Voters in Los Angeles have approved a labor-backed initiative that creates affordable housing set-asides for major residential development projects that need zoning changes and require those projects to adhere to prevailing wage standards.

With all precincts reporting as of early Wednesday morning, 64 percent of Los Angeles city voters said yes to Measure JJJ, well above the required simple majority of 50 percent.

Measure JJJ was put on the ballot by a coalition of unions and affordable housing advocates. It requires that most major developments that require zoning changes would have to set aside as much as 20 percent of the units as subsidized housing for low-income people. It also requires developers to hire workers from local union hiring halls and pay them union-scale wages. And it also provides incentives for developers to build housing near major transit lines.

The Los Angeles Area Chamber of Commerce and other local business groups opposed the initiative, saying it will result in increased building costs that will make projects not financially viable, thereby worsening the region’s housing supply crisis.

Public policy and energy reporter Howard Fine can be reached at [email protected]. Follow him on Twitter @howardafine.