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EXAP: The Value of Extended Field of Application Reports in Fire Safety Testing.

Extended Application reports, or EXAPs, have become increasingly important in the evolving landscape of fire safety. These reports present a prediction of performance based on one or more test results, thereby enabling a broader field of application while maintaining or enhancing performance. In this article, we explore the purpose, process, and benefits of EXAP in ensuring fire safety.

A worker looking at a fire door with wires coming off it

Understanding EXAP

EXAP is an abbreviation for Extended Field of Application. It is an exception in BS EN fire resistance test standards that permits a broader range of approved applications beyond what was tested in the relevant fire test standard. The EXAP reports generated by United Kingdom Testing and Certification cover fire resistance and smoke control for doors, shutters, and openable window assemblies under the BS EN 15269 series.

The Need for EXAP

EXAP has become increasingly critical in the wake of the Hackitt Report of 2018, which triggered changes to Approved Document B. These changes require that products and systems for fire resistance are tested against BS EN standards, and only extended (EXAP) or direct (DIAP) application rules can be used to extend results. Furthermore, official BS EN 13501-2 classifications should be provided, with all tasks conducted by Approved Bodies.

The strict extension rules in an EXAP standard mean that stringent criteria must be met to apply variations to the product, such as increases in size or the use of alternative components.

How is EXAP Testing Carried Out?

Testing for EXAP adheres to a simple, four-step procedure:

1. Scope Analysis: A scoping exercise is undertaken which reverse engineers a test programme from the desired field of application.

2. Test: Testing must use the appropriate BS EN fire-testing standard.

3. Extend: Test data can be extended to similar applications, but only by a qualified Approved body using the test standard (DIAP) or extended application standard (EXAP). Importantly, this is only permitted where the standards explicitly allow it.

4. Classify: This evidence must be validated and summarised in an official third-party classification report.

EXAP and the 'Golden Thread'

Upcoming building-safety regulations will soon require a 'golden thread' of building-performance evidence, particularly around fire safety. This calls for an up-to-date, easily accessible, and unbroken thread of information. BS EN and EXAP evidence ensures that fire-safety information is robust, clear, and consistent, facilitating the achievement of the golden thread across the industry.

How EXAP Enhances Confidence in Design and Construction

EXAPs are an invaluable tool for designers and contractors concerned about liability for poor design and construction, issues with securing insurance, and extended defect liability periods. Compliance with Approved Document B via EXAP testing is a reliable way to mitigate these risks.


EXAP, or Extended Field of Application reports, are crucial to modern fire safety testing. With their ability to predict performance and extend application scopes, they streamline compliance with fire safety regulations and contribute significantly to the 'golden thread' of building performance evidence. Whether you're a designer, contractor, or a regulatory body, understanding and implementing EXAPs can significantly enhance your fire safety measures and build confidence in your design and construction practices.

How UKTC can help in your testing needs

At United Kingdom Testing and Certification, we are committed to helping you navigate the complexities of fire safety testing and compliance. With our expertise in EXAP reports and a suite of testing services under BS EN 15269-1, we ensure you meet the stringent requirements of Approved Document B. Contact us today for a consultation, and let's work together to make your building safer and more resilient.

Are you looking to find out more information? Contact us at or call us on 01355 433122; our experienced team will be happy to help.


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