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Fakro Responds to Part L with Roof Window Developments

Part L and J (Scotland) have affected Roof Window specifications, with particular emphasis on thermal transmissions and installation systems.

Fakro Roof Windows has a pro-active Research and Development section which was designing new window constructions even before Part L was adopted. Early windows were single glazed, today double glazed is the norm - but now Fakro is introducing a triple glazed window which the company says will reduce thermal transmissions to virtually zero.

Standard Fakro windows are double glazed using single chambered construction and energy saving panes which are filled with an inert gas such as Argon, each glazed unit achieves a U value of 1.1 W/m2K. This specification is achieved by covering the pane with a silver-oxide coating which is solar reflective, making Fakro windows cooler in summer and warmer in winter.

The new generation of Fakro windows is called PreSelect. These windows can be opened in two distinct ways - outwards from the top, which allows the window to be opened in any position from 0 degrees to 35 degrees, or, via a central pivot option allowing the sash to be rotated through 180 degrees. The selection of the opening method is by a discreet function switch just inside the frame.

Part L also governs the thickness of insulation needed in a roof to achieve the required thermal performance, therefore the construction of the installation system needs to be versatile enough to accommodate differing dimensions between roof surface and decking. A comprehensive range of installation accessories and flashing systems to cope with tiles, slates, corrugated surfaces, single ply or metal profiles are available from Fakro.

Masterframe Measures up to Document L

The task given to the government was to reduce carbon emissions to 12.5% lower than the 1990 level by the year 2010. With 30% of all UK generated CO2 coming from emissions from housing stock, the window industry has been struggling to keep up with the latest revisions of the building regulations. Ray Rabett, Technical Manager for Masterframe Windows Ltd, comments on the predicament: ‘When – not if - the government fails to deliver on its Kyoto protocol commitments, a further tightening of the legislation is inevitable.

‘We’re continually developing the thermal performance of our windows to make sure they’re several steps ahead of legislation. All of Masterframe’s windows meet and exceed the criteria of Part L, by incorporating low emissivity glass. The target U-value for PVC-U windows has been significantly reduced from an average 3.3W/m2K to 2.0 W/m2K. By introducing cost efficient argon gas in our windows we’ve reduced the U-value figure even further to 1.8 W/m2K, as certified by the British Board of Agrément. The average for an existing single glazed non low E timber sash is 5.8 W/m2K – it just doesn’t compare.'

Ray continues: ‘With sash windows the issues are more complicated than most, as homeowners and architects still want the traditional design and charm of sash windows. But we don’t compromise on aesthetics at Masterframe. We put as much effort into refining details like our continuous horns and branded hardware as we do into developing performance.’

For additional information on Masterframe’s products and the company’s compliance with the Building Regulations, email mailto:info@masterframe.co.uk quoting DLFB05 for a complimentary copy of Masterframe’s ‘Doc L explained’ CD, normally priced at £9.95.

Tel: 01376 510410
Web: http://www.masterframe.co.uk

SAS Response to Government’s Curtain Walling Proposal

If the government’s proposed new Part L2 regulations on thermal performance are to be completely effective, it is essential the construction industry adopts a consistent approach to calculating the U-values of curtain walling.

That’s the opinion of Derek Hodgson, technical manager for Senior Aluminium Systems (SAS), chairman of the technical committee for the Council for Aluminium in Building (CAB) and of CAB’s thermal committee for curtain walling.

Said Derek of the government draft: ‘While we welcome the fact curtain walling has been treated as a separate entity for the first time, any regulations governing this will be meaningless unless everyone across the industry calculates U-values in the same way.

‘At the moment there is a lot of confusion about how U-values for curtain walling are calculated as different methods are being used.

‘We also need a more exact definition of curtain walling: when is it a wall and when is it a window? The new proposals confuse the issue and suggest a U-value of 1.6, whatever the size.’

To counter the confusion and introduce agreed guidelines for calculating the U-value of curtain walling, CAB has been working with system companies and other industry bodies to establish a universal system of calculation.

‘At the moment the proposals for curtain walling are for a weighted average of 1.6 and for individual elements to be no greater than 2.5,’ said Derek who says the proposed new thermal efficiencies may be achievable, depending on the curtain wall configuration.

‘What would be more sensible would be to define curtain wall as glazing and opaque panelling and that the overall U-value should not affect the overall performance of the building. This may, for example, allow smaller areas of curtain wall glazing to be treated in a similar way to windows.

‘What does concern me is that not everyone has an open and transparent system of calculation. Many companies are using methods which do not consider the whole picture. Although these are acceptable methods, they tend to produce varied U-values.’

