This Report provides a companion document to the Code Calculator, a spreadsheet tool developed by Strategy. Policy. Research. that enables users to estimate energy and greenhouse gas savings associated with possible changes to energy performance requirements in the National Construction Code of Australia.
In particular, users of the Calculator can simulate the effects of making changes to requirements for all building classes, and all states and territories, at regulatory windows that are expected to open in 2019, 2022, 2025 and 2028. The user can select options from simple drop-down lists, or input preferred values into key fields to vary default variables.
While the outputs of the Calculator are dependent upon the input values selected, as an illustration, scenarios depicted in this Report show that energy consumption in 2050 could be some 300 PJ lower than under a reference scenario (in which current energy performance requirements continue through to 2050). Similarly, cumulative greenhouse gas savings during the FY2020 – FY2030 period alone could amount to almost 55 Mt CO2-e. The Calculator does not examine the cost-effectiveness of savings.
Savings can be estimated individually for every Code building class and for each state and territory. Also, users can over-ride a large range of default variables, at the level of individual building classes and states and territories, for:
- Building stock growth rates
- Refurbishment rates
- Fuel mix
- Reference (NCC2016) energy intensities
- Coefficients of performance (COP) for electrical and gas space conditioning (residential)
- Average dwelling size
- Greenhouse gas intensities
For residential buildings, savings scenarios can be generated by star rating, in half-star increments, or by percentage changes from the previously-existing standard. For commercial buildings, savings scenarios are expressed as percentage reductions from previous regulatory standards.
The report highlights some important uncertainties that would ideally (and in some cases are already intended to) be the subject of future research:
- The absolute size of the commercial building stock in Australia, in particular, with lesser uncertainties affecting our understanding of the size of the residential building stock
- The rate of refurbishment and demolition/rebuild of all buildings in Australia – which is particularly important in that all ‘new building work’ should comply with the Code, and therefore contribute to anticipated energy and greenhouse gas emission savings
- Evidence regarding the ‘performance gap’ between simulated and actual energy performance of all building types in Australia and, relatedly, the extent of compliance with existing Code energy performance requirements.