A citywide overlay district will make it easier for developers to build multifamily housing in Cambridge following a 7-2 vote by city councilors.

The zoning amendment allows multifamily projects containing 100 percent affordable units to be built anywhere in the city, including single-family zones.

A Better Cambridge, a group of pro-affordable housing advocates, hailed the vote as a step forward in furthering diversity and equity.

“Not only will the affordable housing overlay be a helpful tool for building more affordable housing throughout Cambridge, the passage of this ordinance also demonstrates the city’s commitment to housing equity,” ABC Co-chair Becca Schofield said in a statement.

The Cambridge proposal dates back to late 2018 and gained momentum this year amid a widening national debate over the role that restrictive zoning plays in maintaining racial and economic disparities.

Some developers have expressed skepticism that the change will have a dramatic effect upon housing production in Cambridge, due to the gap between high land acquisition costs and the lower rents that affordable projects deliver. Median sales prices for single-family homes in Cambridge averaged $1.8 million in August, according to data compiled by The Warren Group, publisher of Banker & Tradesman.

To help developers of affordable housing such as community development corporations compete with for-profit developers bidding on properties, the zoning includes density bonuses such as allowed building heights from four to seven stories for 100-percent affordable projects.

Councillors Alanna Mallon, Marc McGovern, Sumbul Siddiqui, E. Denise Simmons, Jivan Sobrinho-Wheeler, Tim Toomey and Quinton Zondervan voted in favor of the overlay at Monday’s meeting. Councilors Patricia Nolan and Dennis Carlone were opposed.

Carlone and Nolan faulted the city for failing to take more aggressive steps on its own to encourage multifamily production, such as sales of municipal properties, according to a report in the Cambridge Day.