-By Adam Figman

After collaborating for three years on the 530,000 sq.-ft. Building for the Third Century Massachusetts General Hospital, Seattle-based architecture and design firm NBBJ and Cambridge, MA-based Chan Krieger Seiniewicz, a urban design and architecture group, have merged as one. The result will be a team of more than 700 urban designers, architects, planners, and interior designers.

“We were initially brought together with NBBJ when MGH suggested we team up and combine what the client saw as complementary abilities,” says Alex Krieger, founding principal of Chan Krieger Sieniewicz and professor at the Harvard Graduate School of Design, in a statement “As we worked with our colleagues at NBBJ, we realized we shared the same values and studio culture, only on a different scale.”

Chan Krieger Sieniewicz’s office in Cambridge will change its name to Chan Krieger NBBJ, but the team of designers, including the five principals, will maintain their current roles.

NBBJ already has an office in Boston, so this union will build the company’s New England presence. It also has offices throughout the U.S. and overseas in London, Beijing, Dubai, and Shanghai.