Cities are experimenting with cool roofs, tree canopy programs, indoor temperature limits, and cooling centers. The National Center for Healthy Housing (NCHH) is mapping what’s actually working — and putting that knowledge into tools other communities can use.

Extreme heat kills more Americans each year than any other weather-related hazard, and renters bear a disproportionate share of that risk. Unlike homeowners, they typically can’t make modifications to their buildings, and they are often concentrated in older housing stock in urban heat islands with limited access to cooling. 

Yet the policy landscape for protecting renters from heat is fragmented and undercharted. Cities are trying different approaches with little systematic documentation of what works, what doesn’t, and why.

NCHH will conduct interviews with city staff, housing and health officials, and community partners in at least five cities representing a range of intervention types and geographies. The research will examine both building-level strategies — cool roofs, weatherization upgrades, maximum indoor temperature requirements — and community-level approaches such as green corridors, tree canopy expansion, and public cooling centers. The project will also look at cities where little formal action has been taken, to understand the barriers that prevent communities from acting even when the need is clear.

The project will produce three public-facing tools: a report documenting city examples, barriers, and best practices; a user-friendly matrix of policy and program options that local officials can use for planning; and a one-page advocacy tool for local champions pushing for adoption of heat protections. A separate internal memo will assess the feasibility of a future quantitative study measuring health outcomes — emergency department visits, hospitalizations — in cities that have implemented interventions, laying the groundwork for more rigorous evidence on impact.

CO2 Foundation aims to support development of practical, transferable knowledge. NCHH’s track record of connecting communities across the country makes them well-positioned to build this framework and help cities do what they can right now to protect renters from extreme heat.