Overland Park ? Engineering firm Black & Veatch Corp. plans to buy its suburban Kansas City headquarters building for $60 million and ad nearly 250,000 square feet of space.

The engineering and construction company announced Monday that it expand its Overland Park headquarters — the largest office building in Kansas — to 850,000 square feet.

Company officials made the announcement at a news conference with Lt. Governor Mark Parkinson and Overland Park Mayor Carl Gerlach.

They described the real-estate transaction and construction as a strong boost to the local economy during a time of increased uncertainty.

“This is a great example of how, even in these tough economic times, companies that are looking to the future can not only survive, but prosper,” Parkinson said.

Black & Veatch CEO and President Len C. Rodman called the plan a strategic and vital long-term decision to expand.

“This agreement allows us to implement at our world headquarters the same types of innovative and sustainable solutions we provide every day for our clients,” Rodman said.