Wood has long held a natural place in our homes and gardens, in the form of flooring, mouldings, cladding, decking, fencing and so on.
Wood is also a popular and proven construction material. Today, around 90 percent of single-family homes are built with wood. When it comes to multi-storey buildings, wood is a material on the rise in modern construction, with almost 20 percent of high-rise blocks having a wooden structural frame. Wood is also used in other structures, taking up the load in halls (40 percent of new builds) and bridges (20 percent of new builds).
However, there is a shortage of wood despite the fact that the world has more than enough forest soil to provide wood for the earth's peoples and that with proper forest management and utilisation enough wood could be produced to supply all existing needs.
According to FAO corporate document repository, the present lumber and housing shortage is serious. Millions of buildings are in need of repairs; millions of new buildings are needed to restore housing standards to pre-war levels.
World supplies of lumber are already insufficient to meet current demands, and when reconstruction programs attain full momentum, the deficit will be even greater.
In addition, there is a long-standing wood deficit, of which the present critical shortage of structural wood is only a part and which, in many parts of the world, has had pernicious affect for decades. This shortage is all the more serious because of rising demands for wood for pulp and for a growing wood chemical industry.
Therefore, using modern and advanced methods to manage the forest and make it to be more sustainable is very important.
Sustainable Forest Management
Sustainable forest management is not just about preserving the quantity of forests for future generations, it is also about respecting the biological diversity of the forests, the ecology of the species living within it.
Sustainable forest management will, in other words, maintain the balance between economic wood production and respecting wildlife and vegetation, outdoor recreation, employment and local interests.
About 100 years ago, Sweden introduced forestry legislation that limited the amount of timber that could be harvested, and imposed an obligation on woodlot owners to carry out regeneration after felling, contributing to sustainable management.
Sustainable forestry ensures an increase in the stock of growing wood—for each tree that is cut down at least two new ones are planted. Since then forest resources have doubled. Forest policy places equal emphasis on environment and wood production.
Modern Swedish Forest Management
Swedish forest management is moving towards methods that enhance natural processes and produce authentic forest structures which are environmentally appropriate, socially beneficial and economically valuable.
Site-specific forestry takes into consideration the varying conditions of the individual site. This ensures greater variety and minimises negative effects on animal and plant life. Major resources are being committed to conservation, education and development.
The forest worker of today is a skilled and environmentally conscious professional. Protected zones are left untouched on the banks of waterways, old trees are saved and dead wood is left in the forest.
One consequence of this awareness is that large scale clear-cutting is almost entirely abandoned today. It is estimated that the large industrial forest enterprises now leave some 10% of the potential harvest standing for ecological reasons.
Sweden enjoys a high level of forest protection. About four million hectares of productive forest land are formally protected as national parks, nature reserve habitat protection areas and nature conservation agreements.
The Swedish forest industry knows that its future is linked to the protection and expansion of its forests. This, in combination with strong, effective laws, ensures more trees are planted than harvested.
Ever since 1903, the mandatory requirement for regeneration after felling has had a central role in Swedish legislation. Annually 170,000 hectares are planted with some 370 million seedlings.
Natural regeneration occurs in about 50,000 hectares. The Swedish Forest Agency continuously monitors the results of the forest regeneration with tough protection.
Sustainable Construction Material
Wood as a kind of sustainable material, one of the most important value is being used to construction field. Actually, wood is a versatile raw material and the only renewable construction material.
Wooden structures are usually characterised by a combination of different components that together deliver the best possible load-bearing capacity, thermal, acoustic and moisture insulation, fire resistance and a long service life.
Increasing the proportion of wood in construction can facilitate a reduction in the use of other construction materials, such as concrete, steel and brick. These construction materials do not come from renewable raw materials, they require a great deal of energy for their production and they entail higher emissions of carbon dioxide.
Another reason about seeing wood as sustainable construction material is that wood can replace other construction materials in many structures while providing the same functionality.
One example is that in the Swedish bridge standards (Bronorm) wooden bridges can be designed for the same function and service life as steel and concrete bridges. Such a material substitution could bring significant climate benefits, where wood replaces materials whose production requires fossil fuels and causes high carbon emissions.
A study has shown that where wood products replace other construction materials in buildings, there is an estimated average substitution factor of 1.6 tonnes carbon dioxide per cubic metre of wood material, which in an industrially produced apartment with a wood frame adds up to 16 tonnes of carbon dioxide.
With greater energy efficiency drives and more climate-smart building, the production phase and thus material choices will take on greater significance, and substitution options will be important.
All construction materials except wood have a single eco-cycle that involves reuse. For wood there are two eco-cycles—ashorter one that reuses the component or material, and a longer one that reuses the constituent parts of the wood material via nature’s eco-cycle.
We see examples of the shorter eco-cycle in the construction industry and in distribution and packaging. Windows, doors and timber can be reused, as can pallets, packaging and cable drums. In all cases, there is an organisation to deal with the products and find new users.
Once wood can no longer be reused or its material recovered, for use in fibreboard and other sheet materials for example, it can still generate energy through incineration. This energy is climate-neutral and is in fact stored solar energy.
