The Sonoma County Board of Supervisors has voted to relocate the county headquarters to downtown Santa Rosa by 2027, a move that could cost the county as much as $55 million a year.

The decision to move was prompted by rising operation costs and lack of expansion options at the current location in northern Santa Rosa. In a 4-1 vote at its July 27 meeting, the board approved moving forward with a new site located on 7.4 acres at the former Sears Auto Center in the Santa Rosa Mall.

Two other options had been proposed: staying at the current site or moving to a combined site already owned by the city of Santa Rosa.

Prior to the meeting, the county’s General Services Department conducted a site evaluation and cost feasibility study and concluded that rebuilding on the current site — a project estimated to cost between $37 million and $46 million per year for 30 years — was the fastest and cheapest option for the county.

The Sears site was the second-most expensive option due to the $20.75 million acquisition cost and the price of leasing parking in the Santa Rosa Mall.

However, the move will also recuperate some money from no longer having to lease additional space because of the current location’s constraints. The new location also offers closer proximity to a SMART train station and the rest of downtown Santa Rosa.

Supervisor David Rabbitt, the lone dissenting vote, primarily opposed the new site because he felt the financial ramifications of the move had not been properly discussed.

“The first thing you do when you go buy a house is usually to get pre-approved for a loan,” Rabbitt said. “What we did was say, ‘What would I like to buy?’ and go pick the priciest area downtown … I just worry that we’re going to own an empty lot in downtown Santa Rosa for a product that we can’t necessarily build on.”

In the current plan put forward by the county, 30 percent of employees would work remotely, and some employees in departments such as the Sonoma County Sheriff’s Office and District Attorney’s Office would not relocate to the new site.

Before the sale, the Sears site seller has agreed to demolish the buildings currently occupying the space on which the county plans to build an 18-story office tower, among other buildings. Construction isn’t slated to begin until winter 2025.