Water in the tank

Principle 5: Use and value renewable resources and services

Some of the large branches that I put aside from the felling of the red gum found a good home, forming the entranceway to both the garage and front decking. We got a local welder to make up some brakets using old galvanised water pipe from the site, and a metal bar that I'd collected from the brick cleaning. The metal bar slots into both the pipe and the base of the pole, which was cemented into the ground, giving it a stable foundation which was braced from above using box beams. The box beams taper off, giving them a japanese / aussie bush look - just what we were after (my partner is japanese).

The post was measured and cut to size, the slot position marked and drilled out with a long 8mm bit. The chainsaw was used to deepen the hole and even it out.

After carefully marking the position of the box beam, Peter notches out a slot for it to sit using the chainsaw

The tapered box beam in place, with curved box beams connected to it. Cellar to the right.

Galvanised corrugated iron was used for the roofing. The long lengths bent nicely into shape on the roof battens mostly by their own weight. A licensed roofing plumber is legally required to fit the roof and guttering.

The curved roof is both elegant and practical. The roofing was put up in one day, and because of the aerodynamic nature of the design it provides good protection against ember attack during a bushfire. Gaps in boxed eaves are serious problems because embers can settle in them and ignite the roof cavity - having open eaves nullifies that risk. Open eaves are also beneficial during heavy rains, as overflowing gutters cannot run into the house structure.

How a house burns, from David Holmgren's book 'The Flywire House'

Roofing iron arrives by semi-trailer in sheets up to 10m in length, which will span the entire building in one hit.

The bathroom / toilet / greenhouse has a different roofline than the main structure, allowing solar hot water panels to sit directly on the roof. Rafters are reclaimed hardwood wall studs from the original building.


Fascias were pre-painted and set up on props, allowing the roofing to be screwed into place. When the props were removed the overhang has strength enough to stand on. The eaves are open, so there's no risk of fire or flooding in them.

Roof is on, with some guttering fitted to the fascias

Water began filling the tank the day the guttering was fitted

Wrap it up

Principle 2: Catch and store energy

Now that the frame is basically up we can fit windows and begin wrapping the building with reflective foil. The foil is particularly effective in hot climates offering a radiant barrier which reflects heat back out. The foil does not have an R-value itself, that is only fully achieved by a air space of 25mm between the foil and solid surface, in this case corrugated iron.

Locally sourced hardwood battens are used to hold the reflective foil in place, while providing the air gap needed for it to work. A 600mm spacing between battens makes working on the curved roof much easier.

Making sure that no sharp edges protrude is very important to ensure that the foil doesn't tear. Here Peter and Quent take the edges off the end of the box beams.

Second-hand windows in place, roof and south side of the building wrapped.