Said Derek: ‘We were greatly encouraged that CAB’s original views and recommendations – as put to the Office of the Deputy Prime Minister (ODPM) through industry advisory groups and expert panels earlier this year – were clearly taken on board in the preparation of these draft regulations.

‘We hope our further input will bring greater clarification and consistency in application of these regulations for the ultimate benefit of the whole industry.’

Tel: 01709 772600

SGG Planitherm®, Clearly the Way Forward

The consultation period for amendments to Building Regulations part L is now closed, so what are the likely outcomes for future legislation? The BFRC Window Energy Rating system is now unlikely to be included in its proposed form and average whole window U-values may yet be lowered to 1.8 W/m2 K for the window replacement market.

Certainly at present, high performance low-E products like SGG Planitherm® Total and SGG Planitherm® Futur N from Saint-Gobain Glass enable a wider range of frame types to comply with current regulations, affording greater flexibility for designs and specifications to architects and fabricators. In the not so distant future, the superior thermal insulation performance of these products will be the minimum requirement for most applications.

The consultation document as a whole clearly demonstrates the government’s commitment to the European ‘Energy Performance in Buildings Directive’ (EPBD) which calls for member states to adopt tighter thermal regulations, taking into account both heating and cooling energy savings.

‘As such, the suggested replacement window U-values may well still be lowered to 1.8W/m2k, bringing English and Welsh regulations in line with Scotland. Certainly the feedback we received during the consultation process suggests that many companies called for such a move. Even if regulations are not tightened this time around, section 6 of the consultation document confirms the intention to raise U-value standards for glazing in 2007, just one year later.’ says Saint-Gobain Glass.

As far as the proposed BFRC Window Energy Rating system is concerned, Saint-Gobain Glass discovered a number of fundamental flaws in the calculations and methodology presented. These findings have been passed on to the ODPM, and a full technical audit has been requested. It is now unlikely to be included in the final version of amended part L.

For new build, where the total energy performance of the whole building is now considered, average window U-values are less relevant. It is clear from all the working examples given in the consultation document that higher performance windows of at least 1.8W/m2k would be encouraged under such a system, as this is a relatively cost effective and practical option for designers.

Longer term, section 6 of the consultation document clearly demonstrates the government’s intention to further raise U-value standards for glazing in 2010. The table of aspirational indicative U-values introduces average standards for windows doors and roof-lights of as low as 1.4 W/m2K.

‘The SGG Planitherm® range is unsurprisingly Europe’s best selling Low-E glass and the UK’s leading soft coat brand, offering enhanced thermal insulation, a remarkably neutral appearance and exceptional clarity. SGG Planitherm® easily fulfils the ever increasing requirements of the customer and that of legislation, representing the clear way forward for the glass and glazing industry.’ says the company.

Pilkington K Glass™ Continues to Satisfy New Buildings Regulations

The Government’s Consultation Document on changes to Building Regulations Part L has now been issued. It confirms that windows that achieve the current Part L U values will continue to satisfy requirements in the future.

With the recent fevered speculation now over, Pilkington Building Products – UK says that it is confident that its Pilkington K Glass™ will continue to be the ideal method to meet current and future legislation, while retaining its status as the nation’s favourite glass.

Pilkington K Glass™ is the most widely recognised consumer glass brand in the UK and it will continue to fulfil the requirements of Part L for many years yet. The glass’ low emissivity improves the thermal performance of a building and provides an effective method of reducing fuel bills. The durability of the low emissivity coating also makes it good to handle and process.

Rick Wilberforce, market development manager, Pilkington Building Products, comments: 'The Consultation Document confirms that replacement window U values will remain at 2.0 W/m2K. For new build, because the requirement is to be based purely on the total energy performance of the building, the requirement for any specific U value will no longer apply. Pilkington K Glass™, the leading product in the domestic market, will therefore continue to fulfil customer and legislatory requirements for many years yet.'

The preservation of the current Building Regulations levels will be welcomed by the glass trade and customers alike. New independent research has shown that consumer awareness of Pilkington K Glass™ is by far the highest of any glass brand. The results also confirm that homeowners are more likely to want Pilkington K Glass™ than any other brand. It also means processors only have to stock a single product that can be toughened or laminated or simply left in annealed form.

Pilkington manufactures a range of low-E glasses, using both hard and soft coat technology. Pilkington K Glass™ incorporates hard coat technology to produce a highly durable thermally efficient coating, whereas the soft coat alternative, Pilkington Optitherm™ SN, can be used to further reduce heat loss from glazed areas and is particularly ideal for large-scale curtain walling applications and other commercial projects. Both products provide excellent thermal insulation and greater comfort for the majority of environments.

