The design for Concord’s new police headquarters would more than triple the size of the current police station on Green Street and carry a construction price tag of $41.3 million, about $3.5 million more than previously estimated.

The Concord City Council is expected to vote on the project this fall. If councilors approve the plan as-is, the project’s total cost, including what the city paid to buy the land, pursue designs and ready the site, would come in at nearly $50 million.

The police department has said that the condition of the current station on Green Street and its size — around 22,000 square feet — hamper functionality and morale and prevent the department from receiving national accreditation.

At the end of 2023, the city agreed to buy land at 4 Bouton Street for $4.1 million as well as the former Concord Insurance building with a new police headquarters in mind. Another $3.4 million was allocated in last year’s budget to design a new police headquarters at the site.

City leaders have favored a retrofit and addition approach that would preserve the 1957 insurance building’s midcentury architecture. To take on the job, they selected Harriman Architects out of Portsmouth, the firm behind police station projects in Manchester and Dover. Its namesake, Alonzo Harriman, helped design the insurance building itself, according to a report by city staff.

“This is a legacy project for their firm,” the report said. “They are excited to have the opportunity to renovate one of their original buildings for a new use.”

Last year, city leaders weighed building a 13,000 square-foot addition to the roughly 39,000 square-foot office building, which they included in their preliminary estimates. Now, their “preferred design” would deliver a 34,050 square-foot addition, bringing the building to a total of 72,828 square feet. This would mean that, by square footage, the new police headquarters could fit nearly three and a half of the current headquarters on Green Street.

The new building would also house the city prosecutor’s office. This construction is the first domino in a series of city building changes that would renovate City Hall, upgrade City Council Chambers and expand in size and geographically consolidate city offices.

Reviewing estimates last year, city councilors believed that constituents would support a major investment in police infrastructure, even as the numbers gave them sticker shock.

A public hearing on the project’s final approval is expected at the Council’s November meeting. Internal demolition on the building is expected to start August 1, construction next April and the building is expected to go into use around the end of 2027, according to the city’s reported timeline.

Catherine McLaughlin can be reached at cmclaughlin@cmonitor.com. You can subscribe to her Concord newsletter The City Beat at concordmonitor.com.