to offer steel reinforced houses, but stopped because of the shipping costs.
It’s also still considered a newfangled idea. “There’s a cultural bias toward wood,” says Isaac Lassiter, CEO of competing modular homes company Cutting Edge. “Every part of America has its native trees, and it’s a product the public is comfortable with.”
Lassiter concedes that steel has some natural advantages as a building material, but without a big demand, he says there’s not much incentive to invest in it.
Opinions vary. BONE thinks they can find a niche, and the professor’s home (possibly the first fully steel frame house in California) is their showcase. The truly curious can schedule a tour next weekend and test its metal for themselves.