This house is a good example of how the site conditions can still result in an extremely energy-efficient home, despite challenging circumstances.

The site has many constraints to account for, including the adjacent train line to the east, the escarpment to the west, an E2 Sensitive Environment, a slope down from south west to north east, and bushfire. With views to the east and a house that wouldn’t quite orient to the north, this house still rates with a very high 8.1 Stars.

The thermal comfort is such that no heating or air-conditioning is used which reduces the energy use, with summer comfort supplemented by using ceiling fans.

Features that work together to make this house energy efficient include; a small building footprint, oriented for winter solar gain, cross ventilation and higher ceilings, internal thermal mass walls increase comfort levels, underfloor insulation to reduce unwanted heat movement in or out of the building, R4.0 ceiling insulation, exterior walls of 400mm straw bale with lime render rated at R7.1, sealing draughts and any penetrations in the floor walls and ceiling. The use of clay and earth renders also creates a breathable wall system which adjusts humidity within the home to be between 40-70 per cent. The windows and doors are double glazed with the frames made from locally sourced timber. Lighting is provided by energy-efficient LEDs and fluorescent lights. An evacuated tube solar water heating system is used for the hot water.

Water harvesting into a 24,000-litre storage tank, grey water recycling and a composting toilet lightens the load on energy use. Grey water recycling helps water the gardens and plants. The composting toilet system means that minimal energy is required for ongoing use or maintenance. Water harvesting is such that the owners are self-sufficient in providing for their drinking, gardening and grey water.

This design and construction has resulted in a home that offers comfortable living, a healthy indoor environment, reduced operating costs and an investment in lasting architecture. It is a worthy winner of the Excellence in Energy Efficiency award for 2018.