Josh’s House

Josh, his family and team have undertaken this project to prove that resource efficient homes can be built at similar cost and time frames to regular houses. These three bedroom, two bathroom family homes will be thermally comfortable year round, without the need for air conditioning or additional heating. They will generate more electricity than they use, and harvest and recycle water.

Sustainable living is a big goal of the project with a common garden designed between the houses to supply fresh food throughout the seasons. What sets this project apart is that they are building two 10 Star energy efficiency rated houses being built and using intentionally conventional building materials and construction methods, so that others can follow their lead.

  • Assessment : December 2012
  • Completion : June 2013
  • Client : Josh Byrne
  • Builder: Highbury Homes
  • Location: Fremantle, Western Australia

Results Summary

Impact AreaTotal CO2e / Year / occupant (kg CO2e)% Saved Against BenchmarkeTool Medal
Embodied Carbon75714 %
Operational Carbon-338111 %
Total Carbon42089 %

Project features

Design life

Josh’s house, should achieve a superior design life than that of the average Perth home which comes down to the following features:

  • High quality design for superior aesthetic quality
  • Has exceptional thermal performance so occupants will be comfortable living in this home for generations to come
  • Being one of two on the subdivided block, it is slightly higher density than the surrounding suburbs so will be a less attractive option in the future for redevelopment.


Josh has focussed on proving that standard, readily available materials and construction methods were used in the project to prove that sustainability doesn\’t need to be bespoke. Having said that, the design is smaller than an average Australian home, but maintains the same functionality. Additionally, the design life leads to better utilisation from the same resources. eTool provided Josh with a long list of recommendations on how the impacts relating to materials can be improved further. Most of these were quantified and are provided in the detailed reports available on the Josh’s House website.

Operational Energy

The great LCA result for Josh’s house was largely secured with exceptional energy efficiency.

Before implementing renewables, a combination of the solar hot water system, excellent thermal performance, LED lighting (and high levels of natural light) along with energy metering dramatically reduced the energy requirement for the home. Each house will  require less than 10% of the energy used by the typical Australian home and save over $2,000 a year in energy costs alone.

Renewable Energy

Josh has chosen at this stage to install a 3kW solar system which will meet all his operational energy needs  – he will generate more electricity than he needs to offset the use of natural gas. Over the expected life of the building, the solar systems (accounting for re-installations) will have a net saving of over 230t CO2e!

Additional Features

  • Solar Passive Design
  • Landscaping with shading and habitat provision with local native plantings
  • Local food production with a shared vegetable garden, home orchard, chickens, composting and a worm farm.
  • Best practice energy efficiency measures mean the houses will only use 40% of the scheme water of a typical Perth house.
  • Permeable surface treatments to allow localised storm water infiltration and paving to direct water into garden beds.
  • Direct diversion greywater systems will provide irrigation to selected areas, as well as rainwater tanks for internal usage, with mains water back up for dry periods.
  • State of the art centrally controlled irrigation system, incorporating both soil moisture monitoring and weather monitoring to maximise water efficiency.

For more information about this project and to follow the progression of the build, visit Josh’s House.

Alternatively please contact eTool to arrange a cost effective assessment or software training to achieve best practice in low carbon building design.

This assessment was conducted by Henrique Mendonca.