Architecture and design firm SWA Group has signed a 5,789-square-foot lease at Olmstead Properties’ 381 Park Avenue South in Midtown South, the landlord announced Tuesday. 

The 10.5-year lease for the global landscape architecture, planning and urban design firm will stretch across part of the building’s 12th floor. SWA — which did not immediately respond to Commercial Observer’s request for comment — will relocate from 31 West 27th Street.  

The exact asking rent was not disclosed, but Olmstead did note that asking rent in the building averages $75 per square foot. 

SWA was represented by Janet Liff from J. Liff Co., while Steve Marvin and Jonathan Bock from Olmstead Properties represented ownership in the deal. Liff did not immediately respond to Commercial Observer’s request for comment. 

Meanwhile, Olmstead also announced Tuesday that health care products company On The Right Track Systems, backed by Riveria Investment Group, signed a new lease for 4,157 square feet on part of the 10th floor of 381 Park Avenue South, relocating from 99 Park Avenue. Riveria invested in the provider of proprietary hospital privacy curtains and health care industry track systems in February 2025. The lease runs for seven years and six months.

Olmstead’s Marvin and Bock also represented ownership in that deal, while the tenant was represented by Arash Sadighi and Tyler Ruggieri from Venture Commercial NYC, as well as by Alan Rosinsky from Metro Manhattan Office Space.

Olmstead has been seeing strong leasing momentum at 381 Park Avenue South as well as 373 Park Avenue South, bringing the two properties to about 99,000 square feet of new office and retail leases in the past eight months. Irish-American pub Stout NYC signed a lease for 13,900 square feet at the base of 373 Park Avenue South in May.

“Companies continue to respond to thoughtfully designed prebuilt suites, upgraded common areas and an ownership team that moves quickly. With additional transactions in the pipeline, we’re excited about the continued momentum at both properties,” Marvin said in a statement.

Amanda Schiavo can be reached at aschiavo@commercialobserver.com. 

Keywords: 31 West 27th STreet, 373 Park Avenue South, 381 Park Avenue South, 99 Park Avenue, Alan Rosinsky, Arash Sadighi, Janet Liff, Jonathan Bock, steve marvin, Tyler Ruggieri, J. Liff Co, Metro Manhattan Office Space, Olmstead Properties, On The Right Track Systems, Riveria Investment Group, Stout NYC, SWA Group, Venture Commercial NYC