Trevor Dannatt was born in London on 15 January 1920. He studied architecture at Regent’s Street Polytechnic, and joined the firm of Maxwell Fry and Jane Drew upon leaving. Post war, he joined the architect's department of London County Council under Leslie Martin, and worked on the design of the Royal Festival Hall for the Festival of Britain, alongside Peter Moro.
Later Dannatt formed his own partnership and would go on to design a range of buildings; from houses to schools to churches. His first significant house was for Prof Peter Laslett in Cambridge in 1958, now Grade II listed. His other listed buildings include Blackheath Meeting House (1971), the Assembly Hall at Bootham School, York (1966) and his work at the University of Leicester (1960-62). Dannatt also produced a range of work for local authorities, designing social housing, children's homes and sheltered accommodation.