To make optimum use of wood in climate terms, it should be carried out in a particular order that is illustrated by the environmental hierarchy for wood.
When choosing between different usage options, the alternative that gives the longest period of use should always be chosen, i.e. the one that is higher up the environmental hierarchy.
Directly using felled forest for energy production is not optimal – although it is naturally still better for the environment than energy from finite fossil fuels. It is important to note that wood never needs to be sent to landfill.
Protecting The Environment
The EU’s long-term plan for a competitive economy with low carbon emissions is called Roadmap 2050. The key driver of this transition will be energy efficiency. A low carbon economy will have much greater need for renewable energy sources, energy-efficient manufacturing of construction materials, energy-efficient structures and low-energy modes of transport.
The construction sector has opportunities over the short and long term to reduce emissions of carbon dioxide through the choice of materials with a low environmental impact and through energy-efficient structures. Increasing the use of wood products is part of the solution.
As a member of the UN, Sweden is involved in the negotiations for a global climate agreement. Via our membership of the EU, we are also signed up to its climate objective to halt global warming.
In 2008, the European Parliament voted through a climate package whose overarching objective is to limit the mean global temperature rise to 2°C above pre-industrial levels. The EU has agreed four targets that must be met by 2020. Based on the first three, these targets are often referred to as the 20-20-20 targets.
(1)Reducing greenhouse gas emissions by at least 20 percent compared with 1990 levels
(2)Moving towards a 20 percent increase in energy efficiency
(3)Increasing the share of renewable energy in final energy consumption to 20 percent
(4)A 10 percent share of renewables in the transport sector
Renewable energy is energy that derives from non-fossil sources. This includes energy from wind power, solar power, hydropower and biofuels.
The EU is involved in negotiations for a global climate agreement. Preventing a rise of more than two deg C in the planet’s average temperature will require a major cut in carbon emissions in the near future, according to a report by the UN’s Intergovernmental Panel on Climate Change (IPCC) in September 2013.
Besides, applying wood into construction field is very positive for the climate. Achieving a climate neutral society depends on greater energy efficiency and wider use of renewable energy sources.
For the construction and real estate sector, this will have an impact on both the production and use phase.
For new builds, this is about the choice of materials and having a construction process with a low environmental impact and an energy-efficient building at the end of it.
For the existing buildings, the focus will largely be on energy efficiencies, since the environmental impact of the construction phase has already happened.
Looking forward to the year 2050, an estimated 80 percent or so of the stock in existence then will be buildings that have already been built today. These must be upgraded to make them fit for the future.
It is therefore no coincidence that the greatest focus is on energy efficiencies. We have chosen, however, to present the case for new builds, as this gives a complete picture of the system for future building design.
Historically, a building’s operational phase has accounted for the greatest energy consumption during the building’s lifetime, and the production phase has been seen as almost negligible.
With the advent of new, increasingly stricter requirements concerning energy use in our buildings, and in an extreme case zero-energy buildings, energy use in the production phase will become increasingly important.
Adapting material choices, designs and production processes to the new conditions is a major challenge for the construction sector. Greater use of wood-based products and wooden structures is a significant part of the solution, due to the material’s carbon storage and substitution effects.
New standards and documents are currently being drawn up as a means of assessing a building’s environmental impact. This work is being conducted internationally, within the EU and in each separate country. In Sweden, SIS is responsible for the standardisation work. The work is being carried out in consultation with businesses and organisations.
In the drive towards the objective that all buildings are built with minimal energy consumption for the production of the construction materials, the construction itself, operation of the building and its demolition and final processing, everyone in the construction process will be affected.
For a new build, the architects need to present facts about the building’s environmental impact, so that the developer can compare different proposals against each other.
There are currently steering documents and standards that are hierarchically coordinated, as set out below.
The basis for all standards on the environment is ISO 9001 and ISO 14001. Then come the standards for life cycle analyses. ISO 14040, ISO 14044 and ISO 14025 describe how to transfer the results from the life cycle analysis to an Environmental Product Declaration.
Product Category Rules (PCR) setting out how to draw up an Environmental Product Declaration are governed by SS-EN 15804 for building products. SS-EN 15978 specifies the calculation method, based on a life cycle analysis, that is used to assess the environmental performance of the whole building.
Sweden’s National Research Agenda
Sweden’s National Research Agenda (NRA) is a joint analysis of priority research areas, carried out by the research community, business and the agencies that fund research.
NRA 2020 contains 19 focus areas that relate to the business world. Three of those focus areas--wood production processes, building with wood and living with wood—are specific to the wood sector.
It has shown that wood is a natural and renewable material that is produced locally for minimum transport needs. The by-products from production are used to generate energy, and the production process creates minimal waste.
The material stores carbon dioxide throughout its lifetime, and at the end of its life it can be used as biofuel to replace fossil fuels.
Wood is historically our most important construction material by far. It retained its importance throughout the 20thcentury, but its use has been confined to smaller buildings, due to building regulations and strong advances by alternative construction materials.
Now, as we continue into the 21stcentury and strive to create a society that is sustainable in the long term, demand for wood-based products is picking up once again in all construction projects. This eco-awareness is reflected in an architectural renaissance for all types of buildings, public and private, both inside and out.