Los Angeles is among the newest major US municipalities to insist developers include affordable housing in new projects, but builders are saying the new rules will only discourage construction.

Advocates are pushing policymakers around the country to implement zoning requirements that ensure developers set aside a certain number of affordable housing units for residents who otherwise wouldn't be able to live there, the Wall Street Journal reports. LA’s new affordable-housing requirement impacts projects of 10 or more units that need a zoning or height change, and requires up to 25% of units in rental properties and up to 40% in for-sale projects to meet affordability requirements.

NYC and Seattle passed similar requirements earlier this year, but LA’s initiative goes a step further and sets wage standards for projects. Such measures are often enormously popular—almost two-thirds of LA voters approved the measure last week—but developers are saying the new regulations will discourage them from taking on projects in the city. [WSJ]