Summerhayes graduated from Scotch College in 1913 as dux,[1] and won an exhibition, for Ancient Greek and Latin, to the University of Western Australia (UWA).
[2] Summerhayes served until 1919, including deployment to France; he was awarded a Military Cross in 1918, presented at Buckingham Palace on his 21st birthday:[1] He worked indefatigably both by day and night, frequently exposed to the heaviest fire, to establish a visual and telephonic system of communication for use during a raid.
[1] In the early years of his career, Summerhayes designed residential buildings in the Inter-War Old English architectural style, such as the 1929 "Georgian" residence in Dalkeith, for Malcolm Plaistowe, the 1936 "Interlaken" house in Mosman Park for Mrs I.B.
[1] By 1937, Summerhayes had been successful in various architectural competitions, including a flats and professional chambers for UWA, Wagin's town hall, Perth Dental Hospital, Lake Karrinyup Country Club, and in conjunction with sculpture Edward Kohler, an equestrian statue of King George V for Brisbane Town Hall.
[1] Various buildings designed by Summerhayes have been demolished, but one of his prominent works – the bell tower of Loreto Convent, Claremont – was relocated to William Street in 1992.
The rebuilding and restoration project was performed by the Holmes à Court family company, Heytesbury Holdings, supervised by Summerhayes's son Geoffrey.