As readers of our previous articles will be aware, one of the consequences of the devastating Grenfell Tower fire tragedy is the ongoing uncertainty for those living in multi-storey, multi-occupancy residential buildings.   Those uncertainties begin with the question of the extent to which remedial work might be required to make an external wall construction of a building safe; and the methodology that ought to be used in assessing safety issues in such buildings.

The Ministry of Housing, Communities and Local Government (MHCLG) Consolidated Advice Note, issued in January 2020, gave advice to building owners of multi-storey, multi occupancy residential buildings (both above and below 18 metres in height) and its recommendation was that building owners sought professional advice on what further steps should be taken with respect to cladding systems covering such buildings.   Those systems could include external wall insulation systems with render or brick slip finish; external wall systems with cladding other than ACM; external wall systems with ACM cladding; balconies; partial ACM cladding; spandrel panels; and HPL.

However, the assessment of fire risk in such a wide range of buildings has proved problematic in practice.   These problems have largely arisen because of a lack of information on the fire performance of materials and systems used on buildings; and the relative lack of qualified professionals with the necessary skills and experience to carry out meaningful Fire Risk Appraisals and Assessments (FRAA’s).  These difficulties have led to inconsistent outcomes following inspections, including inconsistent recommendations for buildings that ostensibly contain similar or identical risk factors.

These problems have led to the identification of a need for specific guidance relating to the conduct of FRAAs of external wall constructions of multi-storey, multi-occupancy residential buildings.  Into that breach is stepping the British Standards Institution (BSI), the UK’s national standards body.   It is consulting, until 20 May 2021, on a draft Publicly Available Specification (PAS), called PAS9980 – Fire Risk Appraisal and Assessment of External Wall Construction and Cladding of Existing Blocks of Flats – Code of Practice.

PAS9980 is designed to supplement an existing PAS, PAS79-2, which is suitable for buildings where it is manifestly obvious that the fire risks associated with an external wall construction are low (e.g. traditional masonry construction buildings; and buildings pre-dating the mid-1960’s).

The draft PAS9980 contains recommendations and guidance tailored to the particular risks posed by fire spread over external walls; and provides tools for a competent person to carry out an FRAA of an external wall construction.  An FRAA, properly completed, is intended to inform the Fire Risk Assessment, completed in accordance with Article 9 of the Regulatory Reform (Fire Safety Order) 2005 (as amended).  It is therefore a key part of assessing what, if any, remedial works might be required to a multi-storey, multi-occupancy residential building to address cladding concerns.

What is perhaps most interesting about the PAS9980 consultation is the direction of travel which it perhaps points to.  The draft PAS9980 recognises that any FRAA will inevitably be, to a large degree, subjective because definitive fire performance of an actual external wall build up can only be determined by a large-scale test.  The methodology therefore adopted in PAS9980 assumes that a risk-based approach is acceptable to all relevant interested parties, rather than an approach which judges existing buildings against strict compliance with guidance in the current version of Approved Document B (which is likely to contain significantly stricter rules than may have existed at the time the building was constructed).

The BSI’s justification for adopting this approach is that, despite numerous historical fires involving external spread of fire from one apartment to other apartments within a block (many of which are listed in PAS9980), it is only the Grenfell Fire that resulted in any loss of life beyond occupants in the apartment where the fire began.  Additionally, the document notes that in the year 2019/20, of 7,500 fires in purpose-built blocks of flats in England, only 16 (0.2%) resulted in the need to evacuate more than 5 people.   Thankfully, fires of the magnitude of that at Grenfell Tower are extremely rare.

Against that background, PAS9980 aims to assist in making comparisons and assessing the relative risks of different types of materials, components, systems and configurations of external wall constructions.  As the PAS says, the determination of absolute levels of safety are simply not possible at the time of publication of this document, because insufficient real-life data is available.  Accordingly, the stated aims of PAS9980 include:-

  • To provide fire engineers with a standard methodology for appraising and assessing the scope for, and risk from, fire spread via external wall construction and cladding, such that the outcome can be used to inform a building’s fire risk assessment;
  • To enable recipients of an FRAA to understand the process and methodology applied and to interpret the findings;
  • To assist non specialists reviewing an FRAA to understand the risk of external fire spread in the context of a building’s overall fire strategy and fire safety arrangements;
  • To enable common relevant terminology to be adopted by all who carry out FRAAs and to promote consistency in them and a pragmatic and risk-proportionate approach to them;
  • To enable consistent training in carrying out FRAAs and thus facilitate more entrants into the profession; and
  • To satisfy professional indemnity insurers that there is a national standard underpinning consistency in the carrying out of FRAAs.

Much of what is contained in the draft PAS9980 is technical fire safety advice and guidance, beyond the scope of this article.  Anyone with relevant experience in that field is recommended to log onto the BSI website and take part in the consultation, which is open until 20 May 2021.

For the rest of us, the BSI’s involvement in this important area is to be welcomed and it is to be hoped that the BSI’s involvement in this important area will promote a proportionate and consistent approach amongst building owners, leaseholders and insurers, such that everybody involved in this difficult area is provided with a considerably greater degree of certainty than currently exists.

Following the consultation, the BSI’s aim is to publish the final version of PAS9980 in September 2021.