TIMBER & CLIMATE CHANGE
We’ve all heard about The Greenhouse Effect and Global Warmingâ€¦â€¦ but did you know using timber can counter this?
The burning of fossil fuels produces carbon dioxide and other greenhouse gas emissions.Â But research has shown that the growing timber forest absorbs carbon that is released into the atmosphere.
As the tree grows it absorbs carbon from the atmosphere and stores it in perpetuity.
One cubic metre of growing forest contains 200 kilos of carbon.
It is estimated that trees absorb 25% of fossil fuels emissions of CoÂ². Using one cubic metre of wood results in 0.8 tonnes of CoÂ² sequestration.
So the extraordinary product we are associated with has a two-fold benefit:Â The forests where it originates function as carbon sinks, then once absorbed the products produced from
the raw material by the wood processing industry act as carbon stores after conversion.
What other building material product â€“ Plastic â€“ Steel â€“ Concrete can emulate this?
On average, wood used as a substitute for concrete or steel will save a further 1.1 tonnes of CO2 creating a total saving of 2 tonnes a cubic metre.
In 1990 the forests were calculated to be absorbing nearly half the total carbon emissions produced by burning fossil fuels.Â Since then the area of forest has increased.
This is the only building material whose subsequent use in products and buildings stores and absorbs the carbon and isÂ conducive to the concepts of The Kyoto protocol.
Source:Â The Finnish Timber Council 2008.
WOOD CAN BE RE-CYCLED
Wood is one of the only materials, which can be listed as Eco-Effective.
It is organic â€“ recyclable and 100% biodegradable.
All of the tree can be utilised.
When a tree is harvested, the branches and in some cases the needles remain on the forest floor to rot down and re-fertilise the ground.
The by products from the conversion of the tree, bark and some branches are converted into bio energy fuels or garden products.
The sawmilling industry targets 100% yield from the log, as itâ€™s absolute.
The by products which cannot be used as solid timber also have 100% utilisation â€“ the chippings/sawdust is further processed into particleboards for example.
Or it can be completely utilised into pellets for Bio Fuel heating plants.
Or it can be wholly converted into pulp and paper.
When wood products are removed from service they can be used again either in their current form without modification or further processed and converted into new items (which saves processing new material) with all the subsequent benefits.
As an organic material, it will biodegrade easily.Â What other material will do the same?Â A growing trend is to re-process waste wood into alternative energy thus reducing the demand for non-renewable fossil fuels such as oil, gas and coal.
LIFE CYCLE ASSESSMENT AND ENERGY EFFICIENCY
Impartial and unbiased scientific research demonstrates that when Timber is environmentally evaluated across its entire life span from extraction to processing and through to total life usage and final disposal, it can compare favourably with any alternative material.
As trees grow they naturally absorb CO2 from the atmosphere. A typical tree absorbs 0.9 tonnes of carbon for every cubic metre of growth.Â Trees are essential in the fight against climate change.
A cubic metre of wood contains roughly 0.8 tonnes of CO2
The production of sawn goods consumes considerably less energy than for other building materials.Â Concrete requires double the amount of energy whereas Brick production requires Four Fold the amount.Â Even though further wood processing, such as Chipboard manufacture, requires many more times the energy than is used for sawn timber most of this is renewable wood energy generated at the mill.Â On top of this Aluminium is the most energy intensive of all materials.Â Source: Puu info 2008.
When comparing like for like construction.Â The building of a similar sized warehouse with wooden walls consumes 1500GJ of energy compared with the same building in steel walled elements consuming 3000GJ.Â Source: The Year of Wood/TRADA.
Achieving low-energy housing is more cost-effective using timber-frame construction than conventional brick and block. Well constructed timber framed dwellings can comfortably deliver significantly better levels of air permeability than the required limit under building regulation requirements, by using 140mm stud solutions and full depth insulation, can achieve 0.27W/mK
When comparing like for like items such as windows:Â To produce a standard size wooden sash window requires 64kwh of primary energy whereas aluminium requires more than ten times this figure.Â Source: Katalyse GmBH.
Wood windows which are double glazed and painted in the factory have 30 year durability warranties, paint guarantees of up to 10 years and can provide improved energy ratings, beyond Part L requirements depending on the type of glass selected.Â Wood windows are easier to triple glaze too.
The LCA-House model for comparing the construction of exterior walls conducted by The Technical Research Centre in Finland concludes: The largest amount of renewable energy and least amount of fossil fuel energy used in wall construction is one built from wood and it causes the least amount of greenhouse gases and sulphurous emissions.Â Walls produced from concrete consumed the largest amounts of non renewable resources and produced the largest emission amounts of Carbon Dioxide per square metre of wall.Â Source: LCA-House model Sirje Vares VT Building & Transport.
The Canadian Institute of Sustainable materials, Athena, has used the Life Cycle Assessment (LCA) method to evaluate buildings with a frame of wood, steel and concrete.Â When compared with a range of environmental criteria, the wood frame building was the clear winner.Â N.B. The research was based on conditions in North America and the size of houses and levels of energy consumption were the same for all buildings, only the frame and wall materials differed.