As a child his extended family lived in Lake Boga in Victoria and his early education was at Queen’s College in Barton Terrace, North Adelaide.
He then worked in London and travelled widely on the continent until returning to Australia and setting up in practice on Collins Street, Melbourne.
[10] Having moved to Lyons Road himself he started to design houses in the suburb including substantial homes on St. George’s Crescent.
In 1916 The Salon (a publication of the Australian Institute of Architects) featured a house designed by Dennis at 4 Fern Street Pymble for himself and his new wife.
Next door to the Leuralla shops at 99-101 Liverpool Street Dennis designed a three-story building for the Sam Lands retail jewellery store.
Working with Kenneth Ansolm Ooldling in 1938, Dennis designed the Cane-ite building for CSR on the foreshore at Pyrmont.
Emma sold the house in January 1919 and the Dennis family moved to the Inner Western suburb of Drummoyne overlooking the Parramatta River.
Their daughter Elinor Josephine Dennis was born in 1913[30] and she married Lieutenant Commander Philipp Oliver Laelius Owen RAN in 1939.