Big Steps in Building: Change our Building Codes from Relative to Absolute
For at least 3700 years, since the code of Hammurabi, builders of houses have had building codes, a government minimum standard intended to protect the health and safety of its citizens. Possibly in all that time, the majority of builders have considered it the maximum as well- don't do any more or build any better than you have to. Through the energy crises of the 70's to today, energy efficiency standards kept going up, but the amount of energy used in a house went up faster because they just keep getting larger.The average post-war 1950's house was 983 square feet; by 1970 it was 1500 SF; last year it was 2350. Encouraging smaller homes, like smaller cars, would save a lot of energy, but codes applies the same standard across the board. Just as conservation is a resource, everything we use in housing has embodied energy, a carbon footprint and an operating cost; we have to treat them all as resources where we can mine savings of energy and greenhouse gases.
Monster Homes: Enough is Enough
But how? If we keep raising the relative efficiency, costs go up for the people who can least afford them. Perhaps we need an absolute performance standard for building codes, with maximum resources allocated to each house; a standard that a normal family can afford to live with, yet gives builders and homeowners the opportunity to build larger or differently if they want. Lets look at how this affects various resources:
Heating is a resource: Why shouldn't the purchaser of a monster 5,000 footer have to insulate it twice as well as the buyer of one half the size? Let's make the standards for consumption vary according to size to make affordable housing cheaper and larger houses more efficient. Commenter Tom noted in another post: " it's become increasingly clear to me that our traditional building energy codes that only measure RELATIVE EFFICIENCY are just not getting the job done. It's the ABSOLUTE CONSUMPTION of our increasingly obese building stock that is the real issue." He also pointed out that "Marin County now has an interesting "Big 'n Tall" ordinance which states that no new home may use more NET energy than a home that is a maximum of 3500 square feet (basically if you want to build bigger you have to add solar PV to offset). " (Download Marin County bylaw pdf here)
Let's change our building codes to permit a specific amount of energy consumption, period. If you want to build a house twice as big as, say the design consumption of a 2500 footer, you have to double the insulation in the walls or cover the roof with photovoltaics. If you want a six burner professional stove, add some more insulation still.
This shouldn't affect the rich; they can afford the insulation. It will help the poor; small houses can probably have even lower levels of insulation than they do now. It may hurt the middle-of the road suburban McMansions, but they are dinosaurs anyways.
Supersized Houses and People
Cooling is a resource: almost all cooling is electric, and almost every suburban house comes with it standard. Every suburban house also seems to come standard with big jazzy windows that look great on the renderings (and only have small openings for ventilation); open yards without trees, and walls of thin materials that have no thermal mass. Let's have a building code that demands cross-ventilation, control of solar gain and trees- if you want to build a house, make it part of the code to plant big deciduous tree to shade it in the summer. Trees, awnings, a white roof; it doesn't matter as long as the house does not exceed the performance standard set, the maximum tonnage of cooling a house is allotted.
Land is a resource- Building a house is not an isolated event, it happens in a framework of land development and urban planning. Increasing the efficiency of a house by 20% doesn't do much in the larger scheme of things if you build 5,000 square feet an hour's commute from work, and if getting a quart of milk requires a 20 minute drive. It is all a bigger picture- the design of the community, the frontage of the lots, the ability to walk to school or to a decent transit system, these are the things that really influence energy use. Let's have a building code that sets a minimum density for development and a maximum distance to shopping or transit to reduce the amount of land lost and fuel used for transport.
Can Concrete be Green?
Building Materials are Resources- yet our houses are built of cheap, unsustainable and possibly dangerous materials. Let's have a building code that insists on healthy materials, and get rid of formaldehyde and vinyl and VOC laden finishes. Danger increases with concentration and quantity; lets put absolute limits on how much can be allowed per family. The smaller, less expensive house could use the cheaper materials while the monster would have to pay a little more for higher quality, but both would have the same absolute exposure.
Lets make the building code a planning document, encouraging tighter, more efficient designs, walkable communities and smaller, not bigger dwellings. Let's demand cross-ventilation, control on window size, placement and shading to reduce the need for air conditioning. Let's build smaller but build better and build to last.
Let's take the building code and change it from a legal minimum standard for a development industry out of control and make it a guide for what we want to build when we want to conserve all of our resources, not just energy.
This post is based on an article I wrote for On Nature Magazine.