Fire resistance testing represents a significant investment for doorset manufacturers. However, the commercial value of a successful test extends beyond the performance of the individual specimen. By considering the direct and extended application of test results during product development, manufacturers can establish the evidence required to support a wider range of product configurations, potentially reducing additional testing costs and improving their ability to respond to customer requirements. Understanding The Limitations of a Fire Resistance Test BS EN 1634-1 specifies the method for determining the fire resistance of door and shutter assemblies and openable windows. The test establishes the performance of a particular assembly under standard test conditions. For doorsets, this includes the interaction between the door leaf, frame, glazing, hardware, seals, supporting construction (the wall) and installation details. Changes to these components can influence fire resistance performance. For example, increasing door leaf dimensions, modifying glazing arrangements or substituting hardware may affect the behaviour of the assembly during a fire. Consequently, a successful test does not automatically establish equivalent performance across every configuration within a manufacturer's product range. The extent to which test results can be applied to alternative configurations is determined through the applicable classification and field of application rules. Direct Field of Application BS EN 1634-1 includes a direct field of application that defines permitted variations to a tested construction, subject to specified conditions. The application of these provisions requires competent technical evaluation of the test evidence and the relevant classification requirements. This is documented through a classification report prepared in accordance with BS EN 13501-2. The report establishes the applicable fire resistance classification and identifies the field of application, including permitted variations from what was tested. Where variations are supported by the direct field of application, they can be included within the classification without additional testing, provided all relevant conditions are satisfied. However, these provisions are specific. They do not permit unrestricted changes to dimensions, materials, components or installation arrangements. Manufacturers should therefore ensure that proposed product configurations fall within the documented field of application before making fire resistance performance claims. Extended Field of Application Where a proposed variation falls outside the direct field of application, extended application (EXAP) may provide a means of establishing a wider field of application using existing and, where necessary, additional fire resistance test evidence. BS EN 15269-1 establishes the general requirements for extended application of test results for doorsets, shutters and openable window assemblies. The other parts of the BS EN 15269 series provide specific rules for different product types and constructions. For hinged and pivoted timber doorsets, BS EN 15269-3:2022 provides rules for extending the application of fire resistance test results obtained in accordance with EN 1634-1. Annex A of BS EN 15269-3:2022 defines the construction parameter variations that may be considered. These are organised into six sections: Section A – Door leaf (Table A.2): Variations relating to the door leaf, including dimensions, construction, materials, seals and finishes. Section B – Door frame (Table A.3): Variations relating to door frame construction and its constituent materials and dimensions. Section C – Items of building hardware (Table A.4): Variations involving hinges, locks, latches, closing devices and other building hardware. Section D – Side, transom and over panels (Table A.5): Variations involving the configuration and construction of associated panels. Section E – Glazing (Table A.6): Variations involving glazing and its associated construction details. Section F – Supporting construction and attachment of door frame or side/over panels (Table A.7): Variations involving supporting constructions and attachment arrangements. Each construction parameter variation is subject to specific rules that determine whether an extension is possible using the available evidence or whether additional testing is required. The process requires evaluation by a person competent in fire resistance testing and extended application, in accordance with BS EN 15269-1 and the relevant product-specific part of the series. Not every variation will be permissible, and additional testing may be necessary. An extended application report is prepared in accordance with BS EN 15725 and the requirements of BS EN 15269-1. The results are then used to prepare a classification report in accordance with BS EN 13501-2, establishing the supported fire resistance classification and field of application. The Commercial Importance of Test Programme Design The potential benefits of extended application are greatest when manufacturers consider their intended product range before commissioning testing. A test programme developed around a single configuration may provide limited support for subsequent product variations. Where those variations fall outside the available field of application, further testing or technical evaluation may be required. Conversely, identifying the intended range of sizes, glazing arrangements, hardware and supporting constructions at the outset allows the testing strategy to be developed around those requirements. This can help manufacturers: Reduce unnecessary testing: Identify where existing evidence and applicable extended application rules can support proposed configurations. Improve market responsiveness: Establish supported product variations before they are requested by customers. Support product development: Identify the technical limitations that may influence future design decisions. Control compliance risks: Ensure declared fire resistance performance is supported by evidence applicable to the product supplied. Provide investment clarity: Establish a defined testing roadmap, allowing business leaders to understand the intended product range, anticipated expenditure and expected commercial outcomes before committing to the programme. · Improve return on investment: Direct expenditure towards commercially important product configurations rather than commissioning individual tests and only