The structural steel has topped out at a new $80 million mixed-use development in downtown Birmingham.

The milestone is a significant step toward completing the 135,000-square-foot, four-story building at 370 Brown St. 

It’s going to be anchored by a new $15 million JPMorgan Chase & Co. office that will clock in at 42,000 square feet. Wealth management and commercial banking services will be offered in the building.

In all, about 235 people from the New York City-based bank’s two existing Oakland County offices are expected to work out of 370 Brown, said Ron Boji, CEO of Birmingham-based developer The Boji Group. The office space is renting for rates in the upper $40s per square foot per year to the low $50s per square foot per year on a triple-net basis, Boji said.

JPMorgan Chase will be moving from 1116 W. Long Lake Road at Telegraph Road in Bloomfield Hills and the Munder Capital Center building at 480 Pierce St. in downtown Birmingham.

In addition to the office space, slated to open in June or July next year after the bank takes possession of it starting in early September for build-out, the development includes 22 residential units that will rent at an average of $6.35 per square foot.

There originally had been plans for 28 units, but Boji said the demand was for larger units by people wanting to lease apartments as secondary residences to complement their single-family homes.

“Users want more space because they are coming out of their space in Bloomfield, Bloomfield Hills and Birmingham,” Boji said. “It won’t be their primary home because they have roots elsewhere.”

The mixture of primarily two- and three-bedroom apartments ranges from about 1,300 square feet to as high as about 2,500 square feet. Two have already been released, and Boji said renters are slated to start taking occupancy in May next year. 

The building, which sits immediately next to the under-construction RH (formerly Restoration Hardware) flagship store, kicked off construction last year after being in the works for years. 

Birmingham-based Saroki Architecture is the project architect while Detroit-based Sachse Construction is the general contractor. Lutz Real Estate Investments, based in Birmingham, is managing and leasing the residential space to tenants, and Boji Group manages the commercial space.

The ownership of the new building consists of Boji; Victor Saroki of Saroki Architecture; Adam Lutz of Lutz Real Estate Investments; David Trott, the former member of Congress and a real estate finance attorney with Trott Law PC in Farmington Hills; and the Rakolta family of the Detroit-based Walbridge Group construction company.