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design
mag
Bricks, energy and the
Australian home
The energy used in the daily operation of an
Australian home when averaged over its life
is estimated to be over 90 percent of its
combined embodied and operational
energy.With the largest proportion of this
energy being used for heating and cooling
(38 percent), there is an emphasis on
targeting thermal comfort in homes as a
way to reduce energy use.An energy-
efficient home provides a high degree of
thermal comfort without over-reliance on
artificial heating or cooling, while offering
adequate natural light and ventilation.
The ability of the earth to capture and hold
heat has been harnessed by mankind since
the dawn of civilisation.The process of firing
clay provides water resistance, stability and
strength, although the energy required to
achieve this is significant. By weight, brick
manufacture requires a relatively low
amount of energy, though the weight of
brickwork in domestic wall construction is
comparatively high. However, the energy
used in their manufacture – embodied
energy – is small when considered over the
life-cycle of a building.
With almost 90 percent of new homes in
Australia using brick construction, it is
important that designers and other decision
makers are aware of how to take full
advantage of the energy-saving potential
that clay brick construction offers.
Where interiors are exposed to enough
thermal mass, the warmth of the day can be
captured and held to increase comfort on
cool evenings, and the cool of the night can
be captured to improve comfort on hot
days.The higher the variation between day
and night temperatures – the diurnal
variance – the greater the potential for
brickwork to moderate interior house
temperatures.
New research highlights the benefits
of using bricks
It has long been known that the thermal mass of brick is high due to
density.This research quantifies the ability bricks have to absorb, slow the
transfer of, and re-radiate heat in a way that offers more occupant
comfort than just considering their measured resistance to heat transfer
(R-value).
Working with Think Brick Australia since 2002 to quantify thermal
performance,The University of Newcastle’s Priority Research Centre for
Energy built and monitored four identically-sized (six metres square) test
buildings that mimicked standard domestic construction. Each building
had a concrete slab-on-ground floor, although wall constructions varied:
• Cavity brickwork
• Brick veneer
• Reverse brick veneer
• Lightweight (timber-framed) construction
‘A Study of the Thermal Performance of
Australian Housing’, the first stage report
of an eight year research program, was
published in June 2011 by Think Brick
Australia’s research partners at The
University of Newcastle.The research
explores the thermal advantages of clay
brick in domestic construction and
shows that brick construction can
improve thermal comfort and therefore
reduce energy usage.To harness this
potential, bricks need to be
acknowledged not just for their insulative
properties but more importantly for their
thermal capacitance (thermal mass).
The Austral Bricks-Ausbuild 8
Star Display House in Victoria
Point, Queensland
demonstrates that comfort,
sustainability, affordability and
contemporary style can be
affordable and attractive.The
thermal mass inherent in clay
bricks is an essential
component of a passive
design.