Davis Cos. has acquired a pair of office buildings in Waltham and Watertown in another vote of confidence for continuing rent growth in the suburbs.

The Boston-based developer acquired the 303,460-square-foot 1025-1075 Main St. in Waltham, a multitenant office building, for $52.5 million and 101 Walnut St. in Watertown, the VHB engineering firm’s local headquarters, for $23 million this week.

Davis Cos. plans to build a new lobby and fitness center, add new food services and amenities at the Waltham property, President Jonathan Davis said.

“With rents rising the way they are on Route 128, we felt there was a great opportunity,” Davis said. “We’ll do the things we always do, and really rebrand the property as younger and vibrant and energetic.”

Average class A office rents in Waltham are now in the mid-$40s, Davis said.

Built in 1980 for BayBank offices and later occupied by BankBoston, Fleet and Bank of America, 1025-1075 Main St. is a pair of interconnected office buildings. The largest tenants are Bank of America and Citizens Disability.

Ben Sayles and Coleman Benedict of HFF brokered the deal for seller Gramercy Property Trust, which acquired the property in 2005 for $22.6 million. HFF also arranged acquisition financing.

Davis Cos. has updated such suburban properties as the former Bedford Business Park, which it acquired in 2012 and repositioned as The Xchange at Bedford, and has a similar strategy at One Burlington Business Center and One Cabot Road in Medford.

Waltham already has a steady pipeline of development and repositioning projects for office space. Clarks shoes’ North American headquarters is moving from Newton to the renovated former Polaroid lab building at 1265 Main St., part of a mixed-use development that includes a Market Basket supermarket. Boston Properties is developing the 450,000-square-foot 10 and 20 CityPoint office and retail complex overlooking Route 128 that will be anchored by the 180,000-square-foot offices of footwear manufacturer Wolverine Worldwide.

And in downtown Waltham, Northland Investments built 269 apartments at The Merc at Moody & Main complex which began accepting residents in September.

Davis Cos. also closed this week on 101 Walnut St., the 94,500-square-foot local headquarters of VHB Inc. in Watertown for $23 million. The engineering firm has five years remaining on its lease.

“We’re talking to them about their needs and looking to see if there’s a good fit for a longer term,” Davis said.

David Pergola and Brian Doherty, formerly of DTZ and now with CBRE/New England, arranged the sale for seller Paradigm Properties of Boston.