Web: http://www.pilkington.com

Part L - The Complexities of the Long Awaited Consultation

In response to ODPM's release on 21st July of the consultation document on Part L (energy efficiency), The Construction Products Association's Industry Affairs Director, John Tebbit, said 'This is an important and complex document that will have considerable impact on the whole of our industry and the wider
environment.

'Together with its sector trade association members, the Association has spent the best part of a year working closely with ODPM on Part L, through the Industry Advisory Groups and other means. Whilst I cannot comment in detail at this time, I am pleased to see that much of this work seems to be reflected in this consultation document. The targets for the overall improvement of buildings'

energy performance of 25% to 30% are certainly in line with the industry's view of what would be challenging but achievable. By setting whole building targets, the Association believes that innovation in products, including renewables integrated into building components, will be encouraged.

'Clearly there are areas that still need further work, particularly the compliance methodology for non-domestic buildings. Another area where the Association will be working closely with the industry and ODPM is the development of 'Model Designs' to enable designers and builders to have simple design rules for a range of buildings that will comply with the new regulations.'

In addition to Part L, the Association is pleased to see that the Part F (ventilation) changes are being consulted on in parallel with Part L as they are closely interlinked.

Tel: 020 7323 3770
Web: http://www.constprod.org.uk

Call Edgetech Now for your Free ‘Get-Out-of-Jail’ Card

The results of a comprehensive test programme presented by the GGF at Glassex 2004 suggest that various configurations of PVCu windows with hard coat low E and aluminium spacer bars struggled to get below the required 2.0 U value.

Warm edge spacer bars, and Edgetech’s Super Spacer® in particular, boosted performance by an extra 0.2 U value enabling all the windows tested to pass the standard with ease. Given that hard coat low E glass and aluminium spacer bars currently represent the bulk of sealed units installed in the UK this is worrying. If warm edge were not available now as a get-out-of-jail card it would be even more of a concern considering the Government’s plan to demand even better energy performance from our windows in changes to Building Regulations.

It is often said that if you want to know what we will be using in the UK in the next few years look at trends in the USA. Currently 90% of sealed units in North America benefit from warm edge technology, and it’s starting to grow fast in the UK.

Those who keep up with developments in sealed unit technology will know Gerhard Reichert, Vice President of Business Development at Edgetech IG Inc., a noted expert on the subject. It is greatly down to Gerhard’s technical expertise and passion for Edgetech’s Super Spacer® technology that the US swung so comprehensively behind warm edge spacer bars. Where and when did warm edge technology develop? How and why did it happen? What are the technical developments that made it possible? How will we cope with further changes in Building Regulations and much lower and demanding U values?

The answers are in the latest paper from Gerhard Reichert, available free of charge from Edgetech on 02476 705570 or here as a PDF.

CAB States Part L Position to Industry

The Council for Aluminium in Building has taken steps to clarify its views about proposed changes to Part L of the Building Regulations that are expected in 2005, following publication of the Government’s Energy White Paper last year.

In a direct communication to the Construction Products Association, the industry body collating the views of the entire building sector, and the Government, the CAB has sought to ensure that the views and concerns of its members are fully understood.

While there is widespread agreement that buildings should be made more thermally efficient, the CAB along with others within the fenestration industry, believes that other elements of a building’s construction must be addressed before further changes to glazing standards are considered. Derek Hodgson, Chairman of the CAB Technical Committee explains: ‘We have stated our position quite clearly. If the Government wants to see further improvements then they have to ensure that thermal efficiency is improved throughout a building. To improve the glazing elements alone is simply not good enough whilst there are still aspects of the building that are not specified, or built, to maximise thermal efficiency. At the end of the day we believe that the reliance on the glazing elements of a building to improve overall thermal efficiency is too high and better thermal efficiency can be gained by addressing the building as a whole.’

‘Our members have invested heavily in improving their systems, many of which achieve a better thermal performance than the standards call for. We believe, and I know we are supported in this by our own members and others in the industry, that to put yet more pressure on companies to make further improvements will ultimately have a very limited payback in terms of improving thermal performance, whilst at the same time will bring significant problems for companies both large and small.’

The CAB believes that a far more pressing consideration has to be in clarifying and standardising how the thermal efficiency is specified and calculated. Derek continues: ‘Our members are repeatedly getting involved in specification issues that arise from Part L building regulations being misinterpreted, which is leading to the wrong specification being written. This situation is wholly detrimental to all parties as it increases costs unnecessarily whilst doing little to improve the thermal efficiency of a building.’

Derek Hodgson concludes: ‘The CAB is highlighting its position to ensure that all of the commercial and practical implications of any changes are fully understood. We will continue to work closely within the prescribed consultation process to ensure CAB members’ views are represented at the highest level.’

