While Amazon is looking to set up a second North American headquarters to complement its Seattle mothership, Microsoft is taking a different approach to growth: it’s taking advantage of its existing 500-acre grounds in nearby Redmond, Washington and launching a major revamp of its existing campus.
The scheme will create enough space for a potential 17% expansion of Microsoft’s Redmond-based workforce, accommodating a maximum of 55,000 people, up from the current 47,000 headcount. Microsoft has been in Redmond since 1986, and this is the largest expansion of its campus in over a decade.
The software giant announced late Tuesday that it would begin the five-to-seven-year modernization program next fall. The project will give Microsoft 18 new buildings, along with 6.7 million square feet of renovated workspace in 12 existing buildings (the campus currently has a total of 125 buildings).
On top of that, the firm is promising “$150 million in transportation infrastructure improvements, public spaces, sports fields and green space.”
“It’s an investment that’s good for our employees, good for the Puget Sound community, and makes good sense for our shareholders,” Microsoft president Brad Smith said in a statement. “We are not only creating a world-class work environment to help retain and attract the best and brightest global talent, but also building a campus that our neighbors can enjoy, and that we can build in a fiscally smart way with low environmental impact.”
“Microsoft has always been a great partner, and the city is excited that they will continue to call Redmond home,” Redmond mayor John Marchion said.
One rather important detail missing from Microsoft’s statement is the projected cost of this redevelopment. According to Bloomberg, it will run into billions of dollars, but there doesn’t seem to be anything more specific out there. For reference, Amazon’s planned “HQ2” is estimated to cost over $5 billion.
Fortune has asked Microsoft for a figure and will update this story if it arrives.