Elsie Owusu, previously of Elsie Owusu Architects, has taken up the position of director at the London office of the practice.
Other directors at the office believe that Owusu, a long-standing member of the Society of Black Architects, will increase the firm's work in the housing sector.
She has previously worked on a large number of projects, including a massive masterplan for the regeneration of Accra, the capital of Ghana ( pictured below).
In 2003 she was awarded an OBE for services to architecture. She has also sat on the boards of the National Trust and the Arts Council of England.
The reasons behind Owusu's decision to move are as yet unclear.
Feilden and Mawson, which has just moved into a new office in Somerset House, recently hit the headlines after it jointly won the commission to work on the new Supreme Court building.
Working with Foster and Partners, this project involves the conversion of the Middlesex Guildhall on Parliament Square in Westminster.
Elsie Owusu joins Feilden and Mawson in shock move