Large homes and McMansions do not just take up land and resources at construction; according to a new study, they have larger carbon footprints. Here is the abstract:
Residential energy use accounts for roughly 20% of greenhouse gas (GHG) emissions in the United States. Using data on 93 million individual households, we estimate these GHGs across the contiguous United States and clarify the respective influence of climate, affluence, energy infrastructure, urban form, and building attributes (age, housing type, heating fuel) in driving these emissions. A ranking by state reveals that GHGs (per unit floor space) are lowest in Western US states and highest in Central states. Wealthier Americans have per capita footprints ∼25% higher than those of lower-income residents, primarily due to larger homes. In especially affluent suburbs, these emissions can be 15 times higher than nearby neighborhoods. If the electrical grid is decarbonized, then the residential housing sector can meet the 28% emission reduction target for 2025 under the Paris Agreement. However, grid decarbonization will be insufficient to meet the 80% emissions reduction target for 2050 due to a growing housing stock and continued use of fossil fuels (natural gas, propane, and fuel oil) in homes. Meeting this target will also require deep energy retrofits and transitioning to distributed low-carbon energy sources, as well as reducing per capita floor space and zoning denser settlement patterns.
More from the study linking energy use, wealth, and housing size:
We find that both household energy use and emissions per square meter vary widely across the country, driven primarily by thermal energy demand and the fuel used in electricity production (“grid mix”). ZIP-code level analysis shows income is positively correlated with both per capita energy use and emissions, along with the tendency for wealth and living area to increase together. City and neighborhood analyses underscore the environmental benefits of denser settlement patterns and the degree to which carbon-intensive electrical grids counteract these benefits.
Bigger homes require more energy to heat, cool, and light. Wealthier people can afford these expenses. Indeed, being able to shoulder all of these costs with a larger home may be a form of conspicuous consumption: “I have enough resources to live in a larger home and maintain it.” Critics of McMansions argue that such homes are meant to impress those who see them, not necessarily great spaces for residents to inhabit.
The study also connects the findings to possibilities for making single-family homes more green. The models work with two options: (1) retrofitting homes to make them more energy efficient and (2) reducing power generated with fossil fuels (“grid decarbonization”). Yet, there are other options to pursue that could help with the situation:
1. Promoting the construction of or the inhabiting of smaller homes. This could range from tiny houses to the “not-so-big home” to smart-sizing or down-sizing. This may require more significant lifestyle changes – cutting on consumption would be difficult – that are too hard for many people.
2. Promoting fewer single-family homes. While they are the basis of suburban life and popular in many other American communities, multi-family housing is more energy efficient. Given the rhetoric surrounding suburbs (such as President Trump claiming Democrats want to abolish suburb), this may not be easy.
3. Promoting less energy use within homes. What if residents used less heat, air conditioning, and lighting? What if they watched less TV and used their phones and computers less? Again, this might require large lifestyle changes that many would find difficult.
4. Constructing newer homes with much stricter energy guidelines, perhaps even net-zero-energy homes or passive houses. Even if these are restricted to wealthier homeowners who can afford the changes, this could help limit the energy use of larger homes. Also, if such homes are viewed by the public as cool or desirable, perhaps these features trickle down.
5. Could wealthier homeowners purchase carbon offsets for their homes? This would allow them to keep their bigger structures while providing funds that could be put to good use elsewhere.
The scenarios in the paper as well as the ones I proposed all require working multiple sectors of society to get to a place where homes, particularly large ones, use less energy.