SA Affordable Housing January / February 2017 // Issue: 62 | Page 15

COVER STORY

University of Pretoria
releases energy usage study
of walling in South Africa
The University of Pretoria has released results of its Thermal
Performance Study, which assessed operational energy use of
structures built with six different walling materials.

Photography courtesy of Berts Bricks.

W

hen selecting building materials, developers and
architects of green buildings take into account the
embodied energy of their raw materials. While
this is an excellent start, in reality energy use over the life
of the building dwarfs energy used during production.
Operational energy use is an expensive, long-term cost for
the property owner and a drain on South Africa’s limited
resources.

Annual Operational Energy is the sum of all
heating, cooling and ventilation electricity costs
accumulated over all four seasons in one year.
This research is of particular relevance for affordable
housing, as the residents do not have the money for high
electricity bills. Therefore ethical housing developers
should look beyond cost-cutting during construction, to
take into account the long term expense of operation and
maintenance.

METHODOLOGY OF THE STUDY
The size and use of a building influences its thermal
performance. The design models applied in this study were
used in prior research by the Council for Scientific and
Industrial Research (CSIR) and the Department of Mineral
and Energy Affairs. Best-practice construction methods
were assumed, as required by SANS 10400 Part XA: Energy
usage in Building and SANS204: Energy efficiency in
building.
Three building types were analysed:
• A large 2 000m2 commercial building that is unoccupied
at night and on weekends.
• A middle-income residential home of 130m2.
• A low-income home of 40m2 (with heating fuelled by
coal or paraffin).
Variables such as floor, roof, windows, doors and
occupancy patterns were kept constant.

AFFORDABLE
SA HOUSING

JANUARY - FEBRUARY 2017

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