The ability of building materials to store heat is
referred to as thermal mass. Building materials that have a high
thermal mass, such as internal bricks and masonry and a concrete
slab with hard floor coverings, can store large amounts of heat
without a large temperature change.
In places where the difference between day and night temperatures
is eight degrees or more, there are benefits in using high levels
of thermal mass inside north-living zones to stabilise internal
temperatures in both summer and winter. The correct use of thermal
mass inside a house can significantly improve both thermal comfort
and energy efficiency.