Why Building More Apartments is Good for the Planet
Building apartments in American cities is one of the most effective climate strategies available right now. While federal EV incentives are gutted and gas-ban building codes face litigation across the country, apartment construction continues to reduce climate pollution through four channels: less driving, less fossil-fuel heating, less carbon-intensive construction, and less land converted from carbon-storing ecosystems.
In Apartments Are the Climate Solution Hiding in Plain Sight, Alan Durning, Founder and Executive Director of the Sightline Institute, examined how permitting more apartments and middle housing in compact, in-town locations is an affordability win and an underappreciated climate win.
Key Takeaways:
- Electric heating predominance. Choosing an apartment over a house increases a resident’s likelihood of living in an all-electric home by 60 percent — not because of building codes, but because apartments’ shared walls and smaller square footage make electric heating the easier, cheaper-to-install choice for developers.
- Climate pollution reduction. Residents of tall urban apartment buildings typically produce one-third as much per-capita climate pollution as detached suburban homeowners. Residents of middle-housing (i.e., ADUs, duplexes, cottage clusters, etc.) produce about half as much.
- Political feasibility despite limited funding. The entire US pro-housing nonprofit sector spent roughly $40 million in 2023. The nonprofit climate movement spent an estimated $4 billion the same year — 100 times more — even though housing reforms are winning bipartisan support in red and blue states. In contrast, most climate policies are stalled.
Durning draws on the US Census Bureau’s Survey of Construction (1973–2024), covering half a century of data on heating energy sources for all new US dwellings. He supplements this with the Northwest Energy Efficiency Alliance’s 2022 Residential Building Stock Assessment, which surveyed existing residential buildings across Idaho, Montana, Oregon, and Washington. He also draws on peer-reviewed studies and RMI’s urban land-use reform modeling to estimate metro-level and national emissions impacts from infill housing expansion.
The findings confirm the case for treating housing reform as climate policy:
- Apartments are far more likely to be electrically heated. Some 68 percent of all new apartments built since 1973 are heated with electricity, and the share reached 76 percent in 2024, the highest on record. Houses, by contrast, were only 38 percent electric over the same period, rising to 52 percent in 2024. This gap exists across every US region; in the Northeast, a new apartment is three times as likely to be electrically heated as a new house.
- The climate pollution gap between housing types is enormous. When transportation, building energy, embodied carbon, and land use are combined, residents of townhouses and low-rise apartments typically generate half the per-capita climate pollution of detached suburban homeowners; high-rise residents generate one-third. A recent RMI and UC Berkeley Terner Center study suggests that concentrating the next 10 percent of US housing growth within existing neighborhoods could cut national climate pollution from all sources by one to two percent within a decade. A separate earlier RMI analysis found that the scale of impact is comparable to half of the US states adopting California-style EV mandates.
- Pro-housing reform is the highest-leverage climate investment few are making. Pro-housing reform has won in Arizona, Arkansas, California, Colorado, Montana, Oregon, Texas, and Washington, with bipartisan support. In states like Montana and Texas, Republicans are driving the reforms by framing the issue as deregulation rather than climate. Apartment buildings in Southern red states, where building decarbonization codes face the most resistance, are already 96 percent electrically heated, making explicit climate policy largely redundant.
State and local policymakers can treat apartment legalization as a building decarbonization policy, particularly by prioritizing transit-adjacent sites where residents are also most likely to reduce vehicle miles traveled. Climate philanthropies and nonprofits should consider that redirecting even 1% of US climate funding to pro-housing organizations would more than double the sector’s current capacity at a moment when housing wins are achievable, and most other climate strategies are stalled.
The case is straightforward: more apartments means more electric homes, less driving, and less sprawl, regardless of who controls Washington. In a moment when the climate movement is searching for wins, apartments are hiding in plain sight.
Photo by Benoît Prieur, CC0, via Wikimedia Commons