Frances Maria Peacock MCIAT, IHBC, MIFireE, MSFPE, PG Cert., BSc, Dip. HE

‘Advice for Building Owners of multi-storey, multi-occupied residential buildings’

It may be the case that two high-rise buildings are covered in the same type of ACM cladding, but one poses a greater risk than the other simply due to its shape, form and features.

Frances Maria Peacock

The governments release of the advisory document for building owners this month, seemingly to update and consolidate previous advisory notes, is a mixture of positives and negatives.  It is encouraging that some of the fundamental issues regarding building safety have been acknowledged, but at the same time doubts remain over funding and the overall will for those with responsibility to act.  As 2020 begins, thousands of people remain trapped in unsafe buildings, facing financial ruin alongside the unimaginable fear of a repeat of the Grenfell disaster which claimed 72 lives.

The need to “assess and manage the risk of external fire spread applies to buildings of any height” is emphasised within the document.  This is something I have long recognised due to the amount of combustible materials being used throughout the construction industry in many types of building, from low-rise domestic housing to high-rise flats.  Many of these buildings – whether high or low rise – are beset with a range of structural defects including inadequate fire stopping.  Some of the construction methods being employed can also be questioned for their integrity and ability to withstand fire, and one only needs to consider recent incidents involving timber framed buildings to realise that the risk goes beyond high-rise blocks with combustible facades.

The document also states that “building owners and the wider construction industry need to respond more urgently to the safety issues being clearly identified,” and that the “safety of residents should always be an urgent concern.” It is good that this has been acknowledged, but such statements will consist of hollow words if it not followed by action.  In the meantime thousands remain in unsafe homes due to a lack of funding to replace flammable cladding and address other defects which compromise fire safety in buildings.  There is no mention of where the funding will come from, and therefore nothing to stop the deplorable tendency for building owners to attempt to pass this cost to residents.

Paragraph 1.15 in the document refers to the industry as “not acting with due haste” to remove Category 3 – the most dangerous type of cladding – which includes aluminium composite (ACM) panels with unmodified, and therefore combustible, cores.  At the beginning of January it was reported that 315 high-rise buildings still had ACM panels in place, which amounts to 71% of the total.  This is indicative of the slow progress and shows that there is still a long way to go.

The question is, how does the Government propose to speed things up?  The document is keen to advise building owners on how to identify the type of cladding on their building and assess the risk, as well as suggest what interim measures should be taken until it can be removed.  It also states that owners should not rely on interim measures long-term.  The advice appears sound, but there is nothing to compel building owners to take action.

Apart from the need to remove combustible cladding, there are other pressing safety issues which the document does not deal with.  For example the construction industry needs a thorough shake up and an end must be brought to the culture of profits before quality and safety.  The huge number of new homes, ranging from blocks of flats to bungalows, with dangerous defects is a cause for concern.  The tendency to erect buildings as quickly and cheaply as possible so that they can maximise the developer’s profits has got to end.  Greater control of quality is therefore an urgent requirement.

When defects are identified, they should be rectified at the earliest opportunity and not ignored.  The document goes through a list of things a building owner should check when assessing the risks, but it does not suggest rectification of the problems should identified.  If for instance there are gaps around services which penetrate a compartment wall, the advice is for this to be taken into account in the risk assessment, but nowhere does it say that the owner should take steps to fix it.

More needs to be done to identify other less obvious uses of flammable materials, as well as construction methods which have been shown to pose a risk.  In August 2019, Beechmere care home in Crewe was burnt to the ground.  Fortunately nobody died, but it was a matter of luck.  This was a timber framed building which was unable to resist the flames once they entered the cavity.  Just one month later, another timber framed building – Worcester Park in London – burnt to the ground.  

In November, there was a serious fire at The Cube in Bolton.  This student accommodation block was covered in high pressure laminate (HPL) cladding, below which was plywood covered with a combustible membrane.  The document concludes that HPL presents less of a danger than ACM, and therefore the latter should take priority.  This should then be followed by “immediate action to remediate unsafe HPL panels.  Whilst it is a positive thing that the risk from other types of panels has been acknowledged, the fact remains that they still present a risk, and in view of the incident at Bolton, there is a case for tackling their removal alongside ACM.  At present the removal of ACM is so slow, the removal of HPL will lie in the distant future if it has to wait for all ACM to be dealt with first.  There is therefore a possibility that it may never be removed.  Although the need to speed up the pace of remediation is acknowledged, nothing will happen without the necessary funding and the passing of legislation to make it mandatory for building owners to act.

Vulnerable Occupants 

There are other considerations too.  It is rightly acknowledged that Category 3 metal composite material cladding presents a significant fire hazard on residential buildings of any height and with any type of insulation, even mineral wool.  Therefore, the type of cladding as was used at Grenfell can never be safe.  However, when it comes to Category 2 cladding; that is metal composite panels with a fire retardant filler, but used with rigid foam insulation, it is considered unsuitable for buildings over 18m high.  Therefore, potentially it’s use would be permitted on buildings below 18m, even if only just below the threshold by a few centimetres.  However, if the building has vulnerable occupants, then Category 2 is not considered appropriate for buildings of any height.  This then begs the question as to who or what constitutes a vulnerable resident, and what type of building they might reside in.

A vulnerable person is generally considered to be one who is not able to evacuate without assistance, and may not simply be someone with the obvious mobility impairments.  It will include young children, pregnant women, the elderly, people with heart conditions, those with sight and hearing problems, people with mental health issues and so on.  The chance of any multi-storey, multi-occupied property not having any vulnerable people is extremely low, and given the diversity of issues which impede self-evacuation, it should be assumed that in all residential buildings there will be at least one occupant who falls into this category. 

