Why do we choose wood?
Wood is an extraordinary material. It is beautiful, light and strong to build with, warm and welcoming to live with. Naturally renewable, it grows in ever-increasing abundance in Europe.
Triple bottom line
While the European timber industry recognizes the importance of the sustainable “triple bottom line”, where long term economic development must be balanced against the need to respect the environment and the interests of society as a whole, setting universal targets is impossible, given its diversified and fragmented structure across Europe.
Environmental issue and energy crisis are two critical problems China and the world is facing in the urbanization process. Due to its innate characters, using wood as much as possible is one of the best solutions to tackle the climate change and reduce the resource consumption.
Carbon sink and climate
Wood offers a simple way to reduce the CO2 emissions that are the main cause of Climate Change, through the carbon sink effect of the forests; the carbon storage effect of wood products; and the substitution for carbon-intensive materials.
- On average, trees absorb 1t of CO2 and release almost 727kg O2 for every cubic metre’s growth because of the photosynthesis.
- Wood is “carbon negative” because it stores most of the CO2 absorbed by the harvested trees as carbon, and sustainable forest management requires that the harvested wood is replaced by more trees, adding to the carbon sink of the forest.
- Wood products use less energy (and CO2) to manufacture than other products.
- Wood buildings also reduce CO2 emissions as a result of their energy-efficiency.
- By using wood, the use of non-renewable, fossil fuel-intensive materials (such as concrete and steel) can be reduced. Therefore, substituting wood for other materials can reduce substantial reductions of CO2 emissions and stimulate the expansion of forests.
- Forests need metabolism to maintain and increase the ability of storing CO2. Because young, active trees absorb yet more CO2 than the mature trees, which should be harvested and replaced sustainably.
- Europe’s forests are growing by 0.8 million ha a year. In the last 20 years they have grown by 16 million ha – an area roughly twice the size of Ireland. The wood used in construction in Europe comes from sustainably managed forests, as only about 2/3 of Europe’s forests’ annual growth is harvested.
- Widely using wood and prosperous markets are important drives to forest growth under regulations and management.
There is no waste of the raw material when producing wood products, as every part of wood is used, from bark to sawdust. Material wastage is minimized due to accurate, pre-fabricated elements in factories before assembly. Leftover and low strength material can be used for engineered wood products.
Most of the wood products without severe damage and corrosion can be reused and repaired several times, significantly saving raw material.
Products and elements not suitable for reuse can be collected and reprocessed for recycling to extend their CO2 benefit and life span. Little environmental impact is generated.
Wood products and by-products at the end of their life can be used as a biomass fuel by recovering the energy in the wood, substituting for fossil fuels.
Energy efficiency is “one of the most cost-effective ways to enhance security of energy supply and to reduce emissions of greenhouse gases and other pollutants”. Wood as a construction material can provide a solution to improving the energy performance of buildings cost-effectively; numerous international scientific studies have found that wood-framed buildings involve lower GHG emissions than their steel and concrete-framed counterparts (26% and 31% respectively). Furthermore, in the residential sector, steel and concrete-framed homes consumed 17% and 16% more embodied energy and released 14% and 23% more air pollutants than a wood-framed home.
- Wood construction consumes minimal energy.
Wood is light and easy to put together on site, requiring little or no use of heavy-duty equipment. Foundations are minimized. Transport requires less energy. All these consume less energy than other materials and structural types.
- Wood is a good thermal insulator.
It is 400 times better at resisting thermal conductivity than steel, and 10 times better than concrete or bricks. They outperform Chinese energy codes and reduce the cost for meeting the codes.
The growth and increasing density of our cities comes at a price; a price paid by the environment, as well as by developers. Today’s wood industry provides innovative ways of reducing that cost. Building with wood is faster, cleaner, lighter, more flexible – and more environmentally-friendly. Wood’s high strength and low weight, its suitability for off-site production, its low carbon impact, natural renewability, wide availability and cost-competitiveness make it the building material of the 21st century.
Determining the true costs of a building material requires evaluating the product over its life cycle and taking into account its environmental as well as monetary costs. When considered over its lifetime – from harvest of raw materials through manufacturing, transportation, installation, use, maintenance and end-of-life options – wood performs better than concrete and steel in terms of embodied energy, pollution to air and water, and overall carbon footprint.
Wood frame construction has superior seismic performance, even in the most severe earthquakes.
- Wood frame buildings save lives and reduce the cost of reconstruction because they are strong, light and flexible.
- Plenty of surveys, tests and real cases demonstrate that wood frame buildings are safer than concrete and masonry buildings in areas with a high risk of earthquakes.
With good design and correct detailing, structural wood needs no chemical treatment to achieve a long life. Wood is resistant to heat, frost, corrosion and pollution; the only factor that needs to be controlled is moisture.
Timber construction materials are kiln-dried to specified moisture levels, removing the need for chemical wood treatment in interior use. Externally, design elements, such as large roof overhangs and sufficient distance between timber and ground are important. Timber facades are non-load bearing and therefore do not require treatment. However, extended life spans can be achieved by using heat treated timber, special timber qualities, treatments or decorative finishes.
Unlike many other materials, timber behaves predictably in fire, forming a charred surface which provides protection for the inner structure, so that timber elements can remain intact and fully load-bearing during a fire.
Fire safety is assured by fire-rated, finished assemblies and code-compliancy. The fire-retardant detailing of modern timber construction prevents cavity fires and the spread of combustion gases.