This report summarises the results of an analysis of the costs and benefits of the Warm Up New Zealand: Heat Smart programme. Under the programme, subsidies are provided towards the costs of retrofitting insulation and/or installing clean heating for pre-2000 houses. The benefits that are included in this report are analysed in more detail in three separate papers produced as part of this study that assess the impacts on energy use, health outcomes and producer surpluses, with additional data on employment. The costs of the programme are also assessed in this report and include the costs of the additional insulation and clean heating plus the administrative costs falling on the government. Administrative costs for companies are assessed as part of the report on impacts on industry.
Taking account of the results of previous studies, the cost benefit analysis (CBA) incorporates the following costs and benefits:
The analysis applies to the insulation and clean heating that is estimated to have been installed as a result of the programme, recognising that some proportion of the total number of households that received a subsidy would have installed these products anyway.
The benefits are estimated over the expected duration of those benefits. For insulation this might be a long period, ie. the duration of the house. The duration of a clean heater is expected to be shorter. However, it is likely that, for some houses at least, some proportion of the benefit will not be additional as it is bringing the timing of the installation forward in time, rather being an absolute saving, ie. some of the houses that received insulation or heating under the programme would have purchased it in the absence of a subsidy at some point in the future; this also means some of the costs are also simply brought forward in time. The starting place is an assumption that insulation benefits will last for 30 years 37 and clean heating for 10 years.
Costs and benefits that fall in different time periods are discounted and these are fully discussed in the report.
The following outputs are considered in this report:
Findings and conclusions
The energy study found that energy benefits from insulation were greatest for houses in cooler regions. This result most likely reflects the fact that energy use for heating purposes prior to treatment is greater for houses in cooler areas than for those in warmer regions. There is therefore greater scope for energy savings following treatment for houses in cooler areas.
There are differences between regions in the impacts of insulation and clean heating on metered energy use. The results for Northland and Auckland suggest small reductions in electricity consumption but an overall increase in total metered energy use; elsewhere there are overall reductions in total metered energy use.
Clean heating results in increases in energy use in all regions. The energy study showed, however, that there were positive energy savings for treated houses that already had reticulated gas, in contrast to the result for other houses. Thus energy savings from installation of clean heating may be increased if clean heating is targeted at houses that initially use reticulated gas rather than electricity for heating.
The health impacts study shows clear differences between the effects on low to middle income earners and other households, with significantly larger benefits for Community Service Card (CSC) holders. This result is consistent with prior research that the sick and other at-risk groups are most adversely affected by cold house temperatures. These groups therefore have the most to gain from installation of retrofitted insulation.
The overall results suggest that the programme as a whole has had sizeable net benefits, with our central estimate of programme benefits being 4.8 times resource costs attributable to the programme. Nevertheless, even greater benefits may be achievable through consideration of four targeting strategies:
Cost Benefit Analysis of the Warm Up New Zealand: Heat Smart Programme
Arthur Grimes, Tim Denne, Philippa Howden-Chapman,Richard Arnold, Lucy Telfar-Barnard,, Nicholas Preval and Chris Young
Prepared for the Ministry of Economic Development, New Zealand
Final Report October 2011