SA Affordable Housing September - October 2019 // ISSUE: 78 | Page 25

FEATURE
ENERGY EFFICIENCY
Building an energy-
efficient home
An energy-efficient home saves money by reducing energy use,
providing a higher level of comfort to its occupants and increasing
the resale value of the house. SANS standard 10400-XA requires
that 50% of energy in new developments since 2010 derives from
alternative energy sources.
By Eamonn Ryan
www.saaffordablehousing.co.za
R
ecent technological advancements in building
materials and construction techniques make the
process of building an energy-efficient home less
challenging. Most energy-efficient homes have several things
in common: a tightly sealed thermal envelope; controlled
ventilation; high-efficiency heating systems; energy-efficient
doors, windows, appliances, and home electronics; and high
indoor environmental quality.
All new affordable housing developments have to comply
with SANS standard 10400-XA – requiring that 50% of
energy in developments derives from alternative energy
sources – or they will not be signed off by inspectors. In
Montrose City Mega Development, profiled as SA Affordable
Housing’s [italics] September issue’s project, CEO Sam
Mhlaba explains that the development has attracted interest
from a solar energy provider, SolarReserve, although certain
approvals required remain, for instance from Nersa.
SolarReserve is a leading global developer of utility-scale
solar power projects, which include electricity generation by
solar thermal energy and photovoltaic panels. In addition,
SolarReserve has commercialised a proprietary advanced
solar thermal technology with integrated energy storage
that solves the intermittency issues experienced with other
renewable energy sources.
“The attraction of their system is the capability to store
energy in batteries, which means power is available at night
and in winter. The remaining question is the lifespan of the
batteries.” Apart from that, all geysers are solar-powered in
terms of the requirements of SANS standard 10400-XA.
Johan van den Berg, Business Development Manager at
Burgess Plumbing, says, “For the past nine years, developers
have had to comply with SANS standard 10400-XA. So, from
the moment of building the foundation, the developers
should simply adhere to South African national standards. In
order for any building to receive a certificate of occupancy,
every involved professional from the architect to the builder
needs to have complied.”
These are not necessarily high-tech solutions, he says, but
include the building materials. “It can, for instance, mean the
A heat pump reduces water heating costs by 60% to 70%.
use of high-quality roofing insulation such as polystyrene
ceiling boards (which is so thick it becomes insulation) or
roll-on glass wool insulation or blankets. In addition, all hot
water pipework is supposed to be insulated to a minimum
of class R1 ('R' stands for thermal resistance. The R value
depends on the type of material, its density and thickness).
In a ceiling, if you have the insulation resting on the ceiling
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