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By Cathy Inglis*

Using bricks to build your house can be a much smarter move in the long term than installing an air-conditioner

There is no doubt global warming is the big issue facing this and future generations. Australians are demanding urgent action to reduce greenhouse gases. But much can be done with the building materials and design of domestic architecture.

An Australian life cycle analysis
A life cycle study of a typical project home has been conducted by the Centre for Sustainable Technology at the University of Newcastle. The computer modelling was based on a small project home in the Sydney climate zone. The study encompassed all stages of the life of the house.
The researchers found that over the lifecycle “utilisation energy had the greatest environmental impact” and was found to account for ‘more than 90 per cent of energy consumption and greenhouse gas emissions.’ Put simply – everyday family living has by far the greatest environmental impact.
In particular, the energy consumed and greenhouse gases emitted over the lifetime of an average house is under the spotlight. This can be examined by a process called life-cycle analysis (LCA).

LCA takes a long-term view on energy consumption. It examines the total environmental impact of a building material or product through every step of its life – from obtaining raw materials, and manufacturing the building materials, through to its use in the home, and ultimate disposal or recycling.

All manufactured products have an embodied energy component, that is, the amount of energy it takes to actually make them. When it comes to materials such as bricks for example, the energy embodied in them is minor by comparison to that consumed in everyday living.

The energy saved, by reducing the use of an air conditioner by just one third over ten years, will offset the entire energy embodied in the bricks of a typical brick veneer house.

Instituting simple household changes can result in savings in greenhouse gas emissions that far exceed greenhouse gas emissions generated as result of the manufacture of a house load of bricks.

For example, a brick veneer house built on passive design principles will reduce or even eliminate the use of air conditioning.
Extra power generation plants are also needed to cope with the peak load on summers hottest days, all because of the dramatic increase in air conditioning use. Reducing this need is easily achievable by using passive design and investing in the embodied energy in thermal mass for long term energy savings.

Greenhouse gas emissions (GHGE) associated with the embodied energy of the bricks in a typical brick veneer house of 8,000 bricks amount to 5.1 tonnes. For a cavity brick or full brick home of 22,000 bricks the greenhouse gas emissions (GHGE) would be 14.1 tonnes.
However, household energy consumption of a typical Australian household amounts to an incredible 400 tonnes. It certainly puts the 5.1 tonnes from the embodied energy of clay bricks into perspective! 

Consider thermal mass
Consideration should be given to building materials that will enable the heating and cooling energy to be reduced. It is especially important to choose materials with thermal mass that have the potential to reduce the energy consumed over the life of the building.
The thermal mass inherent in clay bricks is an essential component of passive design; a proven technique that can reduce the energy used to artificially heat and cool a home to dramatically reduce greenhouse gas emissions.

So, the embodied energy of clay bricks is a one-off investment that has the potential to provide substantial savings in energy use and greenhouse gas emissions now and into the future. The durability, low maintenance, long life and recyclability of clay bricks also reduces the long-term environmental impact of a home.

Austral Bricks has produced a background paper - Taking the Long View: Embodied Energy & Life Cycle Analysis which is available by ringing (02) 9830 7700 or by visiting www.australbricks.com.au

Austral Bricks holds NCSI certification to the ISO 9001 Quality Standard, and NATA testing accreditation.

-Cathy Inglis is the Group Technical and Engineering Manager at Austral Bricks/Bristile Roofing/Eureka Tiles/Brickworks Ltd. She holds a Bachelor of Science (Materials Science) from the University of Technology, and a Master of Science, University of Technology. She can be contacted on (02) 9830 7700 or 0414 447 571. Email cathy.inglis@australbricks.com.au