Photo: Jessica Christian / The Chronicle

In the midst of an unrelenting housing crisis, Mayor London Breed is turning to San Francisco voters for help in her crusade to “build more housing and build more housing, faster.”

On Wednesday, Breed will announce the launch of a signature-gathering petition for a November ballot measure meant to simplify and accelerate housing production in San Francisco.

It takes an average of nearly four years to shepherd a housing project with more than 10 units through the city’s permitting process, a 2018 study from UC Berkeley’s Terner Center for Housing Innovation found. If voters pass Breed’s measure, it would require the Planning Department to cut that time down to six months.

“Our broken process for approving new homes has delayed and blocked housing from being built for decades, which got us into the housing shortage we face today,” Breed said in a statement.

The measure, dubbed Affordable Homes Now, “cuts through the bureaucracy, meaning new homes can be built years faster than under our current system so that our low- and middle-income residents can actually afford to live here,” she said.

Like the proposal Breed failed to get before voters last year — it was shot down by the Board of Supervisors — the initiative would streamline the planning and permitting process for 100% affordable housing developments. But in an ambitious twist, the new measure would also confer those benefits to market-rate projects that exceed their affordability requirements.

The signature-gathering effort follows the collapse of SB50 last week — state legislation authored by Sen. Scott Wiener, D-San Francisco, that sought to limit the ability of cities to block denser housing near public transit and job centers.

Photo: Jessica Christian / The Chronicle

But unlike SB50, Breed’s measure would not change San Francisco’s existing zoning laws. Instead, it would eliminate much of the subjective decision-making that occurs during the planning process that Breed and her supporters say delays projects. Fights over the superficial aspects of a proposed development can add time, uncertainty and cost to the already expensive task of building housing in San Francisco, the mayor’s office argues.

Should the measure pass, affordable housing projects would be automatically approved if they meet zoning requirements and the city’s litany of building and planning codes. The proposed measure defines “affordable” housing as units for households making up to 140% of the area median income — or just over $172,000 — for a family of four.

Market-rate projects would get that same benefit if developers choose to build more units of affordable housing on-site than what the city mandates — a provision likely to attract the ire of the mayor’s detractors, many of whom are resistant to efforts to ease pressures on, or reduce concessions from, market-rate developers.

To take advantage of the sped-up process, market-rate developers would have to increase the number of affordable units they build on-site by at least 15%. Currently, market-rate projects of 25 units or more must make at least 20.5% of those units affordable. That number increases by .5% each year, until 2028 under current city law.

Peter Cohen, co-director of San Francisco’s Council of Community Housing Organizations, had not yet read the measure, but said it “seemed a little disappointing” that the initiative sought to “lower the goalpost” for affordability mandates compared to what’s currently required by state law. Cohen compared it to SB35, which streamlines projects that hit 50% affordable housing.

Developers would also have to guarantee that all of the workers building the housing are paid prevailing wages, which generally reflect the pay and benefits provided to unionized labor. The city cannot legally require projects to hire only unionized workers.

Photo: Jessica Christian / The Chronicle

Breed’s measure would also eliminate the public’s ability to challenge proposed housing projects by asking for a special review from the Planning Commission. The mayor and other pro-development advocates have long criticized the ease with which projects can be held up by public appeals, even when they meet zoning, planning and building-code requirements.

Last year, several supervisors expressed concern that eliminating those challenges removed an important opportunity for public input into neighborhood planning. The mayor’s office contends that the zoning laws and other building requirements themselves are the product of lengthy public processes, and that the ballot measure is an attempt to avoid constantly having to relitigate them.

By bypassing the board in an effort to get the measure on the ballot, Breed appears to be banking on the notion that San Francisco voters see and feel the effects of the housing crisis differently than most of the city’s supervisors.

Last year, a survey conducted on behalf of the San Francisco Chamber of Commerce found that 79% of 500 respondents thought the city should create a “policy priority to maximize construction of all housing types.”

In a poll conducted for Breed and the measure’s backers and obtained by The Chronicle, 69% of 600 respondents said they would support a measure to expedite 100% affordable housing and market-rate developments that build more than their required affordable housing on-site. Another 24% opposed the measure and 7% were undecided.

“I don’t know when the Board of Supervisors is going to wake up and realize that the status quo has failed San Francisco when it comes to housing. The board is completely out of touch when it comes to the changes that San Franciscans want to see,” said Todd David, executive director of the Housing Action Coalition.

“Residents want new housing built and they want it now,” he said.

Breed has already secured the support of an influential and politically active labor union: the Carpenters Local Union 22, which boasts around 4,000 members in San Francisco alone, said Peter Garza, the union’s political representative.

The signature-gathering operation will be an expensive one. Breed and her supporters need to present just over 50,000 validated signatures to get the measure on the ballot. That means collecting somewhere between 70,000 and 75,000 signatures, to account for those that the elections department can’t verify. It will likely cost between $500,000 to $750,000 for the signature-gathering petition.

And after that, the mayor is likely in for a tough fight against a coalition of supervisors and advocates who’ve repeatedly fought her housing proposals, broadly on the grounds that they’re too friendly to developers whose profit-driven motives are seen as a central cause of the state’s housing crisis.

Breed and the board both championed a $600 million affordable housing bond that voters passed last November, but they clashed over attempts to lower barriers for 100% affordable housing and housing reserved for educators. After introducing dueling ballot measures, Breed eventually withdrew her version and backed one introduced by several board members.

“The status quo isn’t working for our city and it isn’t working for our residents — we need fundamental reform,” Breed said.

Dominic Fracassa is a San Francisco Chronicle staff writer. Email: dfracassa@sfchronicle.com Twitter: @dominicfracassa