The war on McMansions continues, and Los Angeles is the latest front.  Following a unanimous vote by the City Council, Mayor Antonio Villaraigosa has signed into law an “anti-mansionization” ordinance that will restrict the allowable building envelope of new or remodeled single-family homes in many of the city’s older residential neighborhoods.

Meant to stem the proliferation of “big ugly stucco boxes” that many citizens claim are inappropriately scaled for the streets they inhabit, the measure sets its sights squarely on teardowns and remodeled additions. Under the new law, a home’s allowable square footage will be limited to about half of its lot size, and garages will be limited to 400 square feet. Builders and homeowners incorporating larger setbacks or certain green features will be allowed to increase their total square footage by 20 percent.

“This ordinance is about preserving neighborhood character,” said Councilman Tom LaBonge, who first proposed the measure in 2006. “We wanted to make sure the neighborhoods that we know and love are protected by the proper zoning laws.”

Set to take effect on June 29, the new rules will apply to some 304,000 lots in the  flatlands, where the majority of the city’s single-family detached homes are located. Los Angeles is not the first municipality to enact such an ordinance (it joins hundreds of others nationwide, including nearby Beverly Hills and Santa Monica) but it is arguably the largest, with a geographic footprint spanning 469 square miles and a population pushing 4 million. A sister ordinance, which would impose similar standards in the city’s hillside neighborhoods, is currently in the works.

Opponents of the measure claim that its broad-brush approach penalizes many for the sins of a few, adding that the new limitations will make it harder for families to grow within their homes. Some also fear its implementation will hurt an already faltering housing market, causing a notable decline in property values.

“The city is essentially lowering the potential of more than 300,000 land parcels by shrinking the area in which builders and homeowners can build,” says Holly Schroeder, CEO of the LA/Ventura Chapter of the Building Industry Association of Southern California. “They could have responded with more stringent requirements with regard to setbacks, roof pitch, articulated features on the façade, and other design criteria related to massing and bulk, which are the core issues behind mansionization. Instead they took a citywide zoning strategy that we think will have a lot of unintended consequences and sweep in a lot of parcels that probably don’t need to be governed in this way.”

Learn more about markets featured in this article: Los Angeles, CA.