City councillors approved $14.5 million Monday to remake the old Central Square police station into a home for three human services agencies. (Photo: Marc Levy)

The city appropriated $14.5 million Monday to fast-track a makeover of the old Central Square police station for offices holding the Cambridge Housing Authority, Multi-Service Center and Community Learning Center.

The “gut rehab” and reopening will take about three years, City Manager Robert W. Healy estimated, giving the agencies some 25 percent more space than their current rented offices. The authority would get 52 percent of the building, or 22,000 square feet, and the other agencies sharing the rest, or about 19,000 square feet.

The outside of the 5 Western Ave. building, a historical landmark, is protected and will stay essentially as it is, right down to the window bars, Healy said.

While councillors were enthusiastic about the project, some also surprised Healy with wariness over its speed.

Councillor Leland Cheung hoped for a breakdown on the significant expense, to which Healy acerbically replied that he had a level of detail from two cost estimates of the work that he “thought perhaps mistakenly the City Council didn’t necessarily need to delve into … all these numbers have been broken out with great detail.”

He rattled off some of the estimates of cost per square foot to demonstrate their intricacy and tedium. He also noted that the budget included $1.5 million in contingency funds, since such exhaustive work on an old building was sure to hit snags.

Councillor Craig Kelley focused his questions on building in an environmentally conscious way and was brushed back by Healy and his deputy, Richard Rossi, who said this building was just like other city projects: Money needed to be approved to hire a designer to make sure the building was designed to be environmentally conscious, not the other way around. That was how it worked on other recent reconstruction, including the Cambridge Main Library, Rossi said.

Part of Cheung’s concern was whether the city could be missing out on other opportunities for the building. Fellow councillor Ken Reeves said there had been several private buyers interested in the space, which is just a block from Central Square’s key intersection and a block from the T stop, albeit short on parking spaces.

Healy, though, portrayed the building as something of a white elephant, saying, “I don’t know there’s any hue and cry for reuse of the building. It’s been empty for a year and half.”

Police moved to 125 6th St., the Robert W. Healy Public Safety Facility, in 2008 after 75 years in the Central Square building.

Its prime location had councillors Henrietta Davis and Denise Simmons urging a look at creative uses for the ground floor, including public meeting space, but Marjorie Davis doubted there was a point, given how little space the building has as a whole and how many empty storefronts already afflict the square.

“Ground-level retail?” Decker asked. “Let’s be realistic.”

She praised the plan, saying, “No buts here, this is an excellent project,” and Tim Toomey summed it up as “a long time coming.”

In the end, the granting of the money was unanimous and fast-track approval given with only Kelley opposed. It allowed the Housing Authority, a full partner in the process, to begin the yearlong design process immediately. Rossi suggested the city managers would be happy to give the council updates on the process.

The fast track clearly had a fan in Mayor David Maher, who earlier in the day had attended a ceremony marking a year since the revamped Main Library opened its doors.

“Planning for the library … began in 1992, 17 years before, and I surely hope we don’t see a repeat of a planning process like that,” Maher said. “We have a wonderful and fantastic public library, but this is an opportunity to fast-track something that I think we all agree needs to be fast-tracked. These are terrific, terrific programs serving folks in the city who are underserved, and it is an opportunity for us to finally act in a very positive and forceful way and for the council to take decisive action.”

The Housing Authority, a noncity governmental agency claiming more than 160 employees and an annual budget of more than $60 million, has offices at 675 Massachusetts Ave. The other agencies are on Brookline Street. The authority will get a 50-year lease at 5 Western Ave., Healy said.