Stewart Milne Timber Systems invited the construction press to its £10m Witney factory at a time of increasing government emphasis on the role of housebuilding in stimulating the economy.
In a government reshuffle construction minister Mark Prisk took over the housing minister’s job from Grant Shapps, while new announcements to boost housing and ease planning have grabbed the headlines.
Alex Goodfellow, group managing director of Stewart Milne Timber Systems, welcomed Mr Prisk’s appointment.
"He comes with some sort of construction experience as a co-chairman of the Green Construction Board," he said. "At least we have someone that is not from an alien sector."
Mr Goodfellow, a new board member of the UK Timber Frame Association, said he welcomed any government initiative that boosted housing. "Two million people are on housing waiting lists and we have the lowest housing production rates since the 1920s."
Despite the UK housebuilding malaise, Stewart Milne is keen to demonstrate it is moving forward, with several recent successes under its belt. They include becoming the first timber systems manufacturer to achieve Buildoffsite Property Assurance Scheme (BOPAS) certification (for its Sigma II build system), delivery of a large Commonwealth Games accommodation project in Scotland and a string of product developments.
The BOPAS certification, backed by the UK’s four largest mortgage lenders, aims to simplify the process of obtaining mortgages on innovative building systems, providing 60-year assessment durability and high levels of mortgage assurance to give confidence to lenders and homebuyers.
Meanwhile, the Commonwealth Games contract involves supplying and erecting 184 timber frames in the Athletes’ Village in Glasgow and is due to complete next summer.
Demand for quality
"Cash flow is king and customers are demanding quality more than ever, but I believe there has never been a better time to use timber frame," said Mr Goodfellow.
He counters the view, sometimes promoted by the masonry industry, that there is no need to build quickly in the current economic climate.
"You do need to build fast," he said. "We can do a nine-week build programme for a medium-size timber frame house. When banks are looking at housebuilders they want to see them turnaround cash as quickly as possible."
Mr Goodfellow said the cash flow benefits of building quickly outstripped any advantage of "steady" masonry building.
Milne believes the likely introduction of thermal testing on new housing will also benefit timber frame construction. "The next thing will be testing of the thermal envelope so they perform to the levels advertised," he said, adding that timber frame’s "fit and forget" solution was well-placed for such a scenario.
"We have a house-buying public that is becoming more tuned in to the rising cost of energy," added Mr Goodfellow. "When they’re selecting new homes it is becoming a greater factor in their decision-making."
Thermal performance monitoring results on Milne’s AIMC4 project will be published shortly but initial findings suggest it has exceeded its targets. Milne’s involvement in the AIMC4 consortium, which is building Code for Sustainable Homes Level 4 homes using a fabric first approach, involves using its Sigma II timber build system on several sites.
Crest Nicholson and Barratt Developments are also part of AIMC4, using Kingspan TEK structural insulated panels (SIPs) and thin joint masonry respectively.
"By the end of 2013 we will have complete documents, evaluating its performance," said Stewart Dalgarno, Stewart Milne Group’s director of product development.
He said the need to focus on "fabric first" – making sure the structure above all else is inherently energy efficient – was confirmed to Milne in its Sigma prototype house project at the BRE Innovation Park, which featured a range of bolt-on renewable energy systems.
"Bolt-on renewable energy systems were technically challenging, with concerns about their longevity and potential legacy problems," said Mr Dalgarno.
Milne has thus invested several million pounds on product development – including new open panel options, in recognition that the vast majority of the market still uses open panels. One is an 89mm-deep panel which can achieve a U-value of 0.16W/m2K when combined with an insulated plasterboard internal lining and mineral wool between the studs.
A new party wall – to be launched early in 2013 – is one of Milne’s newest innovations. It was shown at Ecobuild this year and has been trialled on three sites in Scotland, achieving 5dB lower than the Building Regulations, and is now in final field tests. A patent application has been lodged and Milne is looking to secure BBA accreditation soon.
Mr Dalgarno said sales directors could see many financial savings because using a shallower wall across a row of 10 terraced houses equated to a good cost savings.
It’s not just solid wood studs being used in wall panels. Sigma II C-studs comprise two 38x63mm C16 softwood timber flanges joined by 9mm OSB (either 235mm or 195mm wide) and can reduce thermal bridging and incur 50% less shrinkage, giving the potential to build to increased heights.
Home-grown timber and UK-manufactured OSB in the C-stud also help reduce a building’s carbon footprint.
But it’s not all about products; Milne also puts a big emphasis on the build process.
Airtightness and compatibility issues can arise where developers buy their windows and tapes from different sources. Milne’s research has led it to use a plastic bracket fitting system to optimise the window installation process.
"When times were good people weren’t chasing down every penny, but now they are," said Mr Goodfellow. "It’s the hidden costs that these solutions are able to eliminate. If you can save 25% in your process, then you can pay for your triple-glazed window."
