4 minute read
Structural timber: delivering quality and sustainability assurances
The Committee on Climate Change has advised the Government to use the coronavirus crisis as a catalyst for reducing the construction industry’s carbon emissions and called for ministers to seize the opportunity to make the industry greener. Andrew Carpenter discusses how structural timber systems can help the UK construction industry deliver both quality and sustainability assurances.
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The world has woken up to the detrimental impact that we are having on the planet. Now is the time to invest in building in timber for not only safeguarding the environment and reaching net zero carbon targets, but also to deliver predictability of quality and performance.
This is a massive opportunity for the UK to make a sizable change and opt for more sustainable building technologies. There is now real positivity around our sector. Structural timber systems are acknowledged as one of the optimum construction solutions in the battle to reduce carbon emissions.
Foundations for timber frame structures can be built at a lower cost and less environmental impact due to the lightweight nature of the structure. Photo: Stewart Milne
Reducing carbon emissions
Trees are at the heart of the climate change debate. Once carbon sequestration was a natural phenomenon only understood by scientists, but this has changed and terms such as ‘carbon sink’ are commonly used in construction. Commercially managed woodlands sequester a third more carbon dioxide than wild forests – so the growing of timber for use in construction is vital in the battle to reduce carbon emissions.
Build process
Modern timber frame structures are precision-engineered, strong and durable. The build method relies on a factory-manufactured timber frame as a means of structural support – carrying the loads imposed by the floors and roofs – before transmitting them to the foundations. The foundations for timber frame structures can be built at a lower cost and less environmental impact due to the lightweight nature of the structure. Timber frame construction uses factory-manufactured wall panels, floor panels and roof panels. The systems used are classified as either open panel, closed panel or structural insulated panels (SIPS). In open panel timber frame structures, the open panel system provides the structural frame, to which site-installed insulation, services and plasterboard elements are added. In closed panel timber frame buildings, the structural frame is the same as an ‘open panel’ construction, but includes factory-fitted insulation and inner sheathing boards to close off the panel. Finally, the SIPs building method uses timber panels, which are bonded to insulation to provide structural strength.
Progress
Around three quarters of all new homes in Scotland are built using structural timber, but England is lagging behind with just a quarter of all new homes being built using structural timber. >>
About the author
Andrew Carpenter Chief Executive Structural Timber Association (STA)
Further information
STA Assure Quality Management Scheme
All structural timber building Timber frame construction uses factory-manufactured wall panels, floor panels and roof panels. Photo: StoraEnso
system supplier members must annually go through an Structural timber is now used by every sector of the independently assessed STA Assure Quality Management construction industry, due to timber’s superb environment Scheme. The process is supportive and informative to credentials – reducing energy consumption across the lifetime ensure that the highest levels of competency can be of the building, as well as being quick and easy to construct. demonstrated by all STA members. Endorsed by all the major warranty providers the STA Assure programme has Quality and accountability different levels of compliance – Gold, Silver and Bronze – depending on the extent of quality systems in place at the Structural timber is not only about sustainability. The messages time of audit. from the Hackitt Review findings mean that the construction industry needs more accountability surrounding the build Competency Scheme for Timber Frame Designers and process. The final report, ‘Building a Safer Future’, outlines ‘the Engineers / Competency Scheme for Installers golden thread’ – a new vision for the building control process, It is equally important for the standards that are achieved in with the aim of increasing productivity, reducing costs and controlled factory conditions to be applied from the design ensuring quality developments. stage right through to construction on site. This is why there is a Competency Scheme for Timber Frame Designers and Quality assurances should be an end-to-end process, and Engineers in the STA Assure programme and a Competency competency and compliance are crucial in achieving excellent Scheme for Installers within our Site Safe Policy. This standards across all construction projects. makes certain that compliance and quality is an end-to-end process. Site Safe Policy has now been mandated by the Summary Health and Safety Executive and is seen as an example for other material groups to follow.
Timber architecture is having its moment; however, it is going to be far greater than that. It is a trend that has major potential for the future of building design and development. Continuous technical developments and the need for sustainable management of resources are further reasons why timber systems are proving to be the material of choice.
Further reading
• Timber frame construction, 5th edition, ISBN 978-1900510-820, TRADA Technology, 2011
Now is the time to invest in building in timber; for the prosperity of the country and its residents, for employment, for the economy and – ultimately – for safeguarding the environment, today and tomorrow. n • Site check: the timber frame pocket guide, ISBN 978-1909594-65-4, BM TRADA, 2018
• WIS 0-3 Introduction to timber frame construction, BM
TRADA, 2020
