Nashville-based developer Southern Land Co. has tweaked its plan for a condo and apartment tower on the last major building site around Rittenhouse Square to add short-term stays on the floors set aside for rental units.

Southern Land decided to offer stays of as little as a few nights at a time in furnished units within the 48-story tower at 1911 Walnut St. in response to demand for hotel-style accommodations in the upscale neighborhood, development manager Brian Emmons said in an interview Friday.

The company plans to open a sales office in the coming months in nearby 1845 Walnut St. to market the 54 units planned on the floors set aside for condominiums, which are being marketed as the Laurel, Emmons said. Groundbreaking is expected by spring 2019.

Prices will start at about $2.5 million for units occupying a quarter of one of the $300 million building's 8,400-square-foot floors, with full-floor units also available, he said. The building's condo section will have a separate entrance and a separate gym from its 241 short- and long-term rental apartments, he said.

Southern Land has been speaking with potential tenants for the building's 25,000 square feet of lower-story retail space, with hopes of leasing ground-floor space along Walnut Street to a high-end restaurant, Emmons said. New York-based fitness chain Equinox will not be a tenant of the building, as has previously been speculated in published reports, he said.