Norfolk-based the Alan Boswell Group is to expand its head office at Harbour House in Norwich.
The group's human resources manager, Graham Littlewood, said the expansion was prompted by a surge in recruitment, particularly from the Norwich area.
The group has now added more than 40,000 square feet to its headquarters. The extension includes space for its new mortgages division, new offices and training rooms, and an internet café for staff use.
The group said the development of its offices reiterated its commitment to the area.
