16 February 2011 – Lloyd Alter, writing in Treehugger asks an increasingly common question in an article it posted this week: what is a green building? Does inclusion of a feature such as green roof qualify? What if the building required intensive excavation and concrete use?
In the case of a design by Tom Kundig in the US, a stunning construction set” deep into the site” requiring portions of the “rock outcropping to be excavated using a combination of machine work and handwork” and needing the contractor to uselarge drills to set the outline of the building, and “dynamite, hydraulic chippers, a selection of wire saws and other hand tools, working with finer and finer implements as construction progressed,” makes the tag green questionable. Read the whole story
In a debate on prefabricated building, Alter writes, in part:
Over at Inhabitat, Bob Ellenberg, an experienced builder and contributor, asks the question. He expresses “frustration with all of the prefab housing companies jumping on the eco bandwagon and claiming their products are green simply because they are prefabricated” and “some of the claims I see being made relative to overall sustainability of prefab houses are overstated and might even be considered “Green-Washing.” At Green Options, Philip picks up the story and asks “How “green” is prefab building, and should it be embraced by those who want a greener building?”
Preston of Jetson Green responds with “The other thing we can’t forget about prefabs is that they look great. There’s a segment of the population that likes the modern look and wants them to be green in a big way.” Here is my contribution to the debate:
Ninety-nine per cent of prefab buildings look like crap, are wall to wall vinyl, use unsustainable materials and leak energy like sieves. From Fort MacMurray to New Orleans, prefabs provide substandard housing for millions who deserve better.
Prefab means factory built housing, which can be anything from RV’s to FEMA trailers to mobile homes to Living Homes. It is a method of building. A tool that can work with bloodstained teak or lovingly harvested FSC timber, with designs stolen from a 1980 plan book or created by a Ray Kappe. Like any building, prefab is as green as its builders want it to be.
I was drawn to prefab not because of green, but because of design. The conventional architect model of business does not work for housing; only the ultra rich can afford great architects, the very rich can afford one of the many hack architects, and everyone else just gets whatever crap the developers want to put on the table. Unlike industrial design, houses don’t get prototyped; every one is a one-off, and many just don’t work very well. As Frank Lloyd Wright said, “Doctors are lucky, they get to bury their mistakes. Architects can only plant vines” Prefab is a way to distribute the work of a talented architect over a larger number of units and give them an opportunity to get it right.
With prefab, designs are repeated, and they get better with practice. Every single glidehouse that Michelle Kaufmann builds is a little more refined, and a little better than the previous. Just like in any other product, one strives each time to waste a little less and squeeze out inefficiencies and cost. Since Michelle believes in good green design, each house is a little tighter, healthier and greener, but most importantly it is available to customers who could not otherwise afford a house built with sustainable materials designed by a talented architect.
Prefab holds the promise of delivering a greener home in less time and perhaps even less money, but it is only as green as the designer and the builder. Michelle Kaufmann, Jennifer Siegel, Leo Marmol, Steve Glenn and Andy Thomson know where their materials come from, how far they have travelled, to what tolerances they are installed. You can call any of them up and buy their green and elegant designs now at a quoted price. Try that with conventional construction.
Some key points are:
- Material waste
Studies in the Canadian construction industry have shown that as much as 30 per cent of materials are wasted through theft, water damage, or offcuts being tossed in the dumpster. In a prefab factory, nothing is stolen, nothing is thrown out, even the sawdust is used for heating. An onsite builder orders materials with a little bit of surplus to cover waste and may not have another job to take it to; in a factory it goes back onto the rack.
Absolutely true, probably 10 per cent more material than in conventional houses. However we are still 20 per cent ahead of the game and it is actually going into the house and making it stronger. I know of cases where a lot is getting redeveloped and the house is taken apart and sold to someone else and is still strong enough to be picked up and recycled on another lot. That is worth something.
- Carbon cost of shipping
Again, true, we have big trucks and escorts and cranes travelling hundreds of miles. For one day, after building the house in the plant in ten days. Most of the workers in the plant live within 20 minutes of the factory. On a conventional jobsite you have workers driving long distances (for country properties I have known carpenters to drive an hour and a half each way) for ten times as long, usually in big honking Ford F150’s. Then they run out of nails and have to run an hour into town. We did a study for a grant application and compared the carbon footprint of a conventional house to a prefab and came up that prefab used one quarter the fuel, primarily because of speed in the plant, reduced man-hours and employees who drove regular cars a short distance to a full day’s work rather than living out of pickups for months.
I agree that there is an element of greenwashing going on, most prefabs are still built of vinyl and formaldehyde and sitting in unsustainable locations dependent on car transport. They are also mostly still trying to mimic the ugliest of conventional construction. But however you look at it, building a house while you are standing in the rain or snow using handheld equipment is going to be slower and less efficient than building in a factory with sophisticated tools.
Read the whole story