Cambridge will now allow buildings up to six stories to be built in neighborhoods across the city, a plan designed to help put a dent in the region's housing crisis.

The reform, championed by Councilors Burhan Azeem and Sumbul Siddiqui, is one of the most ambitious changes to any city’s zoning in decades.

Cambridge has enacted one of the most aggressive pro-housing zoning measures undertaken by a U.S. city in recent years: It will now allow the construction of four-story residential buildings citywide.

Members of the City Council voted 8-1 Monday night to dramatically revise zoning rules by eliminating single-family zones throughout the city. The change eliminates single-family and two-family restriction zones while allowing townhomes and buildings of up to four stories in all locations and up to six stories on lots larger than 5,