Requirement P2.6.1 and JP1, in NCC Volumes Two and One respectively. The specific target of the change is dwelling designs that represent outliers either in terms of excessively high heating load intensity or excessively high cooling load intensity; that is, the 5% of designs with the highest heating/cooling loads in each climate zone. The objective of both options canvassed in this Consultation RIS is that new dwellings are not built with relatively poor summer/winter performance, thereby improving occupant comfort, containing energy demand, and reducing bills, greenhouse gas emissions and peak loads. An additional objective of the proposal is to improve the precision and credibility of policy and regulatory instruments. It is important that instruments are designed to best enable the achievement of agreed policy goals. It is also important that policy makers are well equipped to adjust policy settings in the future to realise evolving policy goals in areas such as energy security, contained energy costs, climate damage from greenhouse gas emissions and increasing the average level of health and wellbeing of the community. Options for Addressing the Problem and Meeting Code Objectives There are two options of approaching the problems related to the current use of combined heating and cooling loads that are assessed under this Consultation RIS. Option A: Regulatory Adjustment (moving to separate NatHERS load limits, plus an information/education program) The first option has two features: regulatory adjustment to current settings so that separate heating and cooling limits would augment the combined limit in NatHERS. The current NatHERS combined limits will remain the metric for determining the energy rating for each climate zone. This feature ensures that the proposed adjustment is not a change to overall stringency. The proposed change is that designs in climate zones that experience both warm and cool weather would additionally have to meet the separate load limits that have been developed by TIC. The new heating and cooling load limits have been developed for several different building types – as tabled in Appendix B. The climate zones that will be exempt from separate heating and cooling load limits are in cool regions (Hobart and alpine areas) along with regions of northern NT, QLD and WA that only experience cool weather in less than 5% of the year. Climate zones in NSW were modelled by TIC; however, this proposal does not apply to NSW on the grounds that the BASIX scheme – which is a state variation to the NCC that replaces Part 3.12.0.1 and J0.2
Summary Results – 2 The results of the benefit cost analysis for Class 2 dwellings reproduce the same pattern as for Class 1 dwellings, and therefore the data is presented in summary form. An overview is provided in Table 13. 13: Summary Results: Benefit Cost Analysis: Class 2 Dwellings: Non-Regulatory Option: Reference Scenario Jurisdiction Units Present Value of Benefits Present Value of Costs Net Present Value Benefit Cost Ratios VIC $'000 $1,063 -$7,798 $8,861 -0.14 QLD $'000 $120 $2,310 -$2,190 0.05 SA $'000 $44 -$353 $397 -0.12 WA $'000 $173 -$831 $1,003 -0.21 ACT $'000 $20 -$489 $509 -0.04 $'000 $1,419 -$7,160 $8,579 -0.20 The reduction in future construction dominate the analysis, leading to a negative benefit cost ratio and a NPV of $8.6 million, but more than 6 times lower than the $53.9 million projected for the regulatory approach (Class 2 dwellings only). Sensitivity Analyses – Class 2 Dwellings As with previous scenarios, the only significant variable for the benefit cost analysis is the incremental cost of construction, but high cost solutions are unlikely to be selected if the measure is implemented on a voluntary basis. Summary – Class 1 and Class 2 Dwellings Combining the above results for the reference case generates the following summary indicators – see Table 14 below. The combined NPV is $13.8 million, and there is a negative benefit cost ratio (-0.44). Table 14: Summary Indicators: Benefit Cost Analysis: Class 1 and Class 2 Dwellings: Option: Reference Scenario Present of Benefits ($'000) Present Value of Costs ($'000) Net Present Values ($'000) Benefit Cost Ratios VIC $2,297 -$6,939 $9,236 -0.33