Facebook is growing its Chicago presence in a big way, making room in its downtown office for potentially hundreds of new employees.

Facebook is adding three floors and around 100,000 additional square feet to its office on Wacker Drive, as first reported by the Chicago Tribune. The new space could hold up to 500 extra employees, according to the newspaper.

A source familiar with Facebook’s plans confirmed the news to Chicago Inno. Facebook is planning to take up floors 20-22 at 191 N. Wacker Dr., the source said, which adds to the roughly 25,000 square feet it currently has on the 28th floor.

The move signals a major Chicago expansion for the social media giant. Facebook told Chicago Inno in March it had around 80 employees.

With all eyes on where Amazon will drop its HQ2, Facebook’s growth here shows that other west coast tech giants see value in investing in Chicago. Google doubled down on Chicago two years ago when it opened its new Fulton Market building, and for more than just sales and software roles. Chicago Inno broke the news in January that Google was hiring hardware engineers for the first time in its Chicago office.

Other popular social tech companies like Twitter, Pinterest, Pandora, Buzzfeed, and even Snapchat have offices in Chicago.

It’s unclear when Facebook will have the space built out and begin adding new roles. It currently has 10 open positions in Chicago on its website, including roles in sales, HR, recruiting, and analytics.

This story first appeared on Chicago Inno