Multi‑storey residential buildings - fire risk posed by external wall systems: consultation analysis

An independent analysis of consultation responses to the Draft Scottish Advice Note (SAN): Determining the fire risk posed by external wall systems in existing multi-storey residential buildings.

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6. Aluminium Composite Material with Unmodified Polyethylene Filler

Question 4. Does the advice clearly explain the risk posed by Category 3 Aluminium Composite Material (ACM) with an unmodified polyethylene filler, and what actions building owners should take if their buildings have these systems?

Overview of Responses

Table 13: Does the advice clearly explain the risk posed by Category 3 ACM with an unmodified polyethylene filler, and what actions building owners should take if their buildings have these systems?
  Yes No
  Number % Number %
Individual 7 88% 1 13%
Organisation 11 69% 5 31%
Fire Safety / Engineering / Consultants 3 75% 1 25%
Misc Construction 1 33% 2 67%
Finance and Insurance 2 67% 1 33%
Housing and Property Management 1 50% 1 50%
Local Government 2 100% 0 0%
Residents and Tenants Groups 1 100% 0 0%
Further and Higher Education 1 100% 0 0%
Total 18 75% 6 25%

N=24. Percentages do not add up to 100 due to rounding.

6.1 A vast majority of consultation respondents reported that the advice clearly explained the risk posed by Category 3 ACM with an unmodified polyethylene filler, and what actions building owners should take if their buildings have these systems (18, 75%), Table 13. Individuals were more likely to report this than organisations.

6.2 Among those who noted that the risk posed and action to be taken were clear, half provided further comment.

6.3 Firstly, a few respondents provided follow-on comments that reiterated or substantiated the "yes" response to the closed question e.g. "the recommended course of action for building owners is well set out and easy to understand both in terms of the reason for the requirement and the appropriate actions to be taken" (Individual), "yes reasonably so" (USHA) Fire (Scotland) Group).

6.4 Some questioned elements of the advice as it is currently presented in the Draft SAN, as they thought it was ambiguous or lacked clarity, or thought there were too many caveats provided - as reflected in the respondent quotes below.

"Does the wording of "it is strongly recommended" go far enough where extensively clad?"

Scottish Fire and Rescue Service

"The strong recommendation that extensively clad Category 3 MCM external wall systems should be removed without delay is clear…. it is unclear what action can be taken, or by whom, to ensure this happens in circumstances where the building owner chooses not to follow the advice. This should be clarified".

National Fire Chiefs Council

6.5 Another respondent questioned the emphasis placed on Category 3 ACM cladding in a Scottish context given its limited use.

"It is my understanding that there are only two buildings located at Glasgow Harbour that have extensive use of this material and a solution to remedy it is in hand. There are another 22 known cases where this material is partially used in buildings which is a small and manageable number".


6.6 One-quarter of respondents (primarily organisations) suggested that the advice did not clearly explain the risk posed by Category 3 ACM with an unmodified polyethylene filler, and what actions building owners should take if their buildings have these systems, Table 13.

6.7 While a few of these respondents noted in their qualitative feedback that the guidance gives clear advice on the levels of risk posed or that such cladding systems should be removed without delay (e.g. ARUP, Building Societies Association), they typically went on to raise wider points that they considered needed to be clarified within the Draft SAN.

6.8 Firstly, as noted above in Section 6.4, a couple of other respondents agreed with the SFRS view that the wording in the Draft SAN was not strong enough. However, Rockwool Ltd and MIMA both went further to note broader aspects of concern. These points are reflected in the respondent quote on the next page.

"The Scottish Government must go further than "strongly recommending" any extensively clad external wall system incorporating ACM PE should be removed from all residential buildings without delay. This material must urgently be identified and removed from all high-rise and other high-risk buildings in Scotland. We are also very concerned that the advice note, while highlighting the dangers of ACM (PE), appears to suggest that certain combustible ACM systems which are not permitted under the UK Government's remedial funds may be a solution for buildings in need or remedial works in Scotland. The narrow focus on ACM in Scotland has also meant that many other types of combustible materials and combinations have been overlooked or their risks downplayed".

Rockwool Ltd

6.9 Rockwell Ltd and MIMA also expressed strong concern about reference within the Draft SAN to, and the outcome of, the UK Government test and analysis report "Fire performance of cladding materials research" that investigated the behaviour of selected non-ACM cladding products, and called for it to be removed from the advice note. The comments noted a number of specific issues with that research, including the bespoke testing system that was used. The following quote is reflective of the points raised.

"…this research uses a bespoke testing system that is considered to have a number of inadequacies and should not be used as a foundation for statements about the 'unique' dangers of ACM (PE). The Government had to create a new, unofficial test method for non-ACM cladding to provide an indication of its fire performance (as it did not have BS 8414 tests for all the different kinds and combinations of combustible cladding and insulation). This test method has a number of inadequacies:

  • The test does not incorporate combustible insulation, which when present makes combustible cladding burn much quicker;
  • The test has no success or failure criteria to measure how a material has performed; and
  • The test has no legal basis to ensure the removal of non-ACM cladding from buildings, bringing further uncertainty to building owners.

References to this report should be removed from the advice note as these tests are inadequate and underestimate the risks of combustible materials on high-rise and other high-risk buildings. The advice note should use the clearest system - Euroclass system – rating each product to determine their combustibility and are safe to use on buildings".


6.10 Wider individual points raised include the following:

  • ARUP felt that the guidance did not sufficiently explain the different levels of risk posed by different categories of ACM – "it just defines them and states their calorific value".
  • An Individual respondent raised concern with the current shortage of fire safety engineers; and
  • Building Societies Association noted that the guidance was clear in some sections regarding risk/actions and less so in others - "it is clearly recommended in Section 2.2 of the Draft San that ACM-3 and other MCM should be removed from all buildings. Section 2.5 is less clear and allows a degree of subjectivity".



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