In 1957, Collins retired as a fellow of the Royal Institute of British Architects and his professional partnership with J. Normal Calton was dissolved by mutual consent; the pair had been trading as Collins & Calton. At this time, Collins was living at 32 Carlton Crescent in Southampton. Collins' retirement, however, did not mean an end to his interest in architecture and town planning, and in January 1962 a letter from Collins, sent from his Carlton Crescent address, was published in the "Journal of the Town Planning Institute".