SAN DIEGO -- The City Council voted 6-2 Tuesday to allocate $500,000 to Turner Construction and a group of consultants who will solicit bids to build a new downtown library.

The bids will be submitted to the City Council for the final project approval sometime in April.

Councilman Kevin Faulconer, who represents downtown, said the bidding process will give the city a more concrete estimate of what the project will cost before proceeding.

"To know what this project will cost, we need real numbers, not a guess," Faulconer said.

The design now being floated features a nine-story, dome-topped library at Park Boulevard and J Street adjacent to Petco Park. Two stories would be leased by the San Diego Unified School District for a charter school.

Early estimates peg the cost to build the new library at $185 million.

Council members Carl DeMaio and Sherri Lightner cast the dissenting votes.

DeMaio wants to use the $63 million in redevelopment funds set aside for the downtown library for other projects.

With the city facing a projected $179 million deficit in the coming fiscal year, DeMaio said allocating more money toward the downtown library is "like a family that's deeply in debt, that can't afford its mortgage, going out and getting a construction estimate on a whole expansion and remodel of their house."

Lightner argued that with every department in the city being asked to slash 27 percent from their budgets next fiscal year, construction of the new central library could threaten the operation of existing facilities.

"The central library vision may come at the expense of basic city services upon which all of our constituents rely," she said.

Councilwoman Marti Emerald said the civic leaders who have been promoting the idea of a new central library for at least two decades are owed a solid cost estimate.

"With all the investment that's been made and so many years of this, I think that we owe almost a duty to the people who have dedicated so many years and so much money to find out what this would cost," she said.

The money to begin getting bids will come from the Centre City Development Corp., downtown San Diego's redevelopment arm. The City Council previously approved $16.5 million for design, planning and site preparation.

The city has raised about $37 million from private donations to fund the new central library. A $20 million state grant is also on the table. The bulk of the remaining cost would come from redevelopment dollars.