A Cold Conundrum Cured

'The puzzle of how to overcome the requirements of Part L has been solved thanks to low E glass and a lot of effort on the part of suppliers of various materials, system companies, fabricators and sealed unit manufacturers. But was that the answer to the ongoing problems and what about the future when the calls for even greater thermal efficiency grow ever louder, as no doubt they will?' asks Edgetech.

The imminent introduction of Part J throughout Scotland, with its requirement for a minimum U value of 1.8, is one example of how the demands for even greater efficiencies will be enforced. From within government itself, suggestion has already been made that sooner rather than later, increased legislation will be forced on the construction industry, including the fenestration sector. This will mean that the insulation values of buildings must improve in an attempt to further reduce greenhouse emissions created by the generation of electricity from fossil fuelled power stations plus the burning of gas and oil in heating systems.

Just how far can the development of glass coatings go before the visibility factor is affected, especially with toughenable soft coat glass? Additionally, will the use of gas inside the unit continue to provide the level of performance required especially when using traditional single or dual seal spacer systems and can the life of the gas content be assured? In other words, will the gas stay in place, working effectively for the lifetime of the unit or might it slowly escape so the thermal efficiency of the units diminish.

However, there does appear to be a 'head in the sand' attitude to the spacer. More often than not it's made from aluminium and used as a hollow profile that acts as a container for the desiccant that absorbs any moisture between the panes. Yet it's well known that aluminium is a superb conductor of heat. There's hardly a better, commonly available material for the job. Simply put, when used in the construction of a sealed unit it sucks the heat from the warm side of the glass to the cold side. As a consequence, energy is lost, the efficiency of the sealed unit reduced and finally, it could well fail the requirements of the Building Standards.

Yet there are excellent, well proven and increasingly used spacers available, such as Super Spacer®, that use proven warm edge technology to prevent heat escape at this vulnerable point. The construction, using a dense, desiccant rich high insulation material practically eliminates thermal transmission across the spacer thereby considerably improving thermal efficiency and overall IG performance. On top of this, there's no concern about gas escape, no visual effects to the glass and building owners can be confident the spacer is working because not only can they see it, they can feel it. The edge is warm and it stays warm.

One other advantage, even when its very cold outside, is the lack of condensation around the unit. This moisture on the glass is caused simply by the condensing of humidity in the air on the cold area of glass immediately adjacent to the aluminium spacer. This is yet another sign of the thermal inefficiencies of aluminium as a spacer medium in an era where manufacturers are striving for greater thermal efficiency.

Hot-box testing is the accepted method of proving the insulation characteristics of a glazed structure, be it a sealed unit or glazed frame. In spite of using inefficient aluminium as a spacer, tests on units with low E glass and often with gas fill shows that a U value of 2 seems to be achievable. This is fine but there appears to be little mention of the lower U values required outside of the current demands of part L. Obviously, this is of great concern to sealed unit manufactures and PVCu fabricators in Scotland and especially system companies who wish to continue the supply of profile into that country.

These companies, and others elsewhere who are taking the long view, no doubt have some concern about the future when the demands of Part L become stricter. As an example, will they need to completely re-design their systems to include more chambers or thermally improve the steel reinforcement? The sheer cost of design, development and tooling is frightening. Yet by focusing on the complete glazed frame with all the glass upgrades and gas fill, and especially using a thermally efficient spacer which will so easily minimise heat loss, the result can be a fantastic and immediate payback.

Eurocell, with its Edinburgh based fabricator Lyten Manufacturing, recently completed a programme of hot-box testing at the National Physical Laboratory. Frames fabricated from standard, steel reinforced, three chamber Eurocell 60mm profiles fitted with units manufactured with Super Spacer and K glass but with no gas fill underwent the regime of the European EN test. The units achieved a U value as low as 1.78.

To reinforce these findings, Plus Plan submitted its 70mm PVCu casement window system also with all units manufactured using Super Spacer for assessment by the British Fenestration Rating Council. The results included in the simulation report, which is fully in compliance with approved document L1 and L2 of the Building Regulations 2001, is significant.

The standard, steel reinforced, Plus Plan frames were fitted with 24mm units in various combinations of hard and soft coated low E glass with the cavities filled with either air or Argon. A U value as low as 1.4 was achieved but in no situation were the results in excess of 1.8.

The same test organisation has conducted similar assessments using the Duraflex 65mm Diamond casement system, one frame with a fixed light and top opening full height casement, the other a full size top hung opener. In both instances, with 4/20/4 units produced using K glass and Super Spacer, the total frame U value was no higher than 1.8W/m2K.

The Glass & Glazing Federation, using the Centre for Window & Cladding Technology are conducting a twenty four month project to assess the heat loss at the insulating glass sealed unit edge. Once again, Super Spacer has shown it self to be ahead of the crowd when it comes to thermal efficiency. In tests to date, of the representative samples of so called warm edge spacers available, Super Spacer has been found to significantly out perform others under test.

