Mud brick and rammed earth homes generally
have thick walls (approximately 300 mm) and high
thermal mass. When outside temperatures
fluctuate above and below comfort temperatures,
the high thermal mass of mud bricks considerably
reduces heat transfer, performing particularly well
In winter however, outside
temperatures are normally lower than comfort
temperatures and the low thermal resistance of
mud brick leads to poor winter performance as
heat is lost through the walls.
|Approximately six times as much heat passes
through a mud brick or rammed earth wall
compared to an insulated brick veneer wall. To
reduce heat losses in winter, it is advisable to
install external insulation to mud brick or rammed
earth walls. Avoid fixing insulation
to the internal face as this loses the thermal mass
benefits of earth walls.
If uninsulated mud brick or rammed earth is used,
limit winter heat losses by keeping non-north
windows as small as possible. All north windows
should be double glazed and the area of north
glazing should be at least 2530% of the floor
area, to help heat the building in winter. Ensure
that windows are shaded in summer.
Reverse brick veneer
Reverse brick veneer, as the name suggests, puts
the brickwork on the inside and timber framing on
the outside i.e. the reverse of traditional
construction. This form of construction enables a
timber-style home to achieve the same level of
thermal performance as a double-brick home.
By reversing the traditional construction type, the
high thermal mass of brickwork can be used to
advantage. Instead of being on the outside of the
insulation and hence isolated from the room, the
brick skin is within the insulation envelope.
Reverse brick veneer can be used in conjunction
with either a concrete slab floor or
a timber floor.
The upper storeys of homes have the potential to
overheat in summer as they are usually of
lightweight construction, with either brick veneer or
To prevent overheating, upper levels should
incorporate as much thermal mass as possible.
Thermal mass can be provided by a suspended
concrete slab floor, internal brick walls, the
continuation of ground-floor double-brick
construction, or any other technique that builds
concrete or masonry into the structure.
Windows to the east and west should be
avoided or minimised because of the tendency
to overheat. Limit the upper-storey window
area to the north at less than 10% of the upper
gross floor area. All windows should be
effectively shaded and positioned to allow