In this article, Rose Wilson and Mariya Rankin from Eversheds Sutherland (International) LLP, and Bhavina Vasishta from Rimkus consider whether the role of expert witnesses in building safety disputes requires an urgent rethink following Grenfell and the sweeping reforms of the Building Safety Act 2022.
Introduction
The construction industry stands at a crossroads. Following Grenfell and the sweeping reforms of the Building Safety Act 2022 (“BSA”), the role of expert witnesses in construction disputes has never been more critical—or more contested. As construction lawyers and technical experts, it is apparent we must rethink how experts are engaged —not only to resolve disputes, but also to deliver safe, compliant buildings and restore public trust.
Expert Evidence: A New Battleground
With over 17,000 buildings reported as potentially unsafe and nearly 2,000 still awaiting fire safety remediation, the scale of the challenge is vast. The government’s Remediation Acceleration Plan sets a hard deadline—2029—for completion of works on high-rise buildings, with penalties for non-compliance. Coupled with a 30-year limitation period for claims under the Defective Premises Act, disputes are on the rise.
Expert witnesses—often architects or fire safety engineers—are central to these disputes. Their evidence is crucial not only for assigning liability but also for ensuring remediation proposals meet current building regulations. The expectations placed on experts have never been higher.
A Role Under Pressure
Traditionally, expert witnesses provide independent, evidence-based opinions on technical matters. Today, however, they are asked to do far more, often retrospectively and with limited documentation. Their tasks include:
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Assessing the as-built construction and fire performance of cladding systems.
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Evaluating fire-stopping, fire doors, smoke control, and implementation of fire strategies.
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Identifying breaches of building regulations and guidance from the time of construction to the present.
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Determining whether statutory duty holders met their obligations as amended by the BSA, whether under the Regulatory Reform (Fire Safety) Order 2005 for occupation or the Building Regulations 2010 for design and construction.
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Advising on remedial measures that satisfy current building regulations and withstand future scrutiny.
This is not just a technical challenge—in many ways it is a professional minefield. The line between expert witness and design consultant is blurring, raising questions about impartiality, professional indemnity, and the purpose of expert evidence.
Impartiality at Risk?
One recent shift is the earlier engagement of experts—often before formal proceedings. While early involvement is valuable and can proactively manage risk, it may compromise impartiality. For example, if an expert engaged to design a scope of remedial works is subsequently instructed to give evidence independently, which may include an assessment of a remediation design they played a role in.
To preserve credibility, it is important that experts:
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Are appropriately qualified and experienced in the relevant discipline.
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Clearly define the limits of their expertise and avoid advising beyond it.
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Maintain transparency about the limitations of available evidence, especially in historical assessments.
The BSA has ushered in a more proactive regulatory environment, but it has also created uncertainty. How far should experts go in offering hindsight assessments? What level of detail is appropriate when advising on remediation, without encroaching on the role of the designer.
Professional Obligations
Experts must also navigate their own professional codes of conduct. For example, architects are bound by the Architects Registration Board’s code, which prioritises public safety and the health of building users. These obligations must be balanced with their role in legal proceedings and technical assessments.
Conclusion: Call for Clarity and Collaboration
If we are serious about building safety, we need a new approach to expert evidence. As the industry continues to adapt to the post-Grenfell regulatory environment, the expectations placed on experts will only grow.
Lawyers, insurers, and regulators must work with experts to define clear boundaries, support impartiality, and ensure expert evidence contributes meaningfully to the safe and timely remediation of high-risk buildings via approaches that balance independence with practical and cost-effective problem-solving.
The ability to deliver safe, compliant buildings—and resolve disputes fairly—depends on getting this right and putting expert evidence back at the heart of building safety. Expanding the expert’s role in addressing unsafe buildings is perhaps the next step towards ensuring these buildings are efficiently and effectively remediated.