Clearview South March 2014 - Issue 148 - Page 32

doors&windows MEETING THE CHALLENGES Do U-Value DSERs? Expert guidance is always welcome: in this article, Mark Barsby The VEKA UK Group’s Head of Technical, explains what you need to know on what is undoubtedly a confusing and complex issue. The expected changes to Building Regulations Approved Document L in England (which set minimum requirements for thermal performance of windows and doors) - after much anticipation, promises of release dates which came and went, and one false dawn after another - were finally published last November. Apologies for the history lesson, but for those who have more exciting things to do with their lives than I do: Approved Document L has been split into four sections covering the various types of new/existing buildings both domestic and non-domestic for a while now. Unlike previous amendments to Document L, this time around only two of the sections appeared to be updated, which both covered new buildings. We concluded, therefore, that come April this year when any changes came into effect, for most of the window and door industry no changes were required in performance for replacement windows and doors from the current requirements. A re-cap for those who haven’t got this imprinted in their brain: for windows this is a minimum Window Energy Rating of Band C or Value of 1.6 W/m2k; and for doors a minimum U-Value of 1.8 W/m2k. While an Energy Rating Scheme (DSER) exists for external 32 MAR 2014 doors (for those of unsure of the acronym it stands for DOOR SET ENERGY RATING) it is not currently included as a method of compliance in Building Regs. It is a purely voluntary scheme. The rumour mill had been circulating for a while that DSERs may be included in the amended Document L, but when the two sections dealing with existing buildings were not updated and published it appeared that the rumours were unfounded. Or so we thought! It wasn’t until you read the small print at the bottom of the page on the Planning Portal (http://www.planningportal. gov.uk/buildingregulations/ approveddocuments/partl/ changes that there was an additional document titled 2013 Amendments to Approved Documents L1B and L2B 2010 Editions. Buried in the text somewhere at the bottom of page 5 in table 1, it now includes the alternative of being able to certify a door for Building Regulations with a DSER of Band E or better. So there we have it! From April this year, you will be able to certify your External Doorsets with a DSER as an alternative to a U-Value of 1.8 W/m2k. So what will that mean for the industry? While I don’t own a crystal ball, we can look back at the evolution of the Window Energy Rating Scheme for some clues. WERs were included in Building Regs as an alternative method of compliance to U-Values back in 2006. Before this, there was a great deal of interest in the WER scheme, but it was seen as a differentiator and a route to market used by a relatively small number of fabricators and installers. While the inclusion of WERs in Building Regs was not particularly smooth and created some animosity at the time, today they are used as both a compliance and selling tool by the majority of fabricators and installers. We are comfortable with WERs and are able to use the recognisable label as a method to clearly demonstrate the thermal performance of our window to customers and consumers. At The VEKA UK Group, to this point, we would readily admit that whilst the DSER Scheme has been around for a while, there has been little interest in it and from the few enquiries that we have had, most do not lead to certification. However, if we look back to when WERs were first included in Building Regulations... I think we can expect more interest and increase in demand, particularly as awareness begins to circulate the industry that DSERs are now included in Document L. However, there will be challenges and education needed. DSERs for entrance doors cannot be presented or sold in the same way as WERs, as solar gain is not included in the calculation. The Minimum WER is a Band ‘C’ and the minimum DSER is a band ‘E’ and if you glaze your windows and doors with the same glass sealed unit, they will not achieve the same result. How will we explain that to our customers - and present a coherent sales pitch? Just to make things more complicated - DSERs can be applied to Patio, French and BiFolding Doors which DO include solar gain in the calculation. It is, therefore, unlikely that all types of door will have the same DSER band. ‘our industry will find a way through the maze – we always do!’ Complicated! One thing is for certain, however, our industry will find a way through the maze – we always do! We continue to support customers of both the VEKA and Halo brands to find a way through the maze with practical advice, as we did with CE Marking last year. There are many issues surrounding the thermal performance of fenestration products and it continues to be both a diverse and complex subject. That is why we will be supporting the industry forum ‘The Triple Glazing Question’ to take place at The Ricoh Arena, Coventry on 10th April. Follow Mark on Twitter @MarkBarsby1968 via #tripleglazingq as they prepare to present the arguments for and against Triple Glazing for PVC-U windows. To read more, visit www.clearview-uk.com