Results Summary

Impact Area

Total CO2e

/ Year

/occupant

% Saved Against

Benchmark

eTool Medal
Embodied Carbon 536 kg CO2e 44% eTool Silver Medal
Operational Carbon – 661 kg CO2e 121% etool_plat_medal
Total Carbon 125 kg CO2e 103% etool_gold_medal

Project features

The key result of the whole of building Life Cycle Assessment is a figure of -124 kg CO2-e per year per occupant. Please note LCA measures impact so a negative number is the ‘beneficial’ side of carbon performance, meaning the design will provide a carbon improvement over its life – Carbon Positive.

It is observed through the LCA modeling that the following areas have the greatest impact to the overall environmental footprint of the building:

Functionality

This assessment is based on an estimated building service life of 115 years and a predicted average occupancy of 3.2 people. Extended predicted design life was a combination of future-proof very high quality design combined with low redevelopment potential from being located on a low density region. Higher occupancy was achieved with 4 bedrooms on a total 131m2 of fully enclosed area.

On site renewable electricity generation

It’s estimated the rooftop 5kW Solar PV system will get replaced four times over the life of the building. However, the substantially reduced “Operational Impact” due to the renewable energy input offsets this increased “Embodied Impact” many times over during its design life.

The main advantage of a solar system in Australia is that it offsets carbon intensive grid electricity. The system will produce excess clean electricity which will generate carbon credits to offset impacts associate with materials and recurring impacts, resulting in a positive whole of building whole of life carbon performance.

Efficient operational energy use

Energy efficiency measures included a building integrated energy monitoring system, LED lighting, reduced and well ventilated fridge space, high efficiency heat pump for water heating (COP up to 4.5) and ceiling fans.

Solar Passive Design

Placement of home, engaging with the local environment, high spec building fabric and glazing resulted in a 10 star thermal performance home, where no mechanical heating or cooling is required. Innovative thermal control was adopted using evaporative cooling walls, sunlight to warm, cool tubes and natural convection.

Materials and Construction

  • Reduced carpet – Industrial Concrete floor with plant based sealer
  • Concrete Replacement: 50% Blast furnace slag. Locally sourced green concrete with recycled aggregate, recycled slag, local sourced sands, Australian cements and recycled water.
  • Replaced window frames: aluminium for timber. FSC hardwood windows with Low e, argon glass.
  • Plasterboard alternatives.  Plywood replaced FC cladding with timber.  Radial Swan reverse board and battens wall cladding.

This assessment was conducted by Tom Beckerling and certified by Gabby Shaw from eTool.