subsequently establishing their potential extended application. This approach also provides a basis for measuring the outcome of the programme against its original objectives. Once testing and classification are complete, manufacturers can establish which planned configurations are supported, identify any outstanding evidence requirements and assess the commercial value delivered by their investment. Maintaining Control of the Supported Product Range Developing appropriate evidence is only one part of demonstrating product performance. Equally important is ensuring that the evidence can be understood and applied consistently across the business. A clearly structured suite of extended application and classification reports should define the supported product configurations, permissible construction parameter variations and any applicable restrictions in a manner that is accessible to product development, sales, manufacturing and technical compliance teams. This makes it easier for commercial teams to identify and sell configurations supported by appropriate evidence, while making it more difficult for unsupported variations to be offered or manufactured without further technical review. The reports can also form the basis for product specifications, configuration controls and approval processes that prevent unauthorised substitutions or modifications. For business owners and shareholders, this provides an important additional benefit. By reducing ambiguity and strengthening control over the products being supplied, manufacturers can better manage their exposure to compliance failures, contractual disputes, remedial costs and reputational damage. Ultimately, well-defined and accessible technical evidence helps manufacturers maintain control over their product offering and reduces the risk of products being placed on the market with fire resistance claims that the available evidence does not support. Making Testing Investment Work Harder Fire resistance testing should be considered as part of a manufacturer's wider product development and evidence strategy. A successful test establishes valuable performance information. Competent evaluation, classification and the application of direct or extended application rules determine how that evidence can support other product configurations. Considering these requirements early can help manufacturers make more informed decisions about testing expenditure, product development and market opportunities. At UKTC, our Technical Services team support manufacturers in developing test programmes and evaluating the field of application of their fire resistance evidence. By establishing the intended product range and evidence requirements at the outset, manufacturers can make better use of their testing investment while maintaining confidence in the performance claims associated with their products. Developing a new doorset range or reviewing existing fire resistance evidence? Contact UKTC to discuss your testing, classification and extended application requirements. About the Author Andrew Hutchison, Operations Director Andrew Hutchison is Operations Director at UKTC, bringing extensive experience in fire testing, product certification and regulatory compliance. Holding a Master’s degree in Engineering from the University of Glasgow, Andrew has played a key role in developing UKTC’s testing capabilities and achieving UKAS accreditation. With a strong focus on improving industry standards, Andrew shares his technical knowledge and insights to help manufacturers navigate evolving regulations, demonstrate product performance and contribute to a safer built environment. Connect with Andrew

Your product has a classification of B-s1,d0. Would it still achieve that same classification when it's installed on site? Most people read a classification report the same way. Find the class, check it matches the specification, and move on. That's not the full picture, a classification only tells part of the story. Until you know how the product was tested, it may not reflect how the product is actually being used on site and that could mean a very different performance in the event of a fire. A classification has to be used alongside the field of application to identify how a product has been tested and how it can be installed and used on site. What is the Field of Application? This section of a classification report sets out exactly what your classification covers: the substrate the product was fixed to, how it was fixed, whether there was a cavity behind it, where the joints sit, and which adhesive was used, and how much. Fire tests are carried out on products as they're intended to be installed, not as they're sold. A lining fixed tight to masonry can behave very differently to the same lining on battens with a ventilated cavity behind it. That's why one product can hold several classifications. For example, a product with the classification of B-s1,d0 fixed directly to a non-combustible substrate may only achieve C-s2,d0 over a cavity. Same product, same factory, same day - a different result, because the installation has changed. When the evidence stops applying Nothing about the product itself has to change for a classification to change - the installation can change instead. If someone value-engineers the backing board or swaps in a different adhesive, the product on site can look identical to the one that was tested, while the evidence no longer covers it. Five questions worth asking about every classification report you rely on: What substrate was it tested on, and is that what your customers actually build on? Was there a cavity in the test? Is there one on site? Does the report name a specific adhesive, or a generic type? What thickness range does it cover, and are you selling outside it? If the product can be fitted either way round, were both faces tested? Scrutiny of fire test evidence has moved a long way in recent years. A classification that doesn't match the installation isn't a technicality - it's a gap in the evidence chain. Not sure your classification still matches how your product is used? Contact our Reaction to Fire Test Experts. United Kingdom Testing & Certification, A SOCOTEC company, are a UKAS accredited laboratory for reaction to fire and fire resistance testing. Its reaction to fire test suite allows manufacturers to test and prove performance with a BS EN 13501-1 classification. On average, the UKTC team issue test and classification reports within two weeks of the test.

