The $15 million, almost 45,000-square-foot city hall will likely open in April, said Phil Wong, San Ramon’s planning director. At this point, it’s largely a matter of installing lighting, audiovisual equipment and doing concrete work and other last-minute outside items.

“Once we move in, we want everything operable and ready to roll,” said Wong, who expects an opening ceremony to take place in May. Thirty-six workers are expected to be assigned there, he said.

The city hall is being built by Sunset Development Co., essentially in exchange for two land parcels along Bollinger Canyon Road. There’s less square footage for city government than was proposed as part of the big project in 2003 that put city government, apartments, retail and recreation in essentially the same space. The city hall segment had a $40 million price tag at that point.

The cost of the city hall came down by more than $25 million after the original project was deemed too extravagant. Refurbishing the city’s library and keeping some city departments in other places enabled a downsizing with relatively little pain, Wong said.

“It was a situation of what the city could afford to do,” Wong said. The plan was approved in 2013.

Just as the city hall work is finishing up, the $750 million City Center Bishop Ranch project will begin — years later than expected, a bit smaller and with the housing in a different configuration. Demolition of existing office buildings is expected to begin in March.

“We thought the original plan was great; we were teed up and ready to go,” said Alex Mehran Jr., president and chief operating officer of Sunset Development, which owns Bishop Ranch. But things were changing; the recession hit and traditional anchor stores weren’t expanding, he said, and the city hall project had gotten smaller.

“So 635,000 square feet of retail space became 400,000 square feet,” Mehran said.

Jeff Dodd, Sunset’s senior vice president of retail, said about 75 retailers, service providers and restaurants are expected to fill that space.

He said (very) early talks with prospective tenants show they want to be part of a project designed to be more “civic” than a standard shopping center — more social, more part of the community fabric and a unique entity in the East Bay.

“It’s like a ‘public piazza,’ and we’ll have something going on there all the time,” Dodd said.

The retail comes in the project’s first phase, which Dodd said should open in 2018; 487 apartments, a 10-screen movie theater (with full-recliner seating) and 169 hotel rooms are the bulk of Phase II.

Originally directly above retail spaces in the main city center structure, the apartments now will be on land immediately east of the commercial project.

City Councilman Dave Hudson said the new city hall should offer the public — and elected and appointed civic leaders — a more welcoming place to carry out and take part in local government.

On the eve of city hall’s opening, he was simultaneously excited and cautiously reserved. He has been around long enough to see all permutations of the project.

“Thank goodness we’ve finally accomplished something,” he said. “This could be a real downtown for us.”