The results of these numerous tests prove that overcoming the demands of Part J need not be a puzzle or a problem for those in Scotland or who wish to sell into Scotland. Additionally, it bodes well for the future when the energy saving lobby and Building Regulations demand even greater thermal efficiency.

The implication from these tests is that spacers with a True Warm™ edge, such as Super Spacer, have a significant impact upon unit and total frame thermal performance. But what about durability? Certainly, in the case of Super Spacer, there can be no doubt. Well over a decade of experience through out the punishing winters of North America and Canada has proved its capability. There are companies within the UK who have used the material for over five years without a failure. To add weight to this, during the latter part of 2002, a number of Super Spacer users, who were already accredited to BS 5713, have been processed through the rigours of CEN 1279 with good results. Using industry standard butyl hot melt sealants, each company has gained accreditation to this new standard which replaces the British Standard and will be the only accepted standard for IG units in future.

For high thermal performance, durability, plus compliance to standards, both current and future means that insulating spacers such as Super Spacer appear to be the right materials to use. Suffice to say, with such spacers, the interests of unit manufacturers large and small, system companies, fabricators and building owners are well served.

http://www.superspacer.com.

Super Spacer's Thermal Efficiency means System Companies can Readily meet Parts L and J

Compliance for full frame thermal efficiency to the requirements of the Building Regulations Part L and Scotland's Part J has been confirmed when using Super Spacer, with the completion of simulation testing at the British Fenestration Council.

Plus Plan submitted its 70mm PVCu casement window system with all units manufactured using Super Spacer. The results included in the simulation report, which is fully in compliance with approved document L1 and L2 of the Building Regulations 2001, is significant.

Standard, steel reinforced, Plus Plan frames were fitted with 24mm units in various combinations of hard and soft coated low E glass with air or Argon filled cavities. Because of the material's thermal qualities, 16mm Super Spacer was the spacer of choice. A U value as low as 1.4W/m2K was achieved, but in no situation were the results in excess of 1.8.

The same test organisation has conducted similar assessments using the Duraflex 65mm Diamond casement system. Configuration of one frame included a fixed light and top opening full height casement, the other a full size top hung opener. In both instances, with 4/20/4 air filled units produced using K glass and Super Spacer, the total frame U value was no greater than 1.8W/m2K.

Assessment of these two profile systems supplied by major UK system companies has shown that Super Spacer's True Warm technology is way and above more thermally efficient than any other so called warm edge spacer tested. When Super Spacer made units are installed into standard three chamber PVCu frames the total frame U value more than satisfies the requirements of part L and Part J.

Importantly, with Super Spacer it can mean that sealed units can be manufactured without the need for soft coat low E glass types.

Contact: Andy Jones
Tel: +44 (0) 2476 363614
http://www.superspacer.com

An Outstanding U Value Result for Super Spacer

'Using Super Spacer, independent hot box testing proves total compliance to full frame U value requirements to Part L and Scotland's Part J.' says Edgetech.

In England, Part L dictates a minimum U value of 2.0, but what about Scotland? There they have Part J and from March this year, sealed units and windows generally have to meet a minimum U value of 1.8.

Located close to Edinburgh, Lyten Manufacturing, manufactures sealed units and fabricates using Eurocell 60 and 70mm profiles for the trade market. Early on, the company realised the implications and potential problems with the new regulations and implemented technical research. Lyten's Production Manager Jim King explained, 'There were many different sealed unit combinations available to us, different coatings, sealants, gas filling and so on but they all appeared too involved with long-term implications. Frankly, we wanted something simple that we knew would work and as experienced users of Super Spacer came to realise that the energy efficiency of the material might provide a solution.

'The possibilities were discussed with Edgetech which manufactures and supplies Super Spacer. They have been very supportive providing a great deal of assistance and it soon became obvious there was a good potential for significant thermal improvements. Together with Eurocell, we instigated hot-box tests at the independent National Physics Laboratory, where we submitted one of our three chamber Eurocell 60mm system windows, incorporating 24mm Low E hard coat units.

'To our great delight the results were better than we hoped, coming in at a U value 1.78. We know with the help of Super Spacer we can look forward to the future with a great deal of confidence.'

Lyten uses Super Spacer extensively for the production of sealed units for windows, conservatories and all of its door panels. 'SuperSpacer is excellent for all the shaped units which are often required in these panels. It has great all round versatility and speed, no matter what the application'. said Jim. 'Super Spacer gives us a cost effective sealed unit with a high thermal performance. Super Spacer definitely has The Edge!'

http://www.superspacer.com

Lyten Windows Reach New Standard

Lyten Windows, a Eurocell 60mm Window System Scottish Fabricator, has now achieved the Scottish Building Regulations Part J requirement (equivalent to Part L in England). The company has decided to do this in advance of the legislation, which will come into force in this year.

