The challenges faced by homeowners and other stakeholders in retrofitting double glazed windows in older homes in New Zealand

Abstract

Current building legislation (NZS4218:2009) includes requirements for energy efficient windows. This has resulted in most new homes in New Zealand being fitted with double glazed windows, improving the health, comfort and environmental efficiency of these buildings. Yet, a large number of the existing (older) homes built before the legislation, more than one million homes, have not adopted the new technology meaning most people are living in cold, mouldy and unhealthy homes across the country. This suggests barriers to the uptake of double glazed windows (DGW) in existing homes.

Therefore, this research seeks to identify and discuss the challenges faced by homeowners and other stakeholders in retrofitting double glazed windows in older homes in New Zealand. The focus of this research is to analyse the data collected and evaluate the findings with information from the literature and provide recommendations to help deal with the challenges in retrofitting DGW. These recommendations can make retrofitting DGW more accessible to homeowners resulting in healthier and more comfortable homes as well as helping to protect the environment. In order to accomplish the purpose and objectives of this research, this study employed the unstructured interview as a data collection method with a qualitative approach. A total of 12 participants from homeowners and industry professionals related to the retrofitting of double glazed windows in older homes were interviewed in New Zealand.

Based on the empirical results, the study found a number of challenges in retrofitting double glazed windows. The main challenges are attributed to its high cost, lack of information, perceived low return on investment (ROI), difficulty in accessing trades people, uncertainty and length of time frame as well as complexity of regulation. The benefits such as comfort, health and safety and helping to address environment issues and the insignificant economic gains are not enough drive for most homeowners to retrofit their homes with DGW. Furthermore, homeowners find that it is difficult to access information and knowledge associated with retrofitting. It was found that based on the current understanding of benefits and environmental issues, major factors identified as challenges, there is only limited interest demonstrated by most homeowners in retrofitting their existing homes with DGW.

This research provides recommendations that could increase the interest of homeowners in retrofitting their homes with DGW. Firstly, regulation could be introduced as a motivating driver to retrofit DGW in older homes. Secondly, stakeholders should also create a knowledge platform with detailed information on retrofitting DGW such as technology, cost, time frame, process, health, comfort and environmental issues. Thirdly, DGW with vacuum technology should be used as it can match SGW in terms of weight and thickness, retrofitted into existing joineries, saving retrofitting cost, time and possibly avoiding the lengthy and costly Council consent. Finally, the government should provide funding in their long term budget that could be utilised during an economic crisis to help owners retrofit DGW in their homes to help stabilise the ‘boom and bust’ economic cycles in the New Zealand construction sector.

Overall, the study shows multifaceted difficulties associated with retrofitting DGW including high cost, relatively low knowledge, low return on investment, uncertainty on the length of time frame as well as accessing trades people. These issues have driven down the homeowners’ interest level in retrofitting DGW in their homes. Therefore, future research should be conducted to increase homeowners’ interest by establishing an accurate cost for retrofitting DGW, expanding on the literature to establish a strong knowledge platform that is easily accessible by the consumers. In addition, New Zealanders should learn and collaborate with a country such as Japan that has successfully implemented retrofitting their homes with DGW and enjoyed the gains from doing so.