Alleviating fuel poverty in NZ through improving the energy efficiency of the residential sector

Abstract

This thesis will demonstrate that fuel poverty in low income houses in NZ can be eliminated by investing in residential energy efficiency while minimizing CO2 emissions to the environment. State houses, which are taken as typical of low income homes in NZ, are used as a case study. The thesis presents the minimum housing upgrade needed to eliminate fuel poverty for various house types (typologies) and climate zones in NZ. The analysis is presented for a 50 year period considering initial and operational cost and CO2 emissions. Fuel poverty is a condition where households would need to pay more than 10% of their household income on all fuel sources in order to keep their house at a satisfactory indoor temperature.

In NZ, compulsory insulation was introduced only during the late ‘70s, which has resulted in over 60% of the current residential stock being built before that time. The Housing New Zealand Corporation (HNZC) provides state housing to more than 60,000 low income households across New Zealand. The majority of these houses were built to basic passive solar design principles and were made of high quality materials, however, over 2/3 of these houses were built before the energy efficiency regulations came into force in 1978 and so the original buildings were constructed without any thermal insulation. A basic retrofit package was implemented over the years to improve the thermal performance of these houses. However, previous research has shown that the basic retrofit package has not been sufficient to provide a healthy indoor environment at an affordable cost.

This thesis uses a thermal modelling package to estimate the level of upgrade needed to provide an adequate indoor thermal environment, for various climate zones in NZ and building typologies, while ensuring that the households spend less than 10% of the household income on all energy demands. The thesis will demonstrate that if pre 1978 state houses are upgraded to the level suggested, then fuel poverty could be eliminated in this sector of society. Tenants would be able to afford to heat their homes with minimum levels of CO2 emissions to the environment. CO2 emissions associated with installing materials and heating the houses are analysed over a 50-year period to assess the long terms impact of the upgrades. The results of the analysis are extrapolated to the national stock.