The Green Swing undertook both a life cycle assessment and an energy assessment to determine the energy efficiency and carbon intensity of the buildings. Below are the results.
The overall Life Cycle Assessment result was a saving of 80% compared to the benchmark, a well deserved gold medal. This result is made up of embodied carbon and operational carbon.
Design embodied carbon is 619 kgCO2e per year per occupant. This is a saving of 60% compared to the benchmark. According to eTool this is a extremely good result for this kind of development.
Design operational carbon is 228 kgCO2e per year per occupant, a saving of 91% compared to the benchmark and worth an eTool platinum.
These Green Swing homes will need little to no energy for heating and cooling.
Under the Building Code of Australia (BCA), the designs of proposed homes need to assessed for thermal performance and compliance with the energy efficiency requirements. There are a number of predictive rating software tools accredited under the Nationwide House Energy Rating Scheme (NatHERS) that can be used: AccuRate, BERS Pro and FirstRate 5. These tools calculate heat gains and losses through the building envelope every hour over a year in a particular location, to determine how much additional heating and cooling may be required to maintain human thermal comfort. The tools can also be used to evaluate hourly temperatures within the building if it operates without heating or cooling.
The tools have standardised building occupant behaviour profiles – they can compare the performance of buildings if they are occupied by people who behave the same way. By eliminating the influence of different occupant behaviours, these tools attempt to predict future performance of new or existing buildings. However, because actual occupancy and behaviour vary from the standardised profile, predictive tools are not always good predictors of actual energy bills.
The results of the energy assessments for The Siding, using the BERS rating tool, are below or you can download a copy of the final results.
|Unit 1 – 9.5 stars||Cooling- 2.4 MJ/m2Heating – 5.8 MJ/m2Total – 8.2 MJ/m2|
|Unit 2 – 9.5 stars||Cooling- 2.3 MJ/m2Heating – 4.2 MJ/m2Total – 6.5 MJ/m2|
|Unit 3 – 10 stars||Cooling- 0.9 MJ/m2Heating – 0.3 MJ/m2Total – 1.2 MJ/m2|
|Unit 4 – 9.0 stars||Cooling- 5.7 MJ/m2Heating – 7.1 MJ/m2Total – 12.8 MJ/m2|
|Unit 5 – 9.0 stars||Cooling- 7.5 MJ/m2Heating – 3.8 MJ/m2Total – 11.3 MJ/m2|
|Unit 6 – 9.5 stars||Cooling- 1.1 MJ/m2Heating – 7.8 MJ/m2Total – 8.8 MJ/m2|
|Unit 7 – 9 stars||Cooling- 5.0 MJ/m2Heating – 12.0 MJ/m2Total – 16.9 MJ/m2|
Other measures include:
Renewable energy – each home will have a minimum of 1.5 kW solar PV system and solar hot water system. None of the homes will be connected to gas.
Reduce consumption – energy efficient appliances, LED / low energy lighting, and energy monitoring systems.