A recent article published by an alliance set up to represent the traditional construction industry claims that the timber frame market share in the UK is currently the lowest it has been in many years - the online article also stated that traditional methods of construction offer better sustainability at a lower cost. Contrary to this, the Structural Timber Association (STA) released figures at the beginning of this October, confirming a record number of orders for the timber frame sector last year - with some companies seeing a 100% increase in business and continued growth in 2014.
Simon Orrells recognised the potential of offsite construction methods when he started his company, Frame Wise, in the early 1990s. Simon offers his perspective and explains his views on why the timber frame industry is at its strongest to date.
“System specification is key to success when creating an energy efficient, sustainable building. One main decision that architects and specifiers face is the choice between traditional and modern methods of construction. Understanding and addressing the gap between projected and actual performance is an industry-wide challenge and there are multiple house building delivery routes which makes mapping the process a complex task.
The STA has stated that the timber industry has reported increases in sales of up to 163% in recent months. These figures are a direct result of the widely reported shortage of materials in other sectors and the recognition that timber brings speed of build as well as superb energy efficiency. Timber Frame is widely acknowledged as being the most economical and efficient method of construction – offering greater quality achieved through offsite build methods in controlled factory conditions and the ability to offer greater choice and adaptability.
Factors that drive energy efficiency are bespoke specification issues such as levels of insulation and airtightness. There is growing evidence of a gap between the as-designed and as-built energy/carbon performance of new homes and timber frame offers considerably more certainty when it comes to delivering as-designed performance, with U-Values that are significantly easier to predict.
The minimum U-Value required in the external walls of a new-build house is currently 0.30 W/m2K and timber frame solutions are often able to achieve less than 0.10 W/m2K – with blockwork home suppliers only claiming around 0.25 W/m2K, meaning that timber frame structures vastly outperform traditional methods of construction in this area. Timber frame buildings are also sealed preventing moist air from reaching inside the building and keeping the warm air within.
It is clear that using prefabricated timber frame provides a faster speed of build than traditional block methods of construction – typically 30% quicker. Timber frame construction is not weather-dependant, which makes project planning more predictable and reduces risk of setbacks. Many construction follow-on trades, such as electricians and plasterers cannot work in exposed weather conditions and therefore cannot start until the interior is protected from the elements. These trades can start much earlier in the construction programme of a timber frame house, which means that the building can be finished sooner. This in turn allows for faster return on investment when it comes to commercial housing. Timber frame providers are able to erect an average four bedroom house, whilst making it watertight, in just seven days - a claim that is far beyond the capacity of any traditional methods. Houses with all-masonry walls require a longer period for mortar and plaster on the inside to dry out - extending the build time by several weeks.
Timber frame is now the UK’s fastest growing method of construction and a core reason for this is the sustainability benefits it delivers. The latest building regulations demanding the use of more sustainable materials makes this a major factor that cannot be ignored. Timber delivers a high-performance building solution that directly contributes to achieving high Code for Sustainable Homes levels. Timber technology allows for Excellent/Outstanding BREEAM ratings for commercial buildings and demonstrates a high commitment to environmental best practice and Corporate Social Responsibility. The Fabric First Approach, adopted by Frame Wise, creates a high performance, thermally efficient building envelope that can meet higher levels of Code, without the need to rely on expensive energy-saving bolt-on technologies, such as solar panels.
Structural timber is sourced from managed forests, making it highly renewable and sustainable. Planting trees for the production of timber benefits the environment and its harvesting, production and transport are seen to produce less CO2 than traditional construction materials.
In contrast, sourcing blocks means relying on the extraction of raw materials from the earth which have to be mined, transported, combined together and will ultimately run out. Producing raw materials also creates waste, however, there is almost no waste in timber production and even sawdust is used for chipboard or paper production.
The claim is that the traditional construction industry is pulling together to counteract so-called misplaced perceptions on modern methods of construction; however, I would have to agree with Andrew Carpenter, Chief Executive of the STA who states that STA members are now witnessing the fruits of their labours. As an association, the STA have worked hard to build an understanding of timber in terms of sustainability and performance, coupled with the relationships they have forged with other organisations. As we now see the industry recognising that timber is the way forward for all these reasons and learn that stocks of brick and block, as well trained bricklayers are in short supply, it is no wonder that the time for timber has come.
As far as I’m concerned, the future is hugely positive for the timber industry and it is extremely exciting to be a part of this. With consumers recognising the advantages of offsite construction, this is an industry that will continue to thrive."