A Missouri-based construction engineering firm with roots in Detroit has tripled the space in its downtown office as it prepares to double its staff in the next two years.

Burns & McDonnell, which opened the office in 4,000 square feet at 2111 Woodward Ave. in January, has taken an additional 8,000 square feet.

The company has a three-year lease for the original second floor and extra eighth-floor space of the Francis Palms Building that houses The Fillmore Detroit. The building is owned by an entity of developer Charles Forbes.

Benjamin Nabozny, who heads the office, expects to add more than 20 employees over the next two years and 100 in the next five years. The firm seeks to fill engineering, technician and construction and project-management roles, among others. Burns & McDonnell expects to expand its global workforce by 1,000.

The Detroit office serves as the transmission and distribution center for the construction, design and build company, Nabozny said. The office works on community infrastructure such as updating electric grids with renewable resources along with other facility improvements, he said.

Nabozny declined to disclose the company's clients, but said they include the automotive, restaurant, retail, aviation and utility industries.

"Detroit is growing and thriving in key industries with a focus on the future," the Detroit office leader said in a news release. "As a Detroit native, I'm especially passionate about contributing to the development and success of our city. We're immersing ourselves in helping our clients expand and upgrade critical infrastructure in the region, while adding local, top talent to our diverse team of professionals."

Burns & McDonnell employees gain ownership once hired into the company, which got its start in 1898, through its Employee Stock Ownership Plan. This ownership model is what's driving its growth, Nabozny said.

Interest in the company differs by position. An employee's stock in the private company grows as he or she advances in the firm.

"I always tell people we have our employee hat and our owner hat. You're making decisions as if it's your own company," he said in a phone interview. "That's what really made the company successful, especially in Detroit."

Last year Burns & McDonnell pulled in nearly $3 billion in revenue.

The Detroit office of Canadian real estate agency Avison Young Inc. negotiated the lease for Burns & McDonnell.