Microsoft Corp. plans a multibillion-dollar overhaul of its main campus in Redmond, Washington, adding space for 8,000 more workers and creating areas for collaboration and recreation as the company tries to keep up with growth in hiring and trends toward more open office spaces.

The five- to seven-year plan will knock down 12 low-rise buildings at the heart of the company’s original headquarters and replace them with 18 new buildings, many of them double the height, President and Chief Legal Officer Brad Smith said in an interview. With the added square footage, the campus’ space will be the equivalent of 180 football fields.

Chief Executive Officer Satya Nadella has been trying to shake up work culture at the world’s largest software maker, turning it into a more open and collaborative environment with fewer employees sequestered in closed-door offices. The new design also features a community space for 8,000 to 12,000 people in an open-air plaza and outdoor areas including running and walking trails, sports facilities and green spaces. The company has about 47,000 workers in Washington state.

“We've focused on the cultural transformation of the company. We want to create a workspace that supports the culture we are creating,” Smith said. “A workspace that encourages people to be creative, to work with each other and to learn from each other.”

The buildings will be closer together, and parking that is currently adjacent will be moved underground. Overall, the campus will be designed more for pedestrians and usage of the local light rail, which will reach the campus by then based on the region’s current plan. The project will create about 2,500 new construction and development jobs, Microsoft said.

Downtown Seattle-based Amazon.com Inc. in September said it was planning a sprawling second headquarters in another location, and later received proposals from more than 200 cities vying for the project. Unlike Amazon, Microsoft felt no need to look elsewhere, Smith said. Bloomberg reported in 2015 that the company was considering this campus overhaul.

The changes will replace the original X-shaped buildings where co-founder and former CEO Bill Gates moved the company in 1986, shortly before Microsoft went public. The layout of those buildings is so confusing that employees used to joke that finding an office was an intelligence test to see if you were fit to work at Microsoft. 

“Since I always failed that test myself, I am happy I am now qualified to work here,” Smith said.

One holdover from the original design will be Lake Bill, the small pond at the center of the old campus, whose name pays homage to Gates.