A new office building that connects to the Dunwoody MARTA Station quietly opened in the spring, with its owner making an official announcement in August.

Twelve24 is a 16-story mixed-use building located at 1224 Hammond Drive and features office space, retail stores, restaurants and outdoor deck amenities, according to a press release. The building is a development project of Trammell Crow Company and a joint venture partner advised by CBRE Global Investors.

The Twelve24 office tower is 16 stories and located at 1224 Hammond Drive. (Special)

The building opened April 3, said Brandon Houston, a principal at TCC Atlanta office, in an email. Houston said TCC waited to announce its opening because of the COVID-19 pandemic.

Iron Hill Brewery & Restaurant, which is set to open March 2021, will take up 7,500 square feet of the ground-floor retail space at Twelve24, according to the press release. The Delaware-based restaurant will have indoor seating for about 350 people inside and on-site brewing equipment, according to a press release from the company when it signed a lease in November 2019.

The building connects to the MARTA station with an elevated pedestrian bridge. It will soon also be connected to a nine-story Hyatt Place hotel set to open in September, according to the press release.

The 3.94-acre site is located on an unused portion of the Perimeter Mall parking lot purchased from the mall’s owner, General Growth Properties. Trammell Crow also purchased the west parking deck once used by the MARTA station in 2018. MARTA had been leasing it from General Growth Properties but said it was never fully utilized.

“Twelve24 has created a unique offering for the Central Perimeter community, with its combination of high-end office space, transit connectivity, uncommon amenities and retail offerings,” Houston said in the press release.

The building has 334,000 square feet of office space and 11,000 square feet of ground-floor retail and restaurant space, according to the TCC project page for the building.

National staff company Insight Global Insight signed a lease for 175,000-square-foot office space in the new building in January 2018, which relocates the company from its current headquarters in Brookhaven.

Three floors with 90,000 square feet of space remain available for rent, according to the release.

Twelve24 includes a fifth-floor sky lobby, indoor-outdoor conference center, a fitness center and an outdoor yoga lawn.

The building is LEED Certified, which means it meets certain sustainability standards. The building was designed by Duda Paine Architects, according to the release.

The building was approved by the Dunwoody City Council in October 2017 and construction started in August 2018.