Amazon.com continues to gobble up space around its South Lake Union headquarters in Seattle. The fast-growing company has agreed to lease 817,000 square feet of office space now under construction at the so-called Troy Block.

“We’ve agreed to lease the Troy Block and we’re really excited to continue growing our urban campus in the heart of Seattle,” John Schoettler, Amazon director of global real estate and facilities, told GeekWire in an emailed statement. The news was first reported by The Daily Journal of Commerce.

The project is split between a north tower — 422,000 square feet — and a south tower — 395,000 square feet. It is being developed by Touchstone, with one tower set to open next year and the other to follow in 2017. The building is located east of Amazon’s current offices in South Lake Union, and just north of the former headquarters of The Seattle Times.

The Troy Laundry Building was built in 1927, housing the Troy Laundry company. The brick facade of the building is still standing along Fairview Avenue, and will be incorporated into the design. The building received landmark status in 1995, with the city historic preservation officer writing at the time:

Amazon.com’s appetite for office space continues to balloon in Seattle, changing the dynamic of the South Lake Union and Denny Triangle areas.

We’ve agreed to lease the Troy Block and we’re really excited to continue growing our urban campus in the heart of Seattle.

Amazon is currently constructing a 3.3 million square foot project in the Denny Triangle area of Seattle — just north of downtown — that has been dubbed the largest construction project of its kind in the city.

Amazon also plans to build one 24-story tower and another 6-story building on the block between Seventh and Eighth avenues, and Bell and Blanchard streets, adding another 778,000 square feet of space. That area is now home to the Hurricane Cafe, a Budget Car Rental office and a Cornish College of the Arts residence hall.

Amazon does not break out its Seattle area employment, but its worldwide headcount continues to swell. At the end of 2014, the company employed 154,000 people, which includes workers in its network of fulfillment centers across the globe. The Puget Sound Business Journal estimates that Amazon.com will have enough office space in Seattle by 2019 to house more than 70,000 employees.