He was educated at The King's School, Canterbury and at Corpus Christi College, Cambridge, reading Maths Part 1 and then Architectural Studies in 1914.

[3] He married Olive Topham in 1923 and they had two daughters [1] In partnership with Sir Nigel Norman he designed airport buildings at Heston, Birmingham, Jersey, Guernsey, Manchester and Wolverhampton.

According to Louis Barfe: Dawbarn is reputed to have begun his design process by drawing a large question mark on the back of an envelope, indicating that he had no idea where to start.

Soon, however, his "precise and mathematical mind" began to realise that the symbol of his uncertainty represented a good shape for the building, using the tapering site most efficiently, allowing the free movement of equipment, scenery and people and offering scope for further expansion as necessary.

[8] Early in his career, after a study tour of American airports, Dawbarn designed various impressive airport/aerodrome buildings at Heston, Brooklands, Birmingham, Jersey, Guernsey, Manchester and Wolverhampton.