House on a difficult site

The owners approached us asking “Design us a house. We want to get it approved by council”. Usually, clients ask for a bit more than this. But this was no usual site. It is a steep, south facing bush block. Issues to consider are on site waste water, bushfire risk, tree clearing for bushfire risk management, tree preservation for erosion control, potential koala habitat and passive solar. The owner wanted minimum disturbance to the vegetation but understood that tree clearing was necessary to fit a building on site and consider safety and bushfire regulations.

We designed a small house (recently approved). Council relaxed the 6m setback rule, which greatly reduced impact to the site. The basement level has a concrete slab for valuable flat working & storage space. A compost toilet was used because it requires the least effluent disposal land area of any system. Due to slope, grey water is filtered and distributed via sub surface dripper irrigation. Due to the impracticality of removing trees on steep slopes, the minimum amount of trees have been removed, which means the house is classified flame zone. A corridor of light has been provided, satisfactory for passive solar performance. This is important. Houses surrounded by trees aren’t as lovely as you might think. The persistent shade can become gloomy emotionally. There’s even some thermal mass in the form of a mud brick  front wall. It is on contour and close to the ground, so reasonably practical and cost efficient to build. As the slope falls away, the advantages of lightweight construction are increasingly apparent.

The owners understood the limitations and settled easily into compromises. However, the process still took a long time, over two years. Much of the delay was due to some bad choices I made with consultants, so I’m somewhat wiser there.

Despite this, I think we were the best choice for this work. A multidisciplinary site design approach was essential to solve the interweaving issues of footprint, vegetation, solar access, ecology and waste water.