On 2 September 2026, we reach exactly three years until references to BS 476 for fire resistance are removed from Approved Document B. From 2 September 2029, manufacturers, specifiers and building control bodies in England will no longer be able to rely on Approved Document B's references to BS 476 fire resistance testing. Three years can sound like plenty of time. In practice, transitioning a product’s fire performance evidence from BS 476 to the EN testing and classification system is rarely a quick job. It's worth understanding now what that transition actually involves - and why the manufacturers who start planning early will be in a stronger position than those who leave it late. What's Actually Changing Approved Document B currently allows fire resistance to be demonstrated using either the British Standard (BS 476) test methods or the European (BS EN) equivalents. From September 2029, the BS 476 route is removed from the guidance. Products will need fire resistance evidence based on the EN testing and classification system, principally to BS EN 13501-2, supported by testing to the relevant BS EN test standards. This doesn't mean every BS 476 report becomes worthless overnight, or that every product needs retesting immediately. It means that, from that date, BS 476 evidence will no longer be recognised as a route to compliance under Approved Document B guidance for new specifications. Why Three Years Isn't as Long as It Looks A transition programme for a single product range can involve several distinct stages: Evidence review – establishing exactly which products, configurations and applications currently rely on BS 476 test data. Gap analysis – identifying where existing EN evidence already exists, where it's partial, and where none exists at all. New testing or assessment – scheduling fire resistance tests where necessary and using Extended Field of Application (EXAP) reports to extend the scope of existing EN test evidence. Certification updates – updating third-party certification schedules and technical documentation to reflect the new evidence base. Each of these stages takes time, and they don't always run in a straight line. A test result that falls short of expectations can send a product back to development before retesting is possible. Factor in enough of those cycles and a three-year window starts to look considerably shorter. Testing Capacity Is Worth Thinking About Now As the deadline approaches, it's realistic to expect testing laboratories to see increased demand from manufacturers all working towards the same date. Booking slots, sample preparation and furnace availability all become harder to secure the closer you get to 2029. Manufacturers who plan their testing programmes early are more likely to secure the dates that suit their production and commercial timelines, rather than working around whatever capacity remains. Prioritising Where It Matters Not every product needs attention at once. A practical starting point is to prioritise based on: Commercial importance – which products or ranges generate the most volume or margin. Current specification activity – products actively being specified into live projects should take priority over those with limited ongoing demand. Evidence gaps – products with no EN evidence at all versus those where an EXAP could extend existing test data relatively quickly. This kind of triage means resources go where they can have the greatest impact, rather than treating the whole portfolio as equally urgent. What Manufacturers Should Do in 2026 Your priority should be to understand where you are in the transition cycle: Which products still depend solely on BS 476 evidence? Where does EN evidence already exist, and does it cover the full scope you need? Starting this work now, rather than in 2028 or 2029, means testing costs can be spread over a longer period, laboratory slots can be booked with more flexibility, and technical decisions can be made without the pressure of an approaching deadline. How UKTC Can Help UKTC works with manufacturers of passive fire protection and construction products to plan exactly this kind of transition. That includes fire resistance testing to current EN standards, review of existing test evidence, scoping analysis to identify gaps and opportunities for test programme planning, classification reports and EXAP development. If you want to understand where your product range stands against the 2029 deadline, speak to UKTC. We can review your existing evidence, identify gaps and help you build a structured testing and transition programme.

