Friday, November 26, 2010

Greenhouse Gas Emissions from Buildings

A couple of interesting tidbits in the news today: global standards for building emissions appear to be in the works. We don't think a lot about emissions coming from buildings, but as much as 30% - 48% of greenhouse gas emissions come from buildings while 71% of electricity is consumed there. Factoring in energy savings, improvements tend to pay for themselves, but since there are up front costs many improvements are never undertaken. That's too bad because costs are low: this estimate says that it costs as little as $9 per ton of CO2 abated here in the US, and demand reduction measures could halve growth in energy use and cut current use by 29% at no net cost (see page 5 of linked pdf). It's tough to do that when incentives are different from home builders and home buyers: prices go up when homes are made energy efficient, though the owners make the money back over time through energy savings. Simple awareness is a big issue: although buildings can be built according to "sustainable" standards at a cost premium of just 5% here in the US, builders and developers mistakenly believe costs to be about three times as high. Hopefully these and other relevant misconceptions will be somewhat reduced by the new set of guidelines for evaluating the carbon emissions of buildings currently under development by the UNFCCC.

On the other side of the world, building standards are hugely important right now as China is building the equivalent of Japan's existing building area every 3 years. If energy use in those buildings can be kept low, Japanese-style, energy use may be kept to half of what it would be if those buildings follow US practices. The practices aren't listed in this document, but a few I am aware of include hot water heating and home heating habits. Many of the Japanese homes I've visited and lived in had on-demand hot water heating that used little gas. For baths or large scale use, the inconvenience was limited to pushing a button on a thermostat a few minutes before bathing, and for small scale use it usually meant pushing a button immediately before turning on the hot water. Home and school heating patterns are centered on warming individual rooms: the schools I worked at didn't heat corridors or even bathrooms. You may not find the prospect of squatting over "Image the john very enticing, but when the whole room is at about 40 degrees it's a lot nicer than putting your behind on a cold toilet seat!

No one is expecting the US to start heating houses room by room rather than using central heating any time soon, but there is much that can be done here particularly in the building development sector. Overseas, as the epic numbers of homes and business buildings continue to rise in places like China, they can choose the type of culture they develop. Hopefully they'll build in some energy efficiency and actually employ more of the solar and wind power generation capability they're producing.

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