eTool have “Benchmark” buildings for different primary building uses.  Benchmarks are a weighted average calculation of embodied and operational carbon for the new buildings of that primary purpose.  For example, our residential benchmark reflects the new residential dwelling mix in Australia.  That is, we’ve looked at the national Australian Bureau of Statistics data for new dwellings, determined the mix of low, medium and high density buildings, established a weighted average size of dwelling and then determined the embodied carbon of that size of dwelling.  We have then profiled average energy consumption for new homes, adjusted for the climate region (which affects the thermal performance component).  We have ensured that all energy consumption stats are calculated on building code compliant structural, design and energy efficiency measures.  This gives us a measuring stick against which all new residential premises can be compared, our “Benchmark”.  Ideally we want to reduce the impact in comparison to this “average” for new dwellings.

The obvious question regarding the above approach is that we’re not comparing like for like. For example, how can we compare a detached house to a multistory residential apartment block?.  By using a functional unit of “impacts / occupant / year” we are normalising results to allow comparisons despite wildly varying building sizes, styles, densities etc.  Without the functional unit the eTool benchmark buildings would be useless to compare against.  The power of the functional unit is that it enables all buildings to be compared, thereby the advantages (or otherwise) of totally different housing approaches can be assessed against the “business as usual” approach.

Posted in: Technical