The Eurocell 60mm Window submitted for 'hot box' testing at the National Physical Laboratory in Middlesex, contained Pilkington K Glass as well as thermally efficient spacer bars. Lyten achieved a u-value of 1.78, which puts the company well inside the benchmark figure.

Lyten which is based in Wallyford, East Lothian, and has been fabricating Eurocell's Window System for over three years now, stated, 'we are very pleased that the window has passed the new regulation in conjunction with Eurocell and are looking forward to developing our customer base as a result of this important achievement.

'Eurocell realise how important the new legislations are for the industry to become more credible in the eyes of the consumer, effectively ridding itself of the 'cowboy element,' which previously existed. We have put tremendous emphasis on achieving all relevant accreditations in the past and that is also applicable to any further introductions in the future.'

'At Eurocell we also recognise the importance of the accreditations to our customer network and will support them wherever we can, Lyten being the latest example.' commented Martin Saunders, Sales Director Eurocell Profiles.

Tel: 01773 842100
Email: mailto:marketing@eurocell.co.uk
Web: http://www.eurocell.co.uk

Taylor Woodrow Becomes First to Offer UKAS Accredited Air Leakage Testing

Companies needing to comply with the revised Building Regulations (Part L) can now receive UKAS accredited air leakage testing via Taylor Woodrow's Technology Centre, Leighton Buzzard, Bedfordshire. The new regulations, which came into effect on 1st April 2002, lay down more stringent criteria for building performance.

Taylor Woodrow claims to be the only company to date that can offer UKAS accredited air leakage testing to meet the requirements of Part L (energy efficiency). As a 'onestop shop', Taylor Woodrow's facilities also include an acoustic testing laboratory to help companies comply with the revised requirements under Part E of the Building Regulations.

'The construction industry is still coming to terms with the practical implications of the revised Building Regulations,' commented Roger Blundell, Taylor Woodrow's director of engineering and consultancy: 'We offer a range of testing and consultancy services to help the industry comply, but the UKAS accreditation gives clients additional reassurance that our air leakage tests are carried out to the highest standards.

Part L requirements
The new requirements under Part L have been introduced to help the UK comply with its environmental responsibilities by ensuring that new buildings waste as little heat as possible. Unlike many other construction tests, compliance can only be confirmed when the building facade is complete- in other words, close to completion.

There are three tests that can prove compliance with Part L. Air leakage testing involves closing all the designed apertures in a building, such as external doors and windows, and sealing the air ducts. A test rig comprising a large fan fitted inside a duct is then fitted to the building via a temporary aperture.

The airflow is carefully monitored as the building is pressurised and a series of measurements of airflow and building pressure are taken. From these, the building air permeability is calculated and compared to target values laid down in Part L.

If the air leakage test does indicate a problem, a 'smoke' test can be applied to pinpoint the source of air loss. This involves releasing a fine fog into the building. The vapour will escape outside through any breaches in the building envelope.

A third requirement under Part L is a statement by a suitably qualified person that insulating material is installed securely and continuously and that the effect of thermal bridging has been minimised. lnfrared thermography - the same technology employed by mountain rescue workers to detect body heat - is used to check this.

In addition to UKAS accreditation, The Technology Centre holds ISO 9001:2000 quality accreditation and ISO 14001 environmental accreditation.

Duraflex Produces Part L Pack

PVCu profile supplier, Duraflex, has produced a Part L pack aimed at fabricators and installers for both its 65mm and 70mm Diamond Suite systems. The new 'Exceeding Standards' CD-ROM and supporting information provide companies with the tools they need to assure householders of the products' compliance with the revised Building Regulations.

The key element of the pack is a certificate confirming Part L compliance. Pre-
printed certificates are augmented by blanks providing fabricators and installers
with the opportunity to create their own branded versions. This is made possible by a series of CD based Microsoft Word templates. Other useful information contained on the CDs includes Part L technical bulletins, configuration tables and a proof statement from Pilkingtons.

'Our Exceeding Standards pack is a continuation of our flexible approach to customer support, which began with our Kit CD-ROMs for creating personalised brochures and other promotional items. It provides companies with a solution that can be tailored to their individual needs, and is designed to underline why the Duraflex Diamond Suite is the natural choice for fabricators, installers and homeowners alike,' comments Neil Roberts, Duraflex Director of Marketing.

