The award-winning architect, who was tipped as a future RIBA president, was crushed under a tree he was felling on Monday (3 January) in the woods behind his home in Warleigh, near Bath.
Feilden, who was educated at Cambridge and the Architectural Association, was a pivotal figure in the birth of CABE in 1999 as one of the design watchdog's founding commissioners. He also sat on the Design Review Committee.
The Bath-based architect also regularly contributed time and effort to the RIBA, where he sat on the institute's council in the 1990s and headed up research into development on brownfield sites.
In practice, the development of Feilden Clegg Bradley in many ways mirrored the recent rise of the environmental lobby, with Feilden himself acting as something of a standard bearer in architecture for the ecological movement.
Feilden's long-term partner Peter Clegg said the death came as a major surprise for all at the practice. 'Richard was responsible for much of the drive, the energy and the vision of the practice,' he said.
'I have spent half my life in partnership with him, and the personal and professional loss is incalculable. We are dedicated to pursuing the ambitions he held for the practice and seeing his goals achieved,' Clegg added.
Feilden leaves his wife, Tish, and his three children, Jamie, Fergus and Rowan.