Navigating Design Complexity: How KFS Supports Modern Fire Door Designs with Evidence Based Technical Assessments
The Challenge of Bespoke Designs
Bespoke fire door designs can need more than just test evidence
Fire door requirements on modern projects often involve bespoke aspects such as Jib door designs (concealed frames), wall and door decorative cladding, recessed grooves, recessed panels, ironmongery, door leaf modifications, unique leaf face finishes and glass and glazing systems requirements that fall outside of the tested configurations and/or Field of Application Reports.
As seen in the Berkeley Square project, manufacturers like Forza Doors must balance design ambition with clear evidence of fire resistance performance, even when available test data does not fully represent these bespoke solutions.
A Technical Assessment bridges this gap by taking available evidence, interpreting how the variations may affect performance and applying data driven engineering principles where direct evidence is limited to ensure that the required performance is achieved. This gives manufacturers a structured, defensible route to compliance of complex door designs.
Changing Expectations
An evolving industry and standards are reshaping expectations in 2026
The fire safety landscape continues to evolve. BS 8214:2026, the updated Code of Practice for Fire and Escape Doors, has a wider scope than before and addresses responsibilities of various stakeholders. Further, the ASFP will soon publish their Green Book Volume 1 (Fire Door Systems). Together with a changing approach post-Grenfell, evidence-based documentation is more important than ever in order to demonstrate the fire resistance of bespoke doors.
““Compliance has always been a fundamental requirement in the UK, but as the industry continues to evolve, both its importance - and the ability to clearly demonstrate it - are being recognised more than ever.”
Expertise Through Collaboration
A collaborative approach to complex door design
Manufacturers designing bespoke fire resisting door assemblies increasingly face challenges that sit outside standard test configurations typically tested. Non-standard aspects driven by project requirements can push designs beyond what has already been proven or what would be commercially viable for testing. Kiwa Fire Safety Compliance (KFS) supports manufacturers through this complexity by delivering evidence based technical assessments that help project teams make clear, informed decisions aligned with current standards and recognised engineering principles.
This blended approach of practical support for bespoke design combined with rigorous technical scrutiny, has recently been demonstrated through KFS’s work with Forza Doors on a high-spec office development.
Applying Technical Expertise
A robust technical assessment for a high-spec project
Forza Doors commissioned KFS to carry out a Technical Assessment of bespoke timber doors for a premium development at Berkeley Square, Mayfair.
The Product Evaluation Team reviewed drawings, specifications and supporting evidence to assess the proposed construction against fire performance requirements, applying engineering principles where direct test data was unavailable. Carrying out this review promptly allowed areas that needed further attention or additional test evidence to be addressed early within the project.
The Technical Assessment also considered the newly updated BS 8214:2026 - released only weeks earlier - ensuring the work reflected the most current guidance on fire resisting and smoke control door assemblies. By adopting the latest version of the standard, the assessment aligned with up-to-date approaches and expectations.
The resulting Technical Assessment Report provided Forza Doors with clear boundaries for an approved design, an understanding of acceptable variations and a clear record of the technical approval, allowing their project teams to progress confidently while maintaining compliance.
The assessment process was conducted in line with the 2021 PFPF ‘Guide to Undertaking Technical Assessments of Fire Performance of Construction Products Based on Fire Test Evidence’, which is cited in Approved Document B and is the established industry procedure for such work.
How a KFS Technical Assessment works
Every Technical Assessment follows a structured approach. While each project is tailored to its specific door design, the process typically includes:
Review of client submissions
Including drawings, specifications, construction details, and any supporting fire test evidence reports.
Identification of tested and untested elements
Evaluation of the proposed door assembly to determine which components fall within the scope of existing fire test evidence and which represent variations. This may include door sizes, hardware, glazing arrangements, seals, frame configurations, and other assembly details.
Assessment of variations
Variations are substantiated using relevant test evidence and established fire engineering principles , supplemented where necessary by our team’s extensive experience. In some cases, additional supporting evidence may be requested.
Provision of design guidance
Defining acceptable design parameters, recommended detailing, and any limitations required to support the assessed fire performance of the proposed assemblies.
Delivery of a detailed, auditable report
Issuing a comprehensive Technical Assessment report that clearly documents the methodology, evidence considered, conclusions reached, and any conditions or limitations. The report provides clarity and confidence for all stakeholders, including manufacturers, installers, specifiers, and regulatory authorities.
Ongoing Advice Agreements
In addition to individual Technical Assessments, Ongoing Advice Agreements are available to support projects from the early design stages. These arrangements allow our Technical Specialists to review proposals and provide guidance throughout the design and development process, helping to identify potential compliance issues early and supporting smoother project progression through to final assessment.
Benefits for manufacturers and design teams
This combined approach offers several valuable outcomes for clients working with complex or bespoke fire door systems:
Clarity around design boundaries
Confidence in compliance decisions
Defensible approvals
Responsive project support
Reduced project risk
“Their (KFS) technical expertise, professionalism and structured approach ensured the project progressed smoothly while maintaining compliance.”
Evidence in Practice
Forza Doors highlighted that the Berkeley Square project included non-standard designs. The assemblies featured enhanced leaf thicknesses, automatic door operators with additional concealed electric locks, rebated leaf edges, and custom frames, with plasterboard finishes seamlessly integrated into leaf and frame interfaces that challenged typical compliance routes. They described KFS’s approach as methodical, practical and grounded in evidence, noting the clear communication of design boundaries and limitations.
KFS’s structured and collaborative approach, including their adherence to agreed timelines and adaptability when project needs changed, was central to ensuring the project progressed smoothly.
Jim White, Technical Director, Forza Doors:
"The Berkeley Square project included complex fire-rated door designs that challenged typical compliance routes. Kiwa Fire Safety provided clear, practical guidance, helping us understand design boundaries, manage risk and make informed decisions throughout the project. Their technical expertise, professionalism and structured approach ensured the project progressed smoothly while maintaining compliance."
Chris Marriner, Director of Product Evaluation, Kiwa Fire Safety Compliance:
“Compliance has always been a fundamental requirement in the UK, but as the industry continues to evolve, both its importance - and the ability to clearly demonstrate it - are being recognised more than ever.
At KFS, we take pride in supporting our clients by delivering robust Technical Assessments, providing clear documentation to support the fire resistance performance of their products and offering a clear and effective way of demonstrating compliance. We have a highly capable, client focused technical team that works with integrity, and the recognition from Forza reflects their commitment to delivering work to the highest standards.”
Interested to find out more?
If you’re working on fire resisting door assemblies or wider passive fire protection products that sit beyond typical tested configurations, a Technical Assessment can provide the clarity needed to progress with confidence.
Through our Technical Assessment, On-going advice and Field of Application services KFS help our clients to understand the limits, manage risk and align with current industry expectations.
Learn more via the links below:
KFS Client: Forza Doors
Learn more about Forza Doors, the specialist manufacturer behind the project featured in this article.
The company specialises in high-performance timber fire doorsets, screens and specialist joinery solutions for demanding commercial and residential projects.
