Two important studies just released conclude that new homes already exceed the state’s ambitious 2020 greenhouse gas emission reductions requirements. The studies show that new homes are not part of the greenhouse gas problem, but rather are part of the solution.
The benchmark for the state’s landmark Global Warming Solutions Act (AB 32) is the home built in 1990, and homes built today are far more energy-efficient. If AB 32’s ambitious goals are to be met, the focus must be on retrofitting the existing housing stock.
The residential sector accounts for only 14 per cent of the state’s total emissions, far behind transportation (41 per cent) and industrial (25 per cent). In a state with nearly 13.3 million housing units, new housing is adding less than one percent to the total housing stock each year, and because the new homes are so energy-efficient, emissions from those new homes make up just one-tenth of one percent of the state’s total annual GHG emissions.
The second of the two studies calculated plug load, house size, water heating, space cooling, space heating, appliances, and lighting, and found that single-family homes built before California adopted an energy code (1983) are responsible for 70 per cent of carbon emissions from the residential sector. Retrofitting existing homes is four to eight times more carbon-efficient and cost-effective than adding further energy-efficiency requirements to new housing.