After a period of work in Europe and South Africa (which reportedly included a job offer from Le Corbusier), Fombertaux returned to Australia in 1955. In 1960, Fombertaux joined Austrian émigré Hans Peter Oser, forming the prominent modernist architectural practice HP Oser Fombertaux & Associates. Oser Fombertaux completed a number of high profile projects including the high rise William Bland Centre (1960) on Macquarie Street, Sydney, the Toohey’s Administration Building on Mary Street, Surry Hills (1960) and the BOAC Travel Centre interior on Castlereagh Street, Sydney (1963). Fombertaux, a talented designer, played a key role in the firm.
Having purchased a vacant block on Karoo Avenue, Fombertaux used the opportunity of his own house to explore a grid design of standard construction units within an enclosing steel frame. The house was designed around a grid of 16 steel columns intersected by concrete floor plates that spiral incrementally upward around the central stair. With few room divisions, working, living and sleeping spaces are visually linked across levels.