Steel SIPs for Residential Building Construction: Lessons from Air Leakage and Thermography Analysis of Australian Houses

Abstract

Stick-frame residential construction is renowned for being leaky. Structural insulated panels (SIPs) theoretically resolve the issues with air and thermal leakage, but such construction systems are new to the Australian housing market. The purpose of this study was to determine the extent to which a steel-skinned SIP construction product could resolve air leakage and thermal performance challenges in five climate zones across Australia in 2015. All houses used the same steel SIPs as the main construction element (walls and roof). Airtightness and thermography tests were conducted in each house in winter to identify air and thermal leakage paths. The results show that even first-time users of this product can produce well-sealed homes, but there is a need to address thermal bridging (because of the steel componentry) and to consider the house as a whole system (not just walls and roof). The results of the study raise questions about thermography test procedures and airtightness regulations for naturally ventilated homes in warm-temperature climates. Addressing these issues will assist in the diffusion of innovative construction products and methods to enhance the energy efficiency of housing.