You would have to have been living on Mars not to know that the buzzword of the day is “sustainability”: the concept – and the practice – permeates virtually every facet of everyday 21st century life.
Windows are no exception and a recent conference, “21st Century Timber Windows” staged by the British Woodworking Federation (BWF) and its Timber Window Accreditation Scheme (TWA), left delegates in no doubt that today’s wood windows are capable of outstanding performance, durability and sustainability.
However, as BWF chief executive Richard Lambert acknowledged, it’s a message that hasn’t always got through to end users, many of whom harbour the misconception that timber windows are low-tech and who consequently have low expectations of them. “We accept technology as part of our lives and expect it to move forward,” said Mr Lambert, “so why does everyone assume that timber windows haven’t advanced?”
According to Mr Lambert, today’s headlines should read that timber windows are modern, efficient, sustainable and fit for purpose; that as technology advances, so wood windows improve; and that timber windows can make a major contribution towards sustainable building.
Huge advances
And, in detailing the history of the various standards that have applied to the product over the past 60 years, Mr Lambert illustrated the huge advances that have been made in timber window technology. The first standard, BS 644 in 1945, for example, had prescriptive dimensions, single glazing and weatherproofing was provided by “tight fit, with the paint providing the seal”. There were no rules on timber grading, either.
Today’s timber window, he said, was a completely different animal, produced on demand, from knot-free timber (often engineered or modified), factory-glazed (with double glazing as standard), with dry glazing and drained and vented systems, fully factory finished, with enhanced security – and all with external quality assurance and certification.
Possibly the biggest issue for the timber window sector is durability and the public perception that wood windows need frequent maintenance, but Jon Aldenton, chief executive of The Environment Trust, the charity behind the Green Homes initiative, begs to differ.
The trust was behind the 21-year-old Mile End Ecology Park, which, said Mr Aldenton, included some of the first carbon neutral buildings in the UK. He reported that in those 21 years, the timber windows have only had to be re-stained once.
“Durability has been the greatest challenge [for timber windows] and this is where most improvements have been made,” he said. It has been enhanced by manufacturing processes which incorporate full factory finishing including superior spray coating technology.
“I’m a big fan of timber windows and have been for years,” he continued. “And I’m not afraid to knock PVCu windows – even major NGOs such as Greenpeace and WWF prefer timber over PVCu.
“The rate of construction is one indicator of a nation’s economic prosperity but it doesn’t have to be at the expense of its environmental prosperity,” he said, reminding delegates that “timber is the only material to feature specifically in the Code for Sustainable Homes”.
Analysis
The NGOs’ comparison of timber versus PVCu windows includes analysis of whole life costings (WLC) and life cycle assessment (LCA), subjects which also preoccupy the BRE and affordable housing specialist Lovell Partnerships Ltd – the latter for entirely pragmatic reasons.
As Jane Anderson, author of the BRE’s Green Guide to Specification, explained, the Showcase Project, a study of the LCA of timber windows, looking at issues such as durability and environmental impact, has been a seven-year collaboration between BRE and the BWF.
The project, which will result in a “robust, detailed assessment”, has already led BRE to publish revised service lives for timber windows in the Green Guide – it now judges TWA windows to have a service life of 35 years and non-TWA windows of 30 years.
The full results of the Showcase Project are still being finalised but will be published shortly and BRE’s head of timber division, Ed Suttie, believes they will show that “durability and maintenance are issues that can be managed and robust new technologies are being fostered”. And, he added, “service life is at the core of sustainability”.
For Rob Worboys, Lovell’s central procurement manager, WLC is a crucial part of the building component selection process but remains something of “a black art” as each element is so variable. “Every site, every manufacturer and every client is different and each has a different set of expectations,” he said, concluding that, depending on specification, WLC can work in timber’s favour.
However, for Lovell, the issue is not just the service life of timber windows, but the service provided by the manufacturers. The industry is “behind the ball” in terms of becoming BFRC-accredited, for example. “There are lots of A-rated PVCu windows out there and only two A-rated timber windows, which is an indictment of the industry,” said Mr Worboys. “We need that product.”
And he also threw down the gauntlet in terms of design and installation. Illustrating his point with an image of a nine-storey oriel window, he told delegates: “That’s what timber window manufacturers are going to have to provide for us. Either catch up with what the market wants, or educate the market in what it can have – I’d recommend the former.
“The timber window industry needs to move to a solutions provider role, particularly in supply and fit. There are too few window manufacturers offering installation.”
The message hit home: “Our industry has everything going for it,” said Richard Lambert, “but we must recognise and respond better to the changing requirements of the market, providing the solutions, innovation and flexibility that it demands. If we want to make timber windows the first choice for specifiers we have to make it easier for them to choose timber windows to the specification they want, rather than the one we have.”
Something that should make specifiers’ lives easier will be a web-based tool devised by Wood for Good, as its marketing consultant John Fletcher explained. “The Carbon Footprint Indicator compares the carbon impact of a building element, such as the foundations, walls, floors, doors and windows, roof and so on,” he said. And while BRE’s Green Guide, which uses the Ecopoints system, outlined by Jane Anderson, compares the performance of different materials, the Carbon Footprint Indicator compares “apples with apples”. The tool will be launched at BRE OFFSITE 2007 from June 11-14.
Sustainability
If it’s down to a question of enthusiasm for sustainability, then the construction industry as a whole has it in spades, according to Rita Singh, environmental and industry performance director of the Construction Products Association. “There’s plenty of drive from the industry – we just need to capture it,” she said.
“There is no lull in construction,” said Ms Singh, going on to cite targets such as the 2012 Olympics, and the government’s schools, hospitals and housing initiatives.
“There are also plenty of challenges,” she added, “because sustainable building must include economic and social considerations as well as environmental ones. The construction industry has an impact and a role in addressing these challenges because its end product allows society to function.”
In summing up the progress of the TWA Scheme, its product manager Ruth Soundarajah said that the conference was just the first step towards new initiatives to promote timber windows. These would include advertising – crucially, to installers, who are seen as being key to the consumer market – and publications, including The Essential Guide to Timber Windows.
“We have a vision of a quality window market where timber is the first choice, a mission to change the face of wood windows and values of integrity, accountability, enthusiasm, unity, ambition and eco-friendliness,” said Ms Soundarajah.
“Watch this space for the Wood Window Alliance,” she continued. The alliance will be a joint marketing effort bringing together elements of the timber window supply chain, including raw material suppliers, manufacturers and installers.
“The time is right for the timber window industry to come together to promote the qualities and benefits of modern timber windows. The opportunities are enormous and by working together we can really make an impact on the market, communicating their outstanding qualities and making them first choice in a world where sustainability, durability and easy maintenance are top of the specification agenda.”
