‘Then on top of that was the key to the project, the offset cantilevered slab,’ Peter says. Retaining the slab’s structural integrity across the 10-metre overhang was largely due to clever engineering, but it was also constructed for maximum strength from reinforced concrete. ‘We didn’t use a post-form or pre-tensing slab, we just used reinforcement steel and very large bar members. It’s a very thick slab and there’s a lot of steel holding it up.
‘Half of that slab created the roof for the ground floor, then from there we went back to a more conventional building design for the second storey, where the two ends were blockwork all the way up to the roofline, with standard studwork internally and a truss timber roof.’
A key feature of the home’s design is the seamless, curved connect between roof and walls. Visually, there’s no distinction between the two; the house reads as a split pair of rounded-off rectangles. Peter achieved the requisite streamlined finish by devising a special reverse butterfly box gutter system.
‘The key element with the design was to keep everything slimline,’ Peter says. ‘On a traditional box gutter setup you have to run the full length of the roof, the width of the roof, which could be generally speaking about six metres, and on the minimum fall of two degrees you’re creating quite a slope or distance between top and bottom. We halved it, so we only had to work with a minimum fall of three metres, which allowed us to really cut down that parapet.
‘Design-wise it came together really well, we’ve been able to keep the dimensions of the parapets the same from the sides right through to the roof to the bottom floor.’
The fabulous retro curves around the ‘porthole’ windows at the end of the building were created by grinding the blockwork back and filling in with render – simple but effective. ‘The glass installation was probably the hardest at the ends [of the building] because it was a thick piece of glass that we had to push into the opening. That was a little bit tricky.’