WOOD WISE
Timber as the dominant
construction material
for building:
Part 2.
By Stellenbosch University (Presented at the Wood Conference 2020)
Can timber resources compete on a 100% timber-build housing market share?
Construction contributes to around one third of global
carbon emissions, so the way in which buildings are built
is a really important consideration.
As a recap into our research into this subject: We posed three basic
questions we wanted to answer:
• How does wood compare to competitive building materials in
terms of environmental sustainability (in a South African
context)?
• What will the environmental impact be if we become a ‘wood
building’ country?
• Can we sustain a dominant residential wood building sector
with local forest resources and services?
Part 2 of this study looks at potential resources for wood housing in
South Africa, and the South African transport impact on Global
Warming Potential (GWP). Please see Part 1 published in the
previous issue of Timber iQ.
SUSTAINABILITY ASPECTS WITH LOCAL
MATERIALS
Considering our timber resources and by-products of the industry
our research looked at some of the most obvious sources of
materials (see Diagram 5). One being the export of significant
amounts of wood chips to Asia for pulp and paper factories.
housing. We can determine how much wood chips would be
needed to build a typical timber-framed house and the result is
47 531 houses (of an average size of 114m 2 ). Considering our
estimated housing requirement of 54 000, this resource alone would
be a sustainable source.*
The second resource that is highly feasible is afforestation, such as
in the Eastern Cape where the Government has identified 140 000
hectares of land for this purpose. Once this solution is in full
production it can sustain approximately 37 000 houses per year.
Within as few as eight years a project such as this could already
start producing the timber required. Other studies show that
dryland afforestation in the Western Cape is another potential
source. As you can see, we have more than enough resources to
compete on a 100% timber-build housing market share, which for
us was quite a surprise. Essentially there is no excuse not to build
with wood.
IMPORTING AND TRANSPORTATION –
IMPORTANT FACTORS
Different transport modes have very different environmental
impacts. If you look at truck transportation, this method has a
9-times higher GWP impact per tonne moved than container
shipping, and then dry bulk shipping is approximately half of that
(see Diagram 6).
Diagram 5: Potential resources for
wood housing in South Africa.
Diagram 6: SA transport impact on GWP
Wood chips are a very low-value product currently, so this resource
has the potential to be upscaled to a high value product, like
The bottom line with transportation is your shipping distances are
constant and so you can’t do a lot around that, however you
www.timberiq.co.za // OCTOBER / NOVEMBER 2020 23