Builders and land use attorneys have joined forces to oppose a Miami-Dade County ordinance that would mandate inexpensive units in new residential projects.

The extra layer of regulation proposed by County Commissioner Barbara Jordan would require 10 percent of all units in single-family, rental or mixed-use projects of 20 units or more to cater to the workforce population. Units are priced for households making 60 percent to 140 percent of the county’s median income, or $28,800 to $67,200 per year.