Gaming company Valve has leased approximately 225,000 square feet in the Lincoln Square expansion office tower that is under construction in downtown Bellevue, Wash., more than doubling the size of its headquarters in the Eastside city.

The long-reported lease was confirmed Wednesday by Kemper Development Co., which is developing the office building. Valve will take floors 11 through 19 in the 31-story, 710,000-square-foot building, and it will move in May 2017.

“This lease puts Valve on the list of the largest companies in terms of office space in downtown Bellevue,” Kemper President Jim Melby said in a statement.

Melby said Valve chose the building because its employees wanted to be near the shopping and restaurants at The Bellevue Collection, which includes the original Lincoln Square and the expansion. Kemper’s expansion of Lincoln Square also includes a second tower with 231 apartments, a 245-room W Hotel, 180,000 square feet of retail, restaurants and entertainment space between the two new towers and 1,150 new parking spaces.

Other tenants include former Microsoft CEO Steve Ballmer, who leased the top floor in the office tower and wealth management and investment firm Stifel Nicolas, which leased the 20th floor. Another tenant heavily rumored to move into the building is WeWork.

Valve launched in 1996, in another Kemper building, Bellevue Place. The company operates the popular Steam online game marketplace and created Dota 2, one of the most popular games in the eSports world, as well as the Half Life, Counter-Strike and Left 4 Dead game franchises. Valve also makes hardware, including the Vive virtual reality headset that it is working on with HTC.

The Lincoln Square expansion is one of three office projects under construction in downtown Bellevue totaling 1.5 million square feet. Before the Valve lease the only big deal completed was Salesforce leasing 75,000 square feet at the 929 Office Tower. In addition to all of the new buildings opening, Expedia is leaving its 500,000-square-foot headquarters in 2019 to move to downtown Seattle, and Valve’s move leaves a 110,000-square-foot hole at its current building, Skyline Tower.

A recent report suggests all this available space may not be an issue. Colliers International said in its second quarter office report that tenants looking for space on the Eastside represent 3.1 million square feet of demand, and many of these companies will look at downtown Bellevue because smaller office markets don’t have a lot of available space.