Contact Neil Roberts
Tel: 08705 351351
Email: mailto:duraflex-info@cdw.co.uk
Web: http://www.duraflex.co.uk

And so it came to glass: How to Select Insulating Glass for Conservatories

Following its move into the Insulating Glass Unit (IGU) sector with the launch of Conservaglass™, Chris Richardson, technical director of Ultraframe (UK) Ltd, considers some of the factors concerned in the selection of IGUs for conservatories.

As has been discussed many times before in the context of ventilation, management of the conservatory environment is crucial to consumer enjoyment of the spaces - which in turn is critical to the market realising its potential.

Ventilation is a very important element in this environmental management - but it is not the end of the matter. Insulating Glass Units (IGUs) deliver a superb and highly effective contribution too. There is also an implication for the Building Regulations. Part L has obviously been amended in respect of windows (new build or replacement) - yet the vast majority of domestic conservatories don't fall within its ambit. However, this is under consultation and it is expected that the Part L may be amended again in a few years - three to four - to include conservatories. If this happens, high performance sealed units will become a statutory requirement - as well as a desirable one for the consumer.

When selecting IGUs, especially in the context of anticipated changes to Part L, thermal performance is paramount - but it is also important to consider the combination of benefits that a unit offers. Questions to ask are: does the unit offer optimum thermal performance? Does the unit offer optimum reduction in solar heat gain and glare - without adversely compromising light transmission? What guarantees are offered against unit failure - five, 10 or 20 years? Does the unit incorporate ancillary installer and consumer benefits such as 'peel clean' films for protection during transit and installation, or 'easy clean' surfaces?

The selection process may be then further complicated by manufacturers laying claim to performance values which are not tested to industry standard - which makes specific performance comparisons difficult. In this respect, BS Kitemarks are everything.

Insulation characteristics
The insulation characteristics of an IGU are dictated by three things: the glass, the spacer technology involved and the unit 'filling' - usually air. Glass should ideally be coated on the interior face of the exterior pane - 'second face' - preferably with a soft 'sputtered' coat - to create a 'warm' cavity in winter. This is usually a layer of silver - better still, two layers - which reflects solar gain outward, and interior warmth inward. Units with the coating on the third face - the exterior of the interior pane - leave a cold cavity, reducing interior comfort and increasing the risk of condensation in winter. Spacer bars should ideally be stainless steel rather than aluminium. Stainless steel spacer bars have a thermal conductivity over nine times less than that of aluminium - used in most IGUs - and are much more effective. Units should also be selected on the basis of a dual seal which will help protect against unit failure. Filling the unit cavity with the inert gas Argon - which has a thermal conductivity 30% lower than that of air - further reduces heat transfer across the cavity, contributing to an industry-leading U value of 1.1 Wm-2K-1 in an Ultraframe Conservaglass™ IGU.

Winter conditions with no solar load on the conservatory are considered worst case for heat loss. Heat loss is measured by an IGUs U-value - described by the norm Wm-2K-1 - which is the heat flow from indoors to out through the glazed area. The lower the U-value, inevitably the less energy required to heat a given space. The U value of the latest proprietary dedicated glazing systems for conservatories is 1.1 Wm-2K-1, excellent performance in itself - certainly compared to the 1.5 of an Argon-filled Pilkington K glass IGU - but also meaning that they will meet any prospective changes to Part L of the Building Regulations as and when amended in respect of conservatories.

Leading systems - in terms of thermal performance and reduction in solar heat gain - can provide as much as 70 extra hours per month of conservatory summertime usage to the consumer.

Solar heat gain
When referring to U-values, it is helpful to be specific about the criteria applied to assess them. Heat gain - primarily in the summer - is measured by the Solar Heat Gain Coefficient (SHGC). The SHGC incorporates the solar transmittance and the inward flowing fraction of absorbed solar energy off all panes of glass. A roof IGU with a SHGC of 0.35 means that only 35% of the sun's energy reaching the exterior pane is passing through to the interior. A low SHGC prevents excessive over-heating in summer.

Comfort
Comfort is related to the interior glass surface temperature. The nearer the interior glass surface is to room temperature, the more comfortable a person will feel. And, of course, the closer to the glass a person is the more marked - either way - this effect will be. Comfort - and interior glass surface temperature - is a function of U-value and the SHGC. The twin layer silver coating also influences how much - for instance - fading or otherwise occurs to interior fabrics from exposure to Ultra Violet light, twice as effective as hard coat standard IGUs. Obviously, IGUs with a lower U-value - such as 1.1 Wm-2K-1 - are beneficial because they provide higher nighttime temperatures, especially in winter, and reduce solar heat gain in summer.