Given the apparent ambiguity in the document about the definition of a vulnerable person and where they are likely to reside, it is worth noting that it says in Paragraph 2.7 that “the vulnerability of occupants is a significant factor in assessing this risk and, in some instances, may be more significant than building height.”  Considering how important this issue is, it ought to be acknowledged that the full extent of the risk is much wider than seems to be have been realised.

Balconies and Projecting Features 

Section 7 of the document is concerned with the risk posed by balconies, the hazard from which is present in a number of forms.  There have been several fires in the UK and abroad which have started on balconies and later spread to the rest of the façade.  Carelessly discarded cigarettes and barbecues are common causes of ignition.  Balconies are also often used for storage, and these items will add to the fire load should such an incident occur.

The other issue with balconies is that they protrude from the building face.  In Paragraph 3.12 of the document it is stated that “building from” should be taken into consideration when assessing the risk presented by the design and construction of the external wall.  The next paragraph, 3.13 states that “Assessments of the external wall should also include assessment of the potential impact of any attachments to the external wall.  Particular attention should be paid to any risk of fire spread from balconies and other attachments containing combustible materials.”  The reader is then referred to Section 7 for further advice.  The risk posed by projecting features is therefore recognised to an extent – which is encouraging – but the true nature of the risk and its potential consequences is not fully understood.

It may be the case that two high-rise buildings are covered in the same type of ACM cladding, but one poses a greater risk than the other. simply due to its shape, form and features

In my research report, “The Relationship between Building Design and Fire Spread: How the shape, form and features of a building can influence the behaviour of fire,” the influence of all projections, including balconies is considered.  Features such as columns, pilasters, string courses and cornices present a significant risk because the fire will have a tendency to cling to these features and the fire spread will intensify.  The fires which occurred at Grenfell Tower in London, the Olympus Tower in Grozny (Chechnya, Russia) and the Monte Carlo Casino & Hotel in Las Vegas (USA) are all examples of buildings where the fire spread was influenced by projecting features.  In all these cases, the fire spread would not have been as extensive if projections covered in combustible material had not been present.

It is therefore of utmost importance that the Government recognises this risk and places a greater emphasis upon it.  A few vague paragraphs in the advisory document does not go far enough and does not enable the building owner to understand the risk.  An advisory note on shape, form and features would be invaluable in assisting building owners to accurately recognise the risk posed by their building’s façade.  I have developed a risk assessment which considers building shape, form and features in conjunction with materials, type of construction, fire protection measures and firefighting fatalities.  This assesses both the qualitative and quantitative risk.  On a positive note, it is worth recognising that the document encourages an holistic approach to risk assessment, emphasising the importance of a collective approach to the effect of fire safety measures.

The Stay-Put Strategy 

In Section 11 there are a series of recommended checks a building owner should carry out, which include for example, facilities provided for firefighters, smoke control systems, flat entrance doors and smoke alarms.  In Paragraph 11.17 it is then advised that a competent person can assess whether a stay-put strategy is still appropriate for the particular building.  The paragraph then goes on to give a long list of factors which the competent person should take into account.  Examples include the height of the building, the ability of residents to evacuate without assistance, risk of external ignition of the cladding system and risk of internal ignition of the cladding system.  However, nowhere does it refer to the shape, form and features of the building and the way in which the fire might behave and spread on the façade.

At Grenfell, the firefighters turned up at the scene not knowing what to expect.  They had no way of knowing how the fire would spread and behave on the façade, and consequently this affected their ability to deal with the situation appropriately.  If the spread and behaviour of fire could be predicted, firefighters would arrive at a fire knowing what to expect and could plan their strategy accordingly.  Not only would this enable them to tackle the fire more effectively, but would help them make decisions regarding evacuation.  If it could be realised that the fire spread would be rapid and extensive, and compartmentation would be breached (ie by fire breaking in through the windows), a decision for the building to be evacuated could be made at an early stage, thus saving many lives.

This is one of the benefits of my research into the relationship between building design and fire spread, because it is now possible to predict how a fire will behave on a building with a combustible façade.

Remediation of Dangerous Buildings 

As an interim measure it may a good idea to remove combustible materials from all projecting features and recesses (which also present a serious hazard) on the facades of buildings with combustible cladding.  Considering the slow progress with remediation, something needs to be done to reduce the risk presented by the façade itself.  In such cases, if a fire was to occur, its spread would be restricted and people will have a chance to leave the building.  This would also allow for all types of flammable materials to be dealt with simultaneously (eg ACM and other types of metal composite panels, as well as HPL).  It would also prove cost effective in the short term, although the tendency for owners to pass the cost to residents would still remain a problem. 

Everyone has a right to a safe home, and if people bought their flats in good faith expecting them to be safe, they should not have to pay for the rectification of safety issues which have since arisen.  As the advisory document says in Paragraph 1.6, “building owners and managers of multi-occupied residential premises … must consider and rectify the risks of any external wall systems,” thus implying that it is the owner’s responsibility to make the building safe.

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About the author:

Frances Maria Peacock is a Chartered Architectural Technologist and a Fire Engineer.  Since the Grenfell Tower Fire of June 2017, she has been involved in research to examine the relationship between building design and fire spread, and has written several technical papers and reports which have been submitted to the Grenfell Tower Inquiry.  Frances is a member of the Institution of Fire Engineers, the Society of Fire Protection Engineers, the Chartered Institute of Architectural Technologists and the Institute of Historic Building Conservation.  She also has membership of the Royal Institute of British Architects.  Frances is a member of several fire safety task forces and committees, including the Standards Setting Committee of the International Fire Safety Standards Coalition.

Copies of my report, including the risks assessment, can be obtained by sending an email to fmpdrawings@gmail.com