A major multifamily/mixed-use development in D.C.'s booming Capitol Riverfront neighborhood is preparing to welcome its first residents in September.

Tishman Speyer announced Thursday it will begin pre-leasing July 7 for its 818-unit development at 949 First St. SE.

The developer acquired the full-block site in July 2016 for $63.8M, property records show. It began construction in April 2018.

The property is bounded by First Street SE, K Street, Half Street and I Street. It sits three blocks north of Nationals Park. The Capitol Riverfront neighborhood has been one of D.C.'s fastest-growing areas in recent years, with a host of new multifamily, office and retail projects underway.

Tishman Speyer's project, branded as Crossing, consists of two connected buildings. The east building is scheduled to deliver in September with 410 units, and the west building is expected to deliver in December 2021 with 408 units. The buildings will have 13 stories plus a penthouse.

The project is also planned to include 30K SF of ground-floor retail space, for which the developer has not yet signed a tenant. It will have two levels of below-grade parking.

The buildings' outdoor amenities will include a rooftop pool with cabanas, grills and firepits, a penthouse clubroom with a bar and table games, a dog run, four landscaped courtyards and a 6K SF open-air passageway between the buildings.

The indoor amenities include a lap pool and sauna, a shared kitchen and dining room, a music production studio, a library and work lounge, a multipurpose event space, a fitness center, a coffee bar, a children's playroom and a meditation room.

The project was designed by Handel Architects, with Clodagh Design working on the interiors and James Corner Field Operations as the landscape architect. Clark Construction is the general contractor, and Bozzuto will manage the project's leasing.

"We've selected a premier cohort of architects, designers and partners to work toward a specific vision for our future residents — to enable a practical, convenient living experience with wellness and community at the center," Tishman Speyer Regional Director Jeffrey Chod said in a release.