WC Archive

"LEED Guidelines for a Sustainable Megalopolis"

That would be quite the tome, wouldn't it?

LEED for Houses is a heroic effort, and I think the process of pilot testing will improve it greatly. I already can see a few corrections that need to be made. For instance, the "Home that is Smaller than National Average" standard would inflict a maximum penalty on Amory Lovins' house, even though it's one of the most efficient in the U.S. That doesn't make much sense. Besides, people like big houses. If the structures are fully sustainable, why penalize them? Isn't the point of Viridian Green to dispense with the needless self-flagellation and sacrifice that characterizes conventional environmentalism?

The influence of LEED-ND is already apparent in the first section of LEED for Houses, "Location and Linkages." The full LEED-ND checklist will expand on those concepts considerably. Another LEED-ND standard, Housing Diversity, is based on the TND Design Rating System.

The pilot LEED-ND standards will be released very soon. You can join the LEED-ND correspondence committee by emailing leedinfo@usgbc.org.

Thanks, Laurence.

While the draft guidelines would indeed penalize Amory for the size of his home, his house -- no matter how efficient it is now -- would almost certainly be more efficient if it were smaller. Home size is the #1 determinant of efficiency; a stock smaller-than-average house will outdo a bigger-than-average hose filled with Energy Star appliances and building materials pretty much every time.

See, that's the problem with inflexible standards based on abstractions. What if a house -- even a "positively enormous" house -- uses zero net energy, or is even a net energy producer? That whole LEED for Homes square footage analysis falls apart. And zero/positive net energy houses are just the type that are likely to be applying for LEED ratings. Since LEED for Homes is a standard for individual houses, it seems to me applicants should have the option of modeling energy use directly, rather than the square footage calculation.

It's a bit murky. I strongly advocate small homes, but consider: the size and efficiency should be normalized for the number of occupants. Think of 2 houses, each requiring the same power per unit area (in Btu/square foot, watts/square meter or whatever). The smaller one houses 1 person. The larger one, twice the size, houses 4 people. The larger is more efficient in an important way. This is analogous to transport: a bus, when empty, is less efficient than a Prius, but when full, it's a lot more efficient.

Energy use per occupant, and area per occupant, seem like better metrics. Of course, households fluctuate and houses change hands, so this might be too difficult to measure. I hope that LEED didn't water down their analysis just to make measurement easier.

I don't know why the LEED committee choosed the criteria of the size to be So important but I agree with them. For me this goes in amuch larger view of the house. It has to be small (or not huge at least) because it requires less material it need less surface and it makes less urban spreading

Resources used in building materials should be included in the net energy usage calculations, of course. Again I ask, if the structure is fully sustainable, what's the problem? Are you suggesting we have a shortage of rammed earth or straw bale? I also don't think there's necessarily a relationship between house size and sprawl. There are plenty of "positively enormous" condos and townhouses that are located in central cities and that use less energy than small houses in the 'burbs.