Warming Up New Zealand: Impacts of the New Zealand Insulation Fund on Metered Household Energy Use

This paper was prepared for the Ministry of Economic Development,

We analyse the impacts on monthly metered electricity and reticulated gas use of the houses retrofitted with insulation or clean heat source under the New Zealand Insulation Fund (NZIF) programme, titled "Warm Up New Zealand: Heat Smart" (WUNZ:HS).

Our study covers the period from the scheme"s introduction in July 2009 to November 2010.New Zealand's energy profile shows that electricity is the most prominent energy source used in residential houses, followed by solid fuels and gas. For residential space heating, specifically, the energy profile identifies that solid fuels are the most prominent energy source used, with electricity and reticulated gas following in importance.

Our study directly measures impacts of WUNZ:HS on total household electricity and reticulated gas use (not just on space heating energy use). We provide a test of whether the impacts on metered energy use differ according to whether a house already uses a non-metered energy source for heating.

Previous research in this area has found that energy and electricity savings are made from retrofitting houses with insulation, but the effects from installing clean heating sources are dependent on a number of factors, such as the type of clean heating source being installed, the source of heating being replaced, temperature, and how households choose to receive any energy savings.