Timber iQ February - March 2019 // Issue: 42 | Page 52

WOOD WISE
Trees help reduce climate change by absorbing CO 2 and storing it.
Continued from page 48
‘Construction design with a focus on energy efficiency
through lightweight timber can greatly contribute to
maximising comfort and minimising non-renewable energy
use. […] The natural thermal properties of timber also
maximise the energy efficiency of insulation material as
wood will not become cold or dissipate heat, therefore
requiring less energy to maintain warmth throughout
a building.’
While the higher the thermal resistance of a material in
construction, the better; the lower its thermal conductivity,
the better it will insulate. According to the Peter Müller
website, ‘Thermal bridges are areas where, for example,
heat is lost through a switch in materials than in
neighbouring structural elements. Thanks to the low
thermal conductivity of wood, the thermal bridge effect of
wooden structural elements is very slight.’
The walls, floors and roof of a timber home have the
capacity to take on almost any type of bulk insulation,
which means that the structure’s ambient temperature will
behave more moderately regardless of seasonal changes
and require less energy for heating and cooling, provided it
is designed in line with energy efficiency regulations.
Building envelope sealing is also a significant potential
contributor to a structure’s thermal performance with the
addition of plywood or oriented strand board (OSB) and
sheathing overlaid with the cladding of choice, all adding
thermal value to the wall structure and limiting thermal
transmittance. One can implement all kinds of energy
50 FEBRUARY / MARCH 2019 //
efficiency measures, but if the building envelope is not
properly sealed, the thermal performance of the structure
will drop significantly, negating all the energy efficiency
measures implemented in the first place.
CHAMPIONING WOOD WORLDWIDE
The construction sector globally has a duty to make more
responsible, better informed decisions about how it plans
and executes its work for a more sustainable future; there is
no more room, excuse, or time for ignorance and self-
indulgence. While timber alone may not be a silver bullet
for our carbon footprint woes, it does represent nature’s
commitment to the solution.
With well-considered planning, sourcing of responsibly
grown timber, adherence to legislation governing energy
efficiency and usage, timber as a construction material is
poised to be at the forefront of energy efficient and
sustainable design and construction in South Africa.
There is no denying that all building materials have
something to offer the construction sector and its end users,
but it is now a crucial time for timber to fully occupy – and
be appreciated for – its role as a viable construction
material with high potential for legitimately sustainable
construction. Nature has come to the table; it is time for us
to take our place there as well.
Werner Slabbert is the director of Rustic Homes, timber
home building pioneers since the 1980s.
www.timberiq.co.za