TAMPA — Standing in a West Tampa parking lot, Mayor Jane Castor pledged Wednesday to increase affordable housing stock in the city by 2027 to keep the state’s third-largest city from suffering the fate of real-estate hothouses like San Francisco and Boston.

In announcing the recommendations of an advisory housing task force, the mayor noted that less than 5 percent of the housing built last year in Tampa met the criteria for affordability.

There is no easy answer to the problem, she acknowledged. But she vowed to partner with Hillsborough County and state and federal government to find solutions.

“Nothing is off the table," Castor said.

To that end, the mayor announced the city would put the 18-acre parcel where she stood out to bid for affordable housing after hearing from residents near the massive West River development, which is slated to replace hundreds of public housing apartments vacated and demolished in recent years.

She said the city would build 20 percent more affordable housing units each year by 2027 along with rehabbing and preserving 100 existing homes annually.

The cost of those goals is still a moving target, she said. And city officials didn’t immediately have specific figures on how many units per year will be built.

“We’re looking at everything. We’re looking at single family homes, small developments that have five to ten units, all the way up to multi-story apartment and condominium complexes. And then even the tiny homes, the container homes. There is nothing we are are not going to explore."

Castor said she’ll be working with the county, non-profits, the Tampa Bay Chamber of Commerce and the private sector to gather data and proceed aggressively.

“We cannot do this alone,” she said.

She also asked City Council members to work with her “even if it’s not popular.” Council members Guido Maniscalco, Orlando Gudes, John Dingfelder and Joseph Citro stood behind her as she spoke.

Other task force recommendations included creating a community land trust to streamline the process of converting city-owned and vacant properties into affordable housing. And the city will revamp land development codes to make it easier to build less expensive housing as well, she said.

Ernest Coney Jr., the chief executive of CDC of Tampa Inc., a local nonprofit builder, said he was encouraged by Castor’s vision and her promise to cast a wide net for solutions.

“It’s really important that we all focus on a common goal,” he said.