Fri 1 Feb 2008
Window of opportunity
While they let light in, doors and windows now have another role - to keep energy in. Roger Hunt reports.
"Specification of windows and doors will become more complex over the next ten years with the push towards zero carbon homes," predicts Mike Lenehan, architectural design and build manager for David McLean Homes. "Items such as triple glazing, full thermal breaks and super spaces will become standard as we will be required to use super efficient windows with a U-value of less than 1W/m2K in order to reduce the CO2 output of our homes."With the current regulations and market, our main aim is to give customers an efficient, maintenance free, long-lasting, and aesthetically pleasing window to suit their new home. This needs to comply not only with building regulations and British Standards, but also CDM health and safety requirements and the requirements of the local planning authority."
Gary Hutton, general manager of Black Millwork, distributor for Andersen Windows in the UK and Ireland, believes that aesthetics and the convenience factor of low maintenance windows is a very important consideration. "Having already experienced the benefits of low maintenance wood, PVC-u and aluminium profiles, plus a whole host of composites, it will only be a matter of time before housebuyers will expect low maintenance glazing as well."
Andersen is offering its own High Performance Low-E4 self-activating, self-cleaning glass as standard across its 400 Series of windows and patio doors with no additional charge. As part of the package, they also come complete with a factory applied disposable protective film on the inner and outer glass surfaces.
When it comes to energy efficiency and the need to meet the varying levels of the Code for Sustainable Homes, Dareth Daley, sales and marketing director for NorDan, identifies a significant increase in the demand for high performance timber and aluminium clad timber windows.
"Manufacturers have sought to be innovative by improving the insulation of their windows by providing composite windows and by using revolutionary new silicon spacers in triple glazing systems. By replacing the traditional aluminium bar with silicon spacers, thermal efficiency is enhanced and the risk of condensation is decreased."
Whilst the UK standard is currently 1.8W/m2K and the EU is recommending that U-values in windows be reduced to 1.5, NorDan's standard NTech window achieves a U-value of 1.2. However, NorDan's newest NTech window has a U-value of just 0.7. It features a 105mm insulated frame and triple glazed sealed units with low emissivity coated glass which provides a 54 per cent reduction in energy loss.
Timber window manufacturer JELD-WEN has introduced a new range of Regency fire egress windows in order to help developers and contractors meet building regulation requirements. The new windows feature two side hung casements combined with a flying mullion to provide the clear, unrestricted opening required.
Tony Pell, JELD-WEN's product manager, believes that sustainability is leading to a huge resurgence in the use of timber. "Timber is the only truly renewable material for windows and doors that produces much less waste and any waste can be recycled. Use of timber windows helps developers meet their sustainability requirements as growing trees take up carbon dioxide from the atmosphere and lock it up for the lifetime of the timber."
At Premdor, Keith Clark, group product manager, echoes this view. "The evolving interest in timber as the environmentally preferred window material is also enhanced by the high performance characteristics of the modern frame design."
To meet the changing demands of the market, Premdor has introduced the Alpha System RP range; a reversible projecting window system which enhances high performance and security whilst offering new design opportunities for specifiers and architects. With the use of a projecting and reversible hinge system, the windows open through 170ยก for external cleaning within the dwelling.
As members of the Wood Window Alliance and the British Woodworking Federation's (BWF) Window Accreditation Scheme, window and door manufacture Mumford & Wood is involved in an industry initiative to promote the specification of timber windows.
"This is not only about aesthetics but our adherence to work to strict rules regarding the use of sustainable timber and making a very real contribution to improvements in housebuilding delivery in a low carbon environment," says Chris Wood, Mumford & Wood's sales director. "High performance timber windows are taking back their share of the fenestration market at the expense of PVC products."
Mumford & Wood has recently attained the BSI Kitemark of excellence for its range of premium quality timber windows, doors and French doorsets. Awarded under the company's membership of the BWF Timber Window Accreditation Scheme, and in partnership with the BSI Kitemark, this third party certification scheme requires members to undergo a stringent approvals process.At Linden Homes South East, technical director David Evans believes that, from a developer's point of view, the priorities for windows and doors are that they offer a good level of security and are designed in a way that makes them as maintenance-free as possible for customers. "To ensure this we choose materials that are both long-lasting and require minimal upkeep to preserve them in the state they appear upon purchase. This offers our customers a more practical service, saving them time and money in the long-term.
"The fundamental requirement with the material choice for our windows is that it is aesthetical in keeping with the architecture and build of the home and, depending on the style of the property, this represents quite a diverse choice. For example, where one style would compliment a common plastic window, another might require a metal framed design."
Martin Saunders, sales and marketing director for Eurocell Profiles, a supplier of PVC-u window and door systems to fabricators who service housebuilders across the country, notes that many are choosing coloured profiles rather than white. "This is because they are looking to differentiate their properties and many planning authorities are trying to ensure developments fit in with their surroundings."
Another factor influencing housebuilders is increased densities. "Units that offer the same amount of floor space, but with a smaller 'footprint', naturally embody a greater return on investment," comments John Duffin, managing director of Keylite Roof Windows. "Roof windows enable developers to build upwards, increasing the living space."
The Keylite range features a number of different styles of roof window, including fire escape, top hung and centre pivot. The windows can be specified to be electronically controlled, and even rain-sensitive, so that one button can be used to open or close all the windows. Meeting the trend for increased light and extended living space in new homes, the Sheerframe bi-fold door from LB Plastics is available in a range of configurations and spans up to six metres so offers a fashionable alternative to conventional French doors and sliding patio doors.
"PVC windows can make a significant contribution to sustainable new homes if the right profile system, fabricator and installer are chosen," believes Mike Butterick, head of LB Plastics' newbuild division. "With the availability of lead-free, calcium organic stabilised PVC profile and thermally enhanced reinforcement, both of which are recyclable at the end of a long, low maintenance service life, sustainability can be addressed comprehensively."
Made to measure door specialist, Manse Masterdor claims that its new Masterdor Thermal, a 55mm solid, insulated timber door set, is one of the most airtight on the market. Made from engineered timber, it has an insulation foam core that has been proven to increase the door's thermal efficiency to produce a U-value of 1.1.
"Housebuilders are looking creatively at every opportunity to gain green points and we are finding that the doors market reflects this as we see an increase in demand for door products with 'green' credentials," comments Gerry French, product manager for doors at Palgrave Brown.
All the softwood and hardwood used in Palgrave Brown's Scotdoor and Timedor timber doors comes from sustainable sources. The Timedor models are a 44mm blank and now include routered designs that were previously only available within the 60mm Scotdoor range.
Sunfold Systems has recently released new high security aluminium front doors. The aluminium panels and frames are coated in a choice of finishes that are claimed to be not only easy to clean but also extremely durable and robust and have the additional benefits of high insulation and sound deadening. Details in the designs are highlighted through the use of triple glazed glass and stainless steel inlays. "The window and doors industry obviously plays a massive part in the project planning for any housebuilder," concludes Kevin Farrow, design and sales for Sunfold Systems. "We have found over the last year that there has been more and more interest taken in the areas of increased security, product quality and material durability."
First published in Show House Magazine February 2008.
The greatest care has been taken to ensure accuracy but some information contained within this article may have changed since it was first published.
Posted by Roger Hunt
in Black Millwork, Eurocell, Jeld-Wen, Keylite, L B Plastics, Masterdor, Mumford & Wood, NorDan, Palgrave Brown, Premdor, Product Portfolio, Sunfold on Fri 1 Feb 2008
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