Aug 23 2006
Radical changes to Part F of the Building Regulations for Northern Ireland, which come into force in November, will mean for the first time low-e glass will effectively be mandatory for all new and replacement windows. Pilkington Building Products UK has a simple solution to ensure compliance in one easy step.
Rick Wilberforce, Market Development Manager-Europe, Pilkington said, “While the changes to Part F will be far reaching and have a significant impact on glazing specifications, the use of Pilkington K Glass should ensure that all windows satisfy the requirements. And by specifying a hard coated product, you’re guaranteeing that it is tough, durable and easy to process.”
Although the technical detail of the new Part F is yet to be published, an announcement made by Department for Finance and Personnel Northern Ireland in March made it clear that, for new buildings, compliance will be achieved on the basis of the total CO2 performance of the building. However, the maximum allowable U value for windows will be 2.2, meaning that ordinary double glazing is no longer permissible in new buildings. For replacement windows installed in existing buildings, it is likely that a U value no greater than 2.0 will have to be achieved. Both these requirements are easily met with windows using Pilkington K Glass.
With the new requirements for replacement windows will come a new route to compliance; the Window Energy Rating (WER). WERs were launched by the British Fenestration Rating Council (BFRC) in 2004 but came of age in April this year with the changes to Part L in England and Wales and now in Northern Ireland with Part F.
Rick Wilberforce explains, “WERs is a system for assessing and labelling windows in terms of their energy performance. The concept was developed because it was recognised that the traditional U value is an incomplete reflection of the impact that windows have on the energy performance of dwellings. Indeed, it was recognised that lower or better U values could be counter-productive if a low-emissivity coated glass sacrificed valuable solar gain as a result. Taking account of this solar gain, and the ventilation of the window frame, results in a more technically correct, and a much fairer, method. Using WERs, both hardcoat low-E and softcoat low-E glasses allow windows to achieve the same performance band. The choice of low-E glass has little effect on the performance band achieved, but choosing low-E glass has a greater impact on the product processing costs. Softcoat low-E glasses require equipment investment, longer toughening cycle times and a much higher degree of car! e and attention due to the relatively fragile nature of the glass coating.”
The BFRC rating also demystifies the energy performance of windows for householders. The BFRC rating value can be converted to a letter on a scale of A to G. The resulting label, which can literally be applied to a window, looks the same as the labels used to rate the energy performance of other domestic goods, such as fridges, washing machines and light bulbs. The public is already familiar with this type of rating and label, and understands that A-rated goods are energy-efficient and G-rated ones are not. This allows WERs to be used both as a demonstrator of Part F compliance and a product differentiation tool. WER labelling recognises and promotes added value windows ultimately to allow consumers to choose between windows on the basis of their energy performance via a single standardised measure.
“And we have already seen the first A rated windows. One such window, created by Piper Double Glazing using Pilkington K Glass and Pilkington Optiwhite low-iron glass, achieves the highest WER band. The accomplishment is all the more impressive as Piper Doubling Glazing used standard technologies and products”, concluded Rick.
Pilkington has produced a special bulletin to explain WERs, the developments over the last few months and the current situation. To obtain a copy go to the Pilkington website http://www.pilkington.co.uk/WERs