Image courtesy of ATCHAIN

The most prominent symbol of Union Square’s transformation is getting ready for its first set of residents.

Developer US2 is leasing the first 77 units at its 25-story Prospect Union Square tower, Somerville’s tallest building. Units are being offered on floors three to eight, with listed rents starting at $2,460 for studio units set for occupancy in July.

Designed by Höweler + Yoon, the property includes 18,500 square feet of open spaces including outdoor seating and public art exhibits. Resident amenities include an outdoor pool terrace and lounge and indoor dog run.

The residential tower is located between the MBTA’s new Union Square station and a 194,000-square-foot life science development which also broke ground in July 2021. The building includes 90 permanently affordable units, with completion of all 450 units scheduled within the next eight months.

Median apartment rents in Somerville rose 2.5 percent in the previous 12 months to $1,884, according to Apartment List’s May report.

Led by US2 as master developer with partners Magellan Development, RAS Development LLC, Cypress Equity Investments and Affinius Capital, the Union Square redevelopment includes a total buildout of 1.4 million square feet of  lab/office space; 1,000 residences, 140,000 square feet of retail space, 112,000 square feet of arts and creative spaces, a 175-room hotel and 4 acres of parks and open space.

Last month, another Union Square land owner, Allston-based Hamilton Co., submitted plans for a life science building across Prospect Street from the US2 site. Hamilton Co. proposes a 200,000-square-foot office-lab-R&D building at the corner of Prospect Street and Somerville Avenue.

Editor’s note: This report has been updated to correct the number of affordable units at Prospect Union Square.