It’s easier for cities to reduce their greenhouse gas emissions through the residential sector than it is through the transportation sector, a new study authored by an MIT professor has found. The primary ability to do so is through better construction practices, not increased housing density, interestingly.
The study findings are the result of an analysis seeking to determine the best ways for local planning policies to either complement the Obama administration’s Clean Power Plan or to make up for its absence. (As it stands, it’s looking less and less likely that the Clean Power Plan will ever go into effect).
“Our take-home message is that cities can do a lot at the local level with housing stock,” stated study co-author David Hsu, an assistant professor in MIT’s Department of Urban Studies and Planning, while also noting that: “In transportation, cities can’t make up for the loss of a national strategy.”
The researchers do note, though, that there’s wide variation with regard to possibilities based on the city — with the potential being much greater in fast-growing cities such as Houston as opposed to older cities like Boston.
The press release provides more: “To conduct the study, the researchers examined economic, environmental, and demographic data from 11 major US cities, then developed models projecting emissions through the year 2030, based on a series of different policy scenarios.
“For instance, to analyze ways of cutting emissions from residential energy by 2030, the researchers modeled a baseline scenario in which housing characteristics remained the same. They also modeled scenarios featuring a variety of changes, including the implementation of new energy-efficient construction standards, the building of more multifamily homes, and the retrofitting of homes to save energy.
“Simply requiring newly built homes to be more energy efficient would reduce residential emissions by an average of 6% by 2030. But requiring existing homes to be retrofitted would yield a further 19% reduction of residential emission, on average, across the 11 cities.”
Interestingly, reducing the number of single-family homes by 25% and replacing them with multifamily units “would have virtually no incremental benefit in terms of reduced residential energy use and CO2 emissions” — apparently owing to the fact that when single-family homes are made more energy efficient, the possible gains from multifamily designs are greatly lessened.
As a final note here, the residential sector currently accounts for around 20% of all US carbon dioxide emissions.
The new study is detailed in a paper published in the Journal of Planning Education and Research.