Albedo is the lesser known term related to the "heat island effect" and it is a growing concern for Phoenix. It's also quite measurable. So why don't we set baseline estimates for typical developments' albedo, based on total size and density, and then set variable development fees based on different desired levels.

For example, if a property has x% building coverage + y% landscaping coverage + z% parking, then an overall albedo score could be assigned based on the materials/colors chosen for each component. The effective development fees could then be estimated based on initial plan submissions, and we could incentivize a gradual mitigation of the heat island effect -- appropriate for both high density and low density areas of the city, with the scoring determined as appropriate for each.