Articles | Exterior Systems

Thermal Effectiveness of Brick Veneer and Lightweight External Walls

Friday, 14 December 2018
By Dale Olsen

The Gypsum Board Manufacturers of Australasia has recently commissioned independent comparative research into the energy efficiency of conventional external walls and external walls with high thermal mass. For those moving towards smarter construction, thinking about cost effective building methods may be a greater differentiator when planning a project.

Prepared by Clarkson Consulting Services Pty Ltd, the wall systems analysis found “…. that when exposed to similar climatic conditions, the more commonly used construction systems (brick veneer and lightweight cladding – direct fixed or battened) provided very similar thermal performance when constructed with the same levels of BCA / BASIX compliant insulation and glazing.”

According to Bill Thompson, who sits on the GBMA sub-committee that managed the research project, the Clarkson Consulting review provides evidence that supports thermal credentials and benefits of lightweight construction using plasterboard.

“The report highlights the importance of cost effective construction, and identifies that the thermal performance of carefully considered lightweight construction can be similar to heavy elements."

“The report was not commissioned to identify one system as being better than another,” commented Thompson. "The  GBMA wanted to equip gypsum board manufacturers with information that could be shared with potential, new and existing customers when talking about smart construction." “What the review does qualify is the importance of insulation and glazing in smart residential construction. There is a stronger awareness of the importance of glazing, insulation and air leakage today than there was 20 years ago,” continued Thompson. “The performance of any sort of construction depends on the careful selection of lightweight material and air leakage minimisation. In addition to this, control of air leakage relies on product installation integrity.”

The GBMA aims to promote a more holistic approach to smart construction to ensure improved future building performance. The Building Code is reflective of the whole of house performance approach, with impending amendments to the code regarding glazing and air leakage due for release in 2019.

“The requirements around insulation, air leakage and thermal performance are very strong in Europe, primarily because of the aggressive climate and high energy costs,” stated Thompson. “Australia’s population is predominately on the east coast, where the climate is more benign and houses haven’t needed to be  constructed to cope with incredibly cold or hot temperatures. However, Australia is catching up because of its obligations to meet its 2030 climate change target, to align with the Paris Agreement.”

Overseen by Scott Clarkson, Principal Consultant of Clarkson Consulting Services Pty Ltd, the GBMA commissioned review concludes, “Whilst construction techniques such as cavity brick and reverse brick veneer, when properly insulated, may present significant annual savings in the operational costs of air conditioning, when balanced against the additional construction costs and potential delays in construction, more conventional construction systems (ie. lightweight cladding and brick veneer) can present more affordable and practical solutions to builders and homeowners.”

Press release from Gypsum Board Manufacturers of Australasia (GBMA), August 2018