FEATURES
MINIMAL CARBON FOOTPRINT
Wood can go through material recovery and be used in the
manufacture of fibreboard.
use of other construction materials from non-renewable
sources, which in turn will reduce carbon emissions,
which is called the substitution effect.
• Wood is a flexible material, and wooden buildings are
easy to refit and extend, so they can enjoy a long useful
life.
• Building regulations on low energy use are easily
achieved with wood construction systems. In addition,
wood has good heat insulation properties, which reduces
the need for extra insulation.
• Wood can be reused; flooring and windows, for example,
can be reclaimed and used in another building. This
prolongs the time that the carbon dioxide remains stored.
Wood can also go through material recovery and be used
in the manufacture of fibreboard, for example.
End-of-life phase
• At the end of their service life, wood products are used as
biofuel and replace fossil fuels, which is also an important
benefit for the environment.
When end-of-life wood products are used as biofuel or
composted, the stored carbon dioxide is released. But in
contrast to carbon emissions from fossil fuels, the
incineration of wood does not add new quantities of carbon
dioxide to the atmosphere. The released carbon dioxide is
instead absorbed by newly planted and growing trees
through photosynthesis. The circle is therefore closed, and a
new eco-cycle can begin.
www.timberiq.co.za
So far, the main focus of the debate on buildings’
environmental impact has been on the usage phase, which is
the time from completion of the building until it is
demolished. But to gain a full picture of energy
consumption, we should also look at the construction phase.
Because, even if we build zero energy buildings, the fact
remains that the manufacture of the construction materials
and the actual construction phase have a negative impact on
our climate. It is therefore important to use construction
materials and construction methods that have a minimal
carbon footprint.
Modern construction methods that use wood make it
possible to achieve a minimal impact on the climate from
buildings that also meet today’s demands for reduced
energy consumption. Wood is nature’s own solution to the
climate issue.
According to research conducted by Mid Sweden
University, a four-storey building in wood provides net
storage of 150t of carbon dioxide because the wood stores
the carbon dioxide absorbed by the growing trees. No other
large-scale construction material has this capacity. The
analysis takes account of the energy consumed in
manufacturing the wood, in transport and in the production
of the building.
Part of the solution to the climate issue is growing right
here. Wood is both renewable and recyclable and has a
remarkable capacity to store carbon dioxide.
A RENEWABLE MATERIAL
The construction sector in Sweden emits carbon dioxide at
an annual rate of 10 million tonnes, which is equal to all car
traffic combined each year. Many commentators believe that
a need exists to review the way in which building is done
and the impact construction has on the climate. We need to
see change.
Wood will be a vital resource in this change, with the
material not yet reaching its full potential in the
construction sector. We will be able to build more large
buildings in wood in years to come.
The Kyoto Protocol’s international commitments to cut
emissions of carbon dioxide are likely to lead to an
increased use of timber in buildings. Many countries have
launched national wood construction programmes as part of
their strategy to replace more energy-intensive construction
materials with wood. Interest and investment in wood
construction techniques is growing all over the world – even
in countries with little in the way of domestic forest raw
material.
The key benefits of building with timber can be
summarised in the following five points, the first four of
which relate directly to the material and the fifth to the
construction technique:
• Low energy consumption when extracting wood products
for construction purposes from the forest, plus a large
quantity of carbon neutral bioenergy stored in wood
products. Carbon neutral means, in principle, that if the
// JUNE / JULY 2019 39