Fulton County commissioners signed off Wednesday on a proposal to spend at least $150 million to overhaul and expand what is already Georgia's largest public library system.

The board did not set how or when they would ask voters to pay for it, though library officials have suggested a countywide vote on a bond in November.

Preliminary numbers show the plan would add eight libraries at a cost of nearly $86 million. Fulton would ask residents to pay another $64 million to renovate or add to existing branches.

Officials emphasized that those numbers could change substantially by next month when commissioners are supposed to decide whether to ask for a bond issue. The estimates don't include land costs, increases for construction costs over time or contingency funds officials plan to add to each project.

Five small libraries would be closed in southeastern and western Atlanta and replaced with larger facilities.

Commissioners supported it 5-0-1, with Robb Pitts abstaining.

"I'm impressed with the report and the plan from end to end," Commissioner Nancy Boxill said.

Pitts abstained after making an impassioned plea to his colleagues to delay the vote until April. He wanted more time to research whether Fulton should accept an offer from developer Ben Carter to buy the Buckhead branch, demolish it and include the property in his redevelopment plan for the Buckhead Village.

The board's vote essentially rejected Carter's plan because his offer was not part of the plan approved Wednesday. The unique branch's contemporary design has divided opinions since it opened nearly 20 years ago.

On Wednesday, several supporters of the design pushed commissioners to spare the building.

"The price offered can't give you what you already have," said Sally Combs of Atlanta. "My vision is to expand the building using the original architects."

David Green, a professor of architecture at Georgia Tech, agreed the building should be preserved.

"It remains among a handful of buildings that put Atlanta on the map for modern architecture," he said.

The program presented Wednesday started with a consultants' study in 2006 and continued last year with a series of 37 meetings throughout Fulton. Library officials added and subtracted facilities depending on that feedback.

In the end, the plan calls for new 25,000-foot branches in Alpharetta, Milton, northwestern Atlanta's Riverside area, near Wolf Creek park in southern Fulton and the Stewart Avenue-Lakewood area in southern Atlanta.

Other new but smaller branches would be built in Chattahoochee Hill Country, East Roswell and southeastern Atlanta.

Fulton would close or end leases at Bankhead Courts, Bowen Homes, Carver Homes, Georgia Hill, Perry Homes and Thomasville Heights.

Even without the building program, Fulton has 34 branches and a yearly budget of more than $30 million. Still, the system often fares poorly in national ratings when compared with Seattle, Cleveland and other major urban cities.

A voter-approved bond issue would have been more difficult six years ago, when a federal jury awarded a landmark $25 million verdict to a handful of white librarians who alleged discrimination. Consultants later found widespread anxiety and fear among employees and the library director was fired.

The current director, John Szabo, was brought on in 2005 to rebuild the system. He led the effort for the building program.