New housing districts are measurably hotter than the ones they replaced

Current situation

Districts built in the past fifteen years have very little permeable surface or mature planting. Summer surface temperatures are visibly higher, and the planning rules that produced the outcome are still in force.

What the city is trying to reach

Evidence strong enough to change the planning rules, and a retrofit approach for the districts already built.

Constraints

• Land in the affected districts is largely privately held