UKTC's new fire resistance laboratory offering testing of specimens 3 meters wide and up to 5 meters tall will be opening in the summer of 2026. A New Fire Resistance Laboratory. Built for you. Combination Furnace As part of a £2.5 million investment, UKTC can now offer both vertical and horizontal fire testing from its UK based laboratory. The expanded fire resistance service includes one of the UK’s only combination furnaces, allowing manufacturers flexibility to test in either a: 3 x 3m Vertical Furnace Configuration 3 x 4m Vertical Furnace Configuration 3 x 5m Vertical Furnace Configuration 3 x 4m Horizontal Furnace Configuration Additional Test Methods As part of the expanded service offering, new test methods will be available for manufacturers at UKTC to utilise the new fire resistance furnace. These include: Walls & Partitions (up to 5 meters) BS EN 1364-1:2015 Floors (Load-bearing) BS EN 1365-2:2014 Steel Protection / Encasement BS EN 13381-4:2013 Floors (Non Load-bearing) BS EN 1364-2:2018 Doorset Hardware - methods C & D BS EN 1634-2:2008 Enquire Now "There is growing demand for a new laboratory in the UK. This investment will directly contribute to a safer built environment; generating greater availability for the construction market." Andrew Hutchison, Operations Director, UKTC Request a Quote Be amongst the first to test in our new fire resistance laboratory by enquiring below. We aim to respond to your enquiry within 1 working day Button Testing Reaction to Fire Button Technical Classification Reports Button Certification UKTC ensure™ Button Testing Doorsets & Hardware Button Technical EXAP Reports Button Testing Walls & Partitions

United Kingdom Testing and Certification - UKTC - offer market leading fire testing and certification services to demonstrate client’s building materials and components comply with all appropriate standards and building codes. Accredited by UKAS. FIRE TESTING & CERTIFICATION SERVICES FOR CONSTRUCTION PRODUCTS & BUILDING MATERIALS We are United Kingdom Testing & Certification, a UKAS accredited provider of fire testing and certification services for construction, building and passive fire product manufacturers across the UK. We test, inspect and certify to ensure products are safe, quality and compliant. Testing Certification Technical UKAS ACCREDITED FIRE TESTING AND CERTIFICATION SERVICES. United Kingdom Testing and Certification (UKTC) deliver fire testing and certification services that enable manufacturers of building materials and products to demonstrate compliance with all appropriate international standards, regulatory obligations and customer expectations. Testing Services Button Technical Services Button Certification Services Button Committed to Quality and Competence. UKTC is a UKAS accredited testing laboratory No. 21542. The laboratory is accredited by UKAS to ISO/IEC 17025:2017 for Resistance to Fire Testing of the non-load bearing elements of construction including; door and shutter assemblies, walls and partitions, linear joint seals, glazing and architectural hardware. Learn More Testing Reaction to Fire Button Technical Classification Reports Button Certification UKTC ensure™ Button Testing Doorsets & Hardware Button Technical EXAP Reports Button Testing Walls & Partitions Button Our customer experiences The lab install team went above and beyond to get the sample ready for the test (nothing was too much trouble). Thanks to Barry & Thomas and all the team for their effort. Really is appreciated. Integrated Doorset Solutions Ltd. Always a pleasure to deal with the team at UKTC Hampton Doors Very insightful visit. Extremely good company to work with and always flexible to accommodate your requirements. Obex Protection Ltd. Great service and support from the team throughout. Merit Holdings Brilliant Team. Very family feel in the company. Intelligent Membranes Excellent test facility and all of the engineers were very knowledgeable and experienced. Very happy overall and we will be back soon! Jeld-Wen A massive thank you to Rob and the team for all their efforts in what was another successful result for us. Specialist Door Solutions Ltd. Excellent experience with knowledgeable and helpful staff. Good organisation and brilliant hospitality. Westport

Explore exciting career opportunities at United Kingdom Testing and Certification. Speak to our team today and find out the open job Opportunities that we have. Career Opportunities As part of our team, you're joining ambitious colleagues, intent on acting with integrity to find solutions to global challenges. We are proud of the diversity of our team and our collaborative approach to working supports our inclusive environment, encouraging individuals to contribute their whole self to working with us, for the benefit of the public and industries around the world. Join a Team Driving Change. We enable our people to take on new challenges, in varied and interesting roles, that contribute to making the built environment safer. Work at UKTC is interesting, innovative and incredibly valuable. You’ll have the opportunity to keep developing your knowledge and skills to continue your professional development throughout your career with us. Current Job Openings Technical Officer Full Time View Job View Job