As well as being the largest project undertaken by Hansen Yuncken at the time it was built, the Alfred Hospital Main Ward Block incorporated a major innovation in its foundation. The site's sandy geology posed problems because the design called for an excavation to a depth of 10 to 12 metres, but the ground water surface level was at about three to four metres.
Max Hansen said "We used a well point system around the site to suck water out of ground and drain it before excavating narrow, deep trenches with a purpose-built excavator, which were then progressively filled with Bentonite slurry. We then used massive precast panels - we had the biggest mobile cranes in the country at the time - that were dropped into the ground through the Bentonite slurry. Then we worked around and tied the whole lot together, so the bottom formed a solid concrete raft about 2.5 metres thick at a depth of 12 metres. It was designed to settle as it got bigger, and it settled about five to seven centimetres overall. An ordinary steel-framed building sits on top of the raft."