Concerned that new “McMansion” homes are changing the character of Los Angeles neighborhoods, the Los Angeles City Council moved Wednesday to temporarily restrict development in 20 areas.

The City Council unanimously passed the Neighborhood Conservation Interim Control Ordinance, which put a two-year ban on the size of new, single-family dwellings in some neighborhoods.

The ordinance temporarily limits the size of single-family dwellings in 15 neighborhoods: Valley Village, South Hollywood, La Brea Hancock Neighborhood, The Oaks of Los Feliz, Miracle Mile, Larchmont Heights, Lower Council District Five, Beverlywood, Inner Council District Five, Fairfax Area, Bel Air, Faircrest Heights Neighborhood, Kentwood, Mar Vista/East Venice and Old Granada Hills.

The law also puts a temporary moratorium on the issuance of building and demolition permits in five proposed Historic Preservation Overlay Zones: Sunset Square, Carthay Square, Holmby-Westwood, Oxford Square and El Sereno-Berkshire Craftsman District.

The new rules came amid a “proliferation of out-of-scale developments that threaten the cohesion and character” of neighborhoods, a city report states.

In 2008, the City Council passed the so-called “mansionization ordinance,” which was intended to control the size of new homes in Los Angeles. But loopholes in the ordinance allowed larger homes to rise, prompting passage of Wednesday’s temporary law.

Los Angeles city planners are crafting new zoning codes for development in the city. Updated regulations are expected to be released in about 18 months.

The Los Angeles/Ventura County chapter of the Building Industry Association of Los Angeles, which represents developers and other home building businesses, opposed the new ordinance.

“It supports the loud voices of a few,” Building Industry Association director of government affairs Ezra Gale said in an interview Wednesday. He said the moratorium “unfairly punishes” homeowners with smaller residences and will decrease property values overall.

The ordinance was supported by the numerous neighborhoods groups, including the Bel Air Homeowner’s Alliance. The group said in a release Wednesday that developers are seeking to build the largest homes in the entire country in Bel Air.

“The City Council’s action today was the direct result of the Alliance’s efforts to solve this problem,” Fred Rosen, president and CEO of the Alliance, said in a statement. “We are committed to implementing solutions that protect our community and its residents.”