Facebook has signed a pre-lease for this future Block 5 building in Bellevue’s Spring District. Rendering by NBBJ.

Facebook has signed a pre-lease for another office building in Bellevue’s growing Spring District, the district’s developer announced today.

The social media giant is adding the 330,000-square-foot building known as Block 5 to its expanding portfolio in the Spring District. The portfolio now includes four leased buildings totaling about 1.2 million square feet, plus one property of 400,000 square feet that it owns (the former REI Co-op headquarters). This brings Facebook’s Spring District commitment to about 1.6 million square feet.

Construction of the Block 5 building will begin later this year and is expected to be completed in late 2023, according to an announcement from developer Wright Runstad & Co. NBBJ designed the Block 5 building and Turner Construction will build it.

Facebook has a leased building under construction — Block 6, also 330,000 square feet — that is targeted for opening in first quarter 2023 and is next to the planned Block 5 building. Affiliates of Wright Runstad & Co. and Shorenstein Properties own the Block 5 and Block 6 buildings.

Facebook’s other leased buildings, Blocks 16 and 24, and the former REI headquarters that it owns are completed. The Block 16 and 24 buildings were sold to Brookfield Asset Management in October 2020 and May 2021, respectively, in deals totaling $565 million for buildings approaching 550,000 total square feet.

“Given the dynamic real-estate market in the region, we’re always on the lookout for opportunities to accommodate our growth,” Tracy Clayton, who manages corporate communications for Facebook Seattle, said in an email. “The Block 5 lease was a natural opportunity for us to expand where we already have a presence. We look forward to welcoming our teams to the Spring District.”

The Spring District is a transit-oriented development that will be served by Sound Transit’s East Link light rail extension, which begins service in 2023. The district also includes University of Washington’s Global Innovation Exchange (GIX), which opened in 2017, more than 800 residential units, many public open spaces, and a brew pub leased by Bellevue Brewing Co. scheduled to open in 2022.