The Mercantile Apartments

The Mercantile Apartments brought new life to two National Register-listed landmarks in the heart of downtown Cincinnati. The adaptive reuse project joined the Mercantile Building, built in 1904 as one of the city’s first skyscrapers, with the adjacent Formica Building, constructed in 1970, converting both former office buildings into luxury apartments. KLH provided mechanical design services for the conversion.

The two buildings are connected by a corridor spanning floors 2 through 12, together offering 76,000 square feet of commercial space and 172 units across 38 floor plans — 81 in the Mercantile Building and 91 in the Formica. The historic Mercantile Library, a subscription library founded in 1835, is preserved and expanded on the building’s top two floors. Its place secured by an extraordinary lease: a 10,000-year agreement guaranteeing its presence on that same plot of land until the year 11845, at just $1 per year. Residents also have access to an enclosed parking garage, a fitness center, and an indoor pet run with synthetic turf and a wash station, while a 14th-floor sky lounge and outdoor rooftop deck top off the Formica Building.

Collaborating with Mechanical Services and Design Inc. (MSD) on the design-build project, KLH delivered mechanical systems that balance resident comfort and energy efficiency with historic preservation guidelines. In the Mercantile Building, the KLH design team implemented an efficient water source heat pump system complete with a fluid cooler and new boilers. In the Formica Building, the KLH design team implemented an efficient four-pipe fan coil system that utilizes the Cincinnati district chilled water loop and gas boilers. Both buildings have centralized outside air and exhaust systems ensuring optimal air quality and energy efficiency.

By pairing the building’s classic architectural elements with advanced mechanical systems, KLH played a key role in bringing the vision for The Mercantile Apartments to life.