Due to changes to the BCA and the new BASIX
requirements for housing there is a rethink in regards to
There are many mis - conceptions out there in
regards to the thermal efficiency of various building materials.
Cavity brick walls have high thermal mass,
but without insulation are usually too cold in winter, and often too
hot in summer if exposed to prolonged heat wave conditions.
If the cavity is insulated, the internal thermal
mass (i.e. the internal brick skin) is protected from external
temperature changes, and becomes highly effective at regulating
temperatures within the home.
Brick Veneer (BV) walls have the brick skin
on the outside, which is not the ideal location for thermal mass.
The bricks heat up in summer and radiate heat late into the evening,
while in winter they stay cold and absorb heat from the house.
Insulation is essential to protect the occupants from external
temperature extremes that are exacerbated by the external brick
Reverse Brick Veneer (RBV) is much more
thermally efficient because the thermal mass is on the inside,
however good insulation is still important.
A lighter skin is used on the outside such as
fibre cement, timber or steel. This lighter skin does not retain the
heat in summer and does not absorb the cold temperature in winter.
The internal skin of thermal mass, ie brick,
retains the ambient temperature from the inside of the house.
Timber framed walls are low mass
construction, and rely entirely upon insulation to maintain thermal
comfort. If the insulation has been installed and calculated
properly these homes can be very thermally efficient.
Many traditional homes especially in Queensland,
are built in this way with excellent results.
This shows that typical building construction
methods used in Sydney will be changing to these new Government