MAKE YOUR LIFE GREENER,
CHOOSE WOOD PRODUCTS

There is a very simple way to respect the environment and to preserve it for future generations: simply by choosing wood products one reduces greenhouse gas concentrations in the atmosphere which has great benefits for the environment.
It is imperative that governments and citizens make the greatest efforts to reduce greenhouse gas emissions. Increases in CO2 emissions can be offset to an extent by their accumulation in carbon sinks such as forests and other plant biomass. It has also been recognised that wooden materials (harvested wood products) are an important pool of carbon and that they constitute a carbon sink (see e.g. Brown 1998, IPCC 2006, IPCC 2007). Choosing wood products reduces atmospheric levels of greenhouse gases in two particular ways:
• It is well known that trees clean the air by absorbing carbon dioxide (CO2). But not everybody knows that wood products continue to store much of this carbon, which is kept out of the atmosphere for the lifetime of the product – even longer if the wood is re-used and recycled. Basically, 50% of the dry weight of wood is carbon.
• Manufacturing processes associated with wood products require less (fossil fuel-based) energy and are responsible for far less greenhouse gas emissions than the manufacture of other major building materials. According to research 'substituting wood products for more greenhouse gas (GHG)-intensive building products in cladding, wall, roof and floor framing could reduce the GHG emissions of a typical house by up to 18 tonnes over its life'.

Until the 17th session of the Conference of the Parties to the UN Framework Convention on Climate Change (COP17) held in Durban, South Africa, in December 2011, the role of wood as a carbon store was not officially recognised. The regulatory framework that resulted from the Kyoto Protocol made it possible to place a value only on emission reductions linked to the utilisation of wood as a renewable energy source. In the Kyoto Protocol – United Nations 1998 – carbon sequestration of wood products is not included as a possible tool for countries to use in meeting their CO2 emission targets (principle of the default method that assumes instantaneous release of all carbon at the time of harvesting).
However, during COP17, the accounting for forest management and harvested wood products was made mandatory for developed countries. Finally it was clearly recognised that the default assumption was ignoring the reality that carbon is stored for decades in wood products and eliminating a significant portion of the wood product life cycle. Furthermore, it gravely underestimated the role of wood products in reducing GHGs and as part of the solution to mitigating climate change.
Following the Durban decision, the European Commission had the intention of closing the current gap in greenhouse gas accounting in its climate policy and proposed, in March 2012, a harmonisation of the rules to account for forests and agricultural soil emissions across the EU as a first step to incorporating these sectors into the EU's reduction efforts. Through the Durban Decision and the Proposal for a European Decision, Member States will be able to provide incentives to increase sequestration of CO2 either by increasing the carbon stock in wood products or by using wood as a substitute for more energy-intensive materials.
The proposed European Decision establishes accounting for harvested wood products; this will provide an enabling framework for more targeted policies at national and at European level, officially recognising that carbon can be stored for a very long time in harvested wood products (houses, bridges, furniture, paper products). National wood-product inventories would need to be carried out regularly, while annual consumption figures and decay estimates could be used to complement the inventory work. Moreover a reliable monitoring system will help Member States to support and introduce 'wood-first' policies aimed at increasing the pool of harvested wood products. The substitution of more energy-intensive, nonrenewable materials by wood results in substantially lower carbon emissions. Emissions differences are due to the fact that a large portion of the energy used in producing wood products is typically produced from wood residues. Following the adoption of the European Commission Proposal for a Decision, ad hoc measures should be taken on a national level to effectively bring about recognition of the energy-efficiency-related carbon benefits of wood as compared with other materials.

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Building materials and constructions - Wood is part of the solution

Using renewable materials with low-carbon footprints and improvements of energy performance of buildings to reduce emissions provides low-cost and short-term opportunities. As explained before, the main opportunities are the storage of carbon in wood and wood products, the potential offered by the substitution of other (energy or carbon-intensive) materials and the efficient eco-cycle of wood products.

Managed forests are more efficient carbon sinks than forests left to grow unmanaged. The CO2 of the trees harvested from a managed forest continues to be stored throughout the life of the resulting wood product. The wood products' pool may grow either by expanding the usage of wood or by extending the average life span of the products.
The manufacturing of materials for a wooden building uses 28% less primary energy and emits 45% less carbon than the manufacturing of materials for a similar concrete building. The cost of energy used for material processing is lower for the wood-frame building, and the relative energy cost becomes lower for the wood building as climate-related externalities are more fully reflected in the production cost. (See Roger Sathre, Leif Gustavsson. 'Using wood products to mitigate climate change: External costs and structural change' in Applied Energy 86, 2009, 251–257.)
The European wood industries already provide workable solutions to limit the emission of greenhouse gases, solutions which contribute to achieving the ambitious policy goals of the EU. Wood and wood-based products are, therefore, a first choice for future EU society. As a flexible and modern engineering material, combining innovative, engineered wood products with new building techniques, wood offers ample opportunities for:
• New housing (residential and non-residential, single- or multi-family housing), prefabricated modules
• Extensions to existing buildings
• Renovation
It is cost efficient to build with wood. The cost of the wood frame is about 30-35 % lower than that of a concrete frame. The total cost is about 10-15 % lower for wood buildings. Using prefabricated modules the total cost is 20-25 % lower. The time savings can be up to 80% and during the building phase CO2 emissions can be reduced up to 85%. Wood offers great potential for changing and modernising existing, older buildings which are often constructed from concrete. It is primarily a matter of extensions to roofs and storeys. This offers a great potential for big cities to increase the number of dwellings on existing ground.
The simplest method is to fit an old building with a new roof designed in such a way that a number of flats can be built into the attic. As timber structures are light, there are also opportunities for additional storeys, e.g. through the use of prefabricated components.
Wood's naturally good thermal insulation properties make it the material of choice in both cold and hot climates. There are thus significant CO2 savings to be made by using timber in the construction of housing and other buildings, both in terms of embodied energy and in-use energy efficiency. At the end of their service life, the wood products can in most cases be recycled, thus extending the carbon storage effect, and/or be used as a carbon-neutral fuel, substituting for fossil fuel sources.

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Building techniques

Several common techniques are available for constructing buildings with supporting frameworks made of wood. One way is to use structural wood members to form a frame which is covered with structural wood panels. Foundations are generally concrete. This simple building technology is often used in the construction of single-family houses but also in the construction of multi-storey buildings. Another technique is to use solid timber for the supporting framework. Cross-laminated boards are glued together and used to build walls and joists. The walls may need to be insulated to give the building a high level of energy efficiency. The technique is well suited to the construction of multi-storey buildings. Yet another technique is the system of columns and beams. In this case cross-laminated timber in different forms is used to a large extent for the load-bearing construction. All the framework systems mentioned satisfy modern criteria for fire safety, noise pollution and energy efficiency. Special consideration must be given to these functional criteria in the case of multi-storey buildings. Well tested technical solutions are now widely available.