Timber and the future of sustainable construction
17 July 2016
Timber, one of the most sustainable building materials, could help solve a major issue in modern construction – helping the UK increase housing stock without triggering significant carbon emissions.
By sector, the built environment is one of the largest contributors to CO2 emissions in the UK. With the country challenged to deliver 200,000 new homes every year just to keep pace with demand, it is new housing developments that will have one of the biggest impacts on our commitment to global carbon reduction targets set in Paris at the end of 2015.
Timber could help tackle these conflicting goals. Not only can it exceed other materials in terms of ease of use and speed of delivery, it is the most sustainable way of creating new buildings.
Timber’s role in the UK
The UK is a global leader when it comes to timber design. Plans are currently in motion for the world’s tallest timber building to be built in London, the Oakwood Tower skyscraper. At 80 storeys, this will dwarf the current highest timber structure, the 14-storey ‘Treet’ building in Bergen, Norway. However, despite such leaps the UK still lags behind international peers in volume of overall timber usage, with a lingering preference for materials with weaker environmental performance, like steel and bricks and mortar.
An answer to the UK’s housing needs
Despite the boundaries of timber construction being pushed to new limits in the commercial sector, it is in housebuilding that it could have the biggest impact – helping solve the challenge of delivering homes more quickly to cope with demand.
Building with timber supports offsite construction methods, which can speed up average build times by a third compared with using carbon-intensive materials like concrete and steel. It also allows for houses to be fitted out immediately, rather than needing lengthy drying processes that are reliant on uncontrollable variables including the typically unpredictable UK weather.
An energy-efficient choice
From an environmental perspective, timber is an energy-efficient material – with thermal insulation far greater than others.
For example, the Balehaus project, a joint initiative by ModCell and Bath University, used compacted straw insulation between timber panels in new home construction. The finished homes saw a 90 per cent reduction in heating bills.
A renewable carbon storage cycle
It’s the carbon-negative nature of timber that sets the material apart. Over a tree’s lifetime, the rate at which it absorbs CO2 gradually slows as it ages. This means that harvesting trees for their wood, and planting five for every two cut down – as sustainable commercial forests do – continues the cycle of carbon storage.
Using wood could actually help establish the construction industry as a net-absorber of CO2 by creating a demand for commercial forestry in the UK. This isn’t simply a commitment to a reduction, it’s a commitment to a long-term CO2 sink that could offset emissions made by other industries.
If trees are harvested every 40 years, one hectare of commercial forestry could have captured and stored 483 tonnes of CO2 in this time. The absorption mechanic for these trees far outweighs the amount emitted during the construction process – including transportation, manufacturing and assembly. In essence, creating a timber-constructed home is a carbon-negative process and the wood used represents a net-absorption of 19 tonnes of CO2 and the typical estate of 84 homes equating to 1,602 tonnes.
A high-performance material to meet future needs
In addition, timber design can be used to create beautiful structures, particularly popular in schools and specialist medical units for its calming qualities. The variant aesthetics of wood can be used in combination to create truly unique and stunning designs, perfect for standout projects.
With new innovations constantly being developed, such as recent breakthroughs in making wood transparent, the design possibilities are endless and all contribute towards sustainability.
The ability of wood to help foster a low-carbon economy should not be overlooked. It’s a naturally abundant and renewable material and can help us make great strides in addressing the dual challenge of creating more homes and reducing CO2 emissions.
Christiane Lellig, Campaign Director at Wood for Good – the timber industry’s sustainability campaign