Nikken Sekkei

Nikken Sekkei Ltd. (株式会社日建設計, Kabushiki-gaisha Nikken Sekkei) is a Japanese architecture firm headquartered in Chiyoda, Tokyo.

The company has its origins in a building design company founded in 1900 as part of Japan's Sumitomo conglomerate. Now a private corporation partly owned by its employees, Nikken Sekkei has completed more than 20,000 projects in some 40 countries.

Among other notable projects, Nikken Sekkei was the primary architectural firm for the Tokyo Skytree, currently (2014) the tallest self-supporting tower in the world, and second tallest man made structure of any kind. It is also responsible for the redesign of Camp Nou, the largest stadium in Europe.