Summary
¦ The timber frame industry must promote more than just its green credentials.
¦ Timber frame accounts for 25% of new builds.
¦ Achieving CSH levels is cheaper in timber frame.
¦ The UKTFA’s Fabric First campaign has a website www.fabricfirst.co.uk.
¦ The UKTFA’s Q-Mark schemes have been transferred to BM TRADA’s Q-Mark.

When considering the benefits of using timber frame as the core building envelope we should look past the obvious ‘green’ argument. By now, just about everyone from specifiers to builders understands timber frame’s unrivalled sustainability and green credentials. However, to become the number one construction method of choice, timber frame must face its rivals head on, looking at more than just the environmental factors.

We must think about how timber frame works in real world situations: its thermal performance; the financial benefits, and how easy it is to work with if we are to truly understand why timber is not just the future of the construction industry, but the here and now.

Timber frame is going to win the argument, not with rhetoric or vitriol aimed at highlighting the deficiencies of its competitors, but with cold, hard, indisputable figures; so let’s start with a few.

Timber frame’s share of the construction market continues to increase year on year; currently 25% of all new builds use timber frame. This figure alone indicates timber frame must now be considered a mainstream method of delivering quality construction.

Code for Sustainable Homes

A two-year continuous assessment of timber frame homes built at the BRE Innovation Park has shown unequivocally that timber frames are ideally suited to the Code for Sustainable Homes (CSH). It is no surprise that the first homes reaching Code levels 5 and 6 were timber frame buildings. Timber frame is a perfect fit with the low carbon agenda and more and more architects appreciate its benefits, finding it much easier to achieve very high insulation levels, fewer defects and increased airtightness, all with extremely low embodied energy.

The priority now is getting the fabric of a building right, which is great news for timber frame. The importance of the building fabric in delivering sustainability and energy-efficiency benefits is at the heart of a new website launched by the UKTFA. The site, www.fabricfirst.co.uk, highlights the benefits of using timber frame as the core building fabric.

The CSH is shaping the future of construction along with the former Labour government’s target for all new homes to reach Code level 6 by 2016. This will only be possible if the right choices are made now. To achieve the right number of credits to demonstrate compliance with the Code, the construction method chosen by architects appears to be affected by two key factors: energy efficiency and the environmental rating, and sourcing of the building materials themselves. The environmental argument has already been won by timber, so the emphasis should now be placed on energy efficiency and the financial implications of ignoring timber’s advantages.

Technical benefits

A report commissioned by the UKTFA and Wood for Good, revealed a barrage of technical benefits in choosing timber over masonry when aiming for Code compliance. The Comfort and Cost report, based on research by ESD and Buro Happold, explains how to gain credits in relevant sections of the Code, particularly heat loss parameters.

Importantly, this report measures the costs of compliance, comparing timber frame with more traditional construction methods. The higher the Code level attempted, the more it will cost; that’s obvious, but what’s not obvious is that the percentage uplift in cost for each Code level will always be higher for masonry buildings than with timber frame buildings. To uplift from the current building standard to Code level 5 will cost 8-24% more in timber, but 10-30% in masonry – a not inconsiderable amount when multiplied by tens of thousands of new buildings.

This report also highlights that timber frame dwellings generally show a lower additional cost to achieve compliance with a Heat Loss Parameter (HLP) of 1.3, 1.1 and 0.8 than a typical masonry dwelling, with the cost differential assumed to be in the order of 2.2-5.2%, depending on the type of building.

It would be simple to think the case for timber frame is overwhelming and conclusive, but every genius has a flaw and timber frame is no different. In recent months, fires on construction sites in London have brought into question the use of timber frame in multi-storey buildings.

Safety measures

Firstly, it has to be stated that most construction site fires, irrespective of construction method, are treated as arson and therefore the problem is not an inherent issue with timber as a construction material. Secondly, timber frame appears to be vulnerable only for a small window of opportunity during the construction process and the UKTFA has initiated its SiteSafe campaign to educate the industry to this danger and how a few simple steps will dramatically reduce the risk of fire on construction sites.

So, the real question is: do today’s architects, builders, developers and building authorities know how to overcome any weaknesses, maximise strengths and generally use such materials in a way that our buildings are safe, robust, durable and fit for purpose throughout the entire construction process? The answer is yes. We have centuries of experience of building with timber in the UK and some of the most stringent building regulations and standards in the world. These regulations do not differentiate between types of construction, with timber buildings meeting exactly the same fire safety standards as masonry or steel frame buildings.

Q-Mark certification

Adhering to the highest possible standards available has also recently seen members of the UKTFA transfer their certification under the former UKTFA Q-Mark and Q-Mark Plus schemes to the new BM TRADA Q-Mark for timber frame. The UKTFA took the view that certification under a truly independent third-party scheme would give members the best possible credentials.

So, while it would be easy for the detractors to invent reasons to reject the use of timber, that would be missing the point and show a lack of appreciation of the bigger picture.

This is about more than their losing sector share; it’s about the wider implications for the global community and the need to cut energy use and focus all our efforts on using sustainable building products for the benefit of the entire planet.