Other factors
As discussed, the technical performance of IGUs is the starting point in the specification process, not least given the likelihood of Part L amendments by, say, 2005 or 2006. But always look for a combination or package of features that deliver best overall benefits. Industry leading systems now feature enhanced guarantees against unit failure - 20 years should be offered, rather than the standard 5 or 10 years; fitter-friendly benefits such as interior and exterior glass surfaces that 'peel cleaní after installation and - for the consumer - 'easy clean' low maintenance glass finishes to the exterior.

Building Regulations aside, consumer enjoyment of the conservatory is one of the most important factors in ensuring the market grows as it should. Insulating glass sealed units for conservatories enhance this enjoyment no end - and will truly deliver 'a room for all seasons'.
Tel: 01200 452375
Fax: 01200 414646

Growth and Cover for Businesses

Kim Rehfeld, Managing Director of HomePro, looks at the nature, and benefits, of Insurance Backed Guarantees - now necessary for FENSA compliance.

Insurance Backed Guarantees (IBGs) have been in the industry for many years and are viewed with varying levels of scepticism. While few question the concept of IBGs; issues have arisen from the quality of the company supplying them or, perhaps more importantly, that of the insurance company actually underwriting them.

That said, however, it is indisputable that the offering of IBGs beneficially affect the sales conversion process. IBGs are, in effect, a great tool for building businesses and can help increase conversion rates by as much as 30%. Offering financial packages was a key sales converter for many but now that everyone does that, IBGs, while widely available, offer an opportunity to achieve a competitive edge.

The Department of Transport, Local Government and the Regions (DTLR) - formerly the DETR - had suggested, with some reservations, that IBGs are a means of consumer protection. They are mechanisms whereby the consumer can have enhanced confidence in the people working for them, and are a superb method for installation professionals to increase their quote acceptance ratio.

Since the June General Election, the DETR has been renamed as the DTLR. Responsibility for construction will shortly pass to the Department for Trade & Industry (DTI), although the DTLR will still retain control of Building Regulations.

The DETR's position on IBGs had been expressed thus:
'On balance, notwithstanding certain deficiencies, the DETR thinks that proper insurance-backed warranty schemes, which are widely available to consumers through legitimate trade associations (or direct from an insurer), would be of considerable benefit. As a general principle, it appears that they must satisfy four tests if they are to operate effectively:
They must be provided by, or underwritten by, a reputable insurer;
They should meet a minimum standard in which consumers can have confidence;
The sponsoring body must require its members to operate the scheme and offer it routinely to customers; and
They should be written in plain English and clear in their provisions'.
(Source: http://www.construction.dtlr.gov.uk June 2001).

IBGs generally offer three differing levels of assurance: those which cover materials, all completed workmanship and work in progress for up to 10 years; those which offer the same criteria as mentioned before but include deposit insurance for up to 25% of the contract value; and the most comprehensive of all, which includes index-linked cover to ensure future value is protected.

The basic policies cover the work carried under the guarantee, including labour and materials. If the company ceases trading, the insurance covers the cost of completing the project so customers are not left out of pocket. When a project is completed, the customer, generally, completes a job satisfaction slip upon which the insurance certificate is issued.

The next level of cover takes care of homeowners' deposits for up to 25% of the project value and because it is pre-paid by the installer in advance, the cover is instant. This level of cover makes closing the sales process much easier, because customers are so much happier handing over the deposit in the knowledge that it is fully protected.

Inflation-proof comprehensive policies cover all as mentioned above but also protect the future value of the customer's investment. In a nutshell, the maximum amount a homeowner can claim increases each year throughout the policy life.

Commercial work
IBGs value isn't limited to the domestic sector. Nowadays, many local authorities - especially for grant work - and architects insist those tendering for their work provide warranties; and IBGs are much less expensive than industry standard performance bonds. And the assured period is generally longer too. Commercial IBGs cover contractual obligations as well as any additional cost in completing a project if a company ceases trading.

Research has shown that the general public, as well as the window and conservatory industry itself, is fed up with the negative image that rogue traders create. Apart from the need to 'hold one's head up in the pub,' this perception damages all installation businesses, as homeowners view calling someone as a 'distress' purchase and can be reluctant to undertake major improvement works at all, from fear of the hassle involved.
Recent figures show over a quarter of the population have used home improvement services, but over 90,000 formal complaints have been registered in one year alone.

Admittedly, this includes all trades, but by this measure, trades people are seen to be more unreliable, by comparison, to those cheery folk dealing in used cars!
The cowboy will never go away, especially not while there are 'cowboy customers' wanting quick fixes on the cheap. However, there are opportunities, and through warranties, where the true trades professional can encounter decent customers, wanting a good job at a fair price.

HomePro Ltd
Tel: 0870 738 4858
Email: mailto:info@homepro.com
Web: http://www.homepro.com

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