It is not the first time we have discussed it on the programme. In truth, we have spoken about PAS 9980 on several occasions. Yet it is one of those topics that simply cannot be allowed to drift away, because the consequences of getting it wrong reach directly into the safety of people living in residential buildings.
PAS 9980 has become an influential document in the post-Grenfell landscape. It provides a methodology for assessing fire risk in external wall systems on existing blocks of flats. In practice, it is often used to guide decisions about remediation, mitigation, and whether combustible materials need to be removed.
Originally it was intended as guidance. Over time it has started to carry far greater weight.
The debate now gathering pace across the sector is whether PAS 9980 could or should become embedded in legislation. That possibility raises a serious question. Would giving the document statutory force in its current form strengthen safety, or could it introduce new risks?
PAS 9980 works by guiding professional judgement. An assessor considers construction materials, fire spread potential, building height, occupancy profile and mitigation measures before forming an overall view of risk.
As a technical methodology, that approach has merit. External wall systems are complicated, and rigid rules can sometimes lead to unnecessary or poorly targeted remediation.
The difficulty arises with the concept of “tolerability”.
Under PAS 9980, combustible materials may remain in place if the assessor concludes that the overall risk is tolerable once mitigation measures are taken into account. That might include cavity barriers, alarm systems, sprinklers or evacuation procedures.
On paper that reflects a balanced engineering judgement.
In reality it introduces a degree of subjectivity.
Two competent assessors applying PAS 9980 to the same building may reach different conclusions. One may recommend remediation while another concludes that the risk can be managed. Both decisions could be justified within the same methodology.
That level of variation becomes far more serious if the framework is embedded in law.
Legislation governing life safety normally aims to reduce uncertainty. It sets clear duties, clearer thresholds and enforceable outcomes. Guidance, by contrast, allows room for interpretation and professional discretion.
PAS 9980 still carries the character of guidance rather than legislation.
Competency illustrates the issue. The document acknowledges that external wall fire appraisals require specialist expertise. Not every fire risk assessor is qualified to undertake them.
Yet it does not establish a single legally binding competency standard or a fully unified accreditation framework for those carrying out assessments.
If a system relies heavily on professional judgement, the rules around who can exercise that judgement need to be exceptionally robust. At present, that framework remains uneven.
Another concern raised by critics relates to the broader culture that a tolerability model can create.
A hazard-focused system asks why dangerous materials remain on a building. A tolerability-based system asks whether the risk can be justified as acceptable.
That difference matters greatly in a post-Grenfell environment where public confidence depends on visible reduction of risk rather than reassurance built on interpretation.
This week on Cladding Matters, Gareth Wax chairs the discussion alongside myself, Hamish McLay, and Stephen Day of Royal Artillery Quays, who continues to bring the lived experience of residents navigating the realities of building safety decisions.
We will also be joined by Florentina Punga, whose recent analysis explores the risks of elevating PAS 9980 from technical guidance into legislation without first strengthening competency rules, evidential thresholds and removal triggers.
It will be interesting to hear her perspective on where PAS 9980 should sit within the wider Building Safety Act framework and whether a legislative version could ever provide the clarity that life safety law demands.
Because ultimately this debate goes beyond one document.
It goes to the heart of what the United Kingdom expects from its building safety system after Grenfell. PAS 9980 may still have an important role as guidance.
Whether it should become the law that determines when dangerous materials remain on people’s homes is another matter entirely.
Cladding Matters airs this Friday at the slightly later time of 2pm.
Watch live or catch the replay on YouTube:
https://www.youtube.com/@SpillingTheProper-Tea
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