Life Critical Fire Safety External Wall System LCFS EWS

The government Official Statistics:Technical notes and definitions published 20 March 2025 states that for the purposes of its return 'Life-critical fire safety defects' are taken to mean; "defects, shrinkages, faults or other failings (on their own or in conjunction with other defects, shrinkages, faults or failings) in a building, which give rise to fire safety risks which are assessed as not “medium - tolerable” (or better) by a Fire Risk Appraisal of External Wall (FRAEW) undertaken in accordance with PAS 9980 (in relation to external wall construction or cladding) or assessed as high risk or medium risk by an equivalent Fire Risk Assessment (FRA) according to industry standards covering other parts of the building."

Whilst the phrase Life Critical Fire Safety External Wall System (LCFS EWS) appears in a number of building safety reports, articles and updates, a formal definition is not so clearly published. This is partly because it relates to the assessment of a situation by a competent person in its context as opposed to a simple definition. As such an understanding and indication of what it means in the context of various formal building safety processes is described here.

Primarily the assessments are of the risks to life that are associated with particular external wall systems (EWS) "made up of the outside wall of a residential building, including cladding, insulation, fire break systems, etc." (RICS Cladding External Wall System (EWS) FAQs 21 March 2025).

Following the Grenfell Tower Tower fire in June 2017, the cladding on the building, which formed part of the EWS was immediately identified as one of the contributing factors in the rapid fire spread across the outside of the building in particular the used of aluminium composite material (ACM) system. After the Grenfell Tower fire, the focus was on removing aluminium composite material (ACM) from buildings over 18 metres.

Following a testing programme, an expert panel made the following assessment of the three categories of ACM and the level of hazard or threat to the safety of life they represent, described here :

1. Category 1 ACM: Limited combustibility filler and be used safely, although also dependent on how it is fitted.
2. Category 2 ACM: Fire-retardant filler may be used safely with non-combustible insulation and appropriately fitted cavity barriers. The safety of this category is highly dependent on the insulation used, and how it is fitted.
3. Category 2 ACM Unmodified polyethylene filler with any type of insulation presents a significant hazard on buildings over 18m and should be replaced.

Extracted from London Assembly Residential buildings over 18m with ACM cladding on GLA Group estate.

However the attention given to external wall systems (EWS) later broadened beyond just ACM cladding, to include other types of combustible cladding. The government Advice Note 14 (December 2018) contained guidance for building owners on steps to take to tackle non-ACM materials on the external walls of high-rise buildings. Owners were advised to check “general fire precautions” and ensure external wall systems were “safe”.

In 2019 with concerns that flats in high-rise blocks wouldn’t represent good security and owners could be liable for remediation costs, enders began to seek assurance on the safety of external wall systems as a condition of approving mortgage applications. An increasing number of mortgage applications were rejected, sales started to fall through and in some cases buildings were valued at significantly lower than asking prices or even zero. The Royal Institution of Chartered Surveyors (RICS) responded with a cross-industry working group to consider best practice in the reporting and valuation of tall buildings within the secured lending arena with a view to agreeing a new standardised process. The process agreed in December 2019 was the EWS1 process and its complimentary form described as an “industry-wide valuation process which will help people buy and sell homes and re-mortgage in buildings above 18 metres (six storeys).(The Cladding External Wall System (EWS) (Constituency casework published Monday, 05 June, 2023)

The EWS1 form and process require a suitable competent expert to assess for likelihood of proportionate remediation to address fire safety risk. The EWS1 form is for the external wall system only, though is not a life safety certificate. and should not be taken as confirmation that other works relating to fire safety in other parts of the building are not required. The form gives simply two options; A and B (with notes):

• OPTION A "Where external wall materials are unlikely to support combustion" and in relation to attachments to the external wall (one of the following):
  • OPTION A1 – There are no attachments whose construction includes significant quantities of combustible materials (i.e. materials that are not of limited combustibility (Note 5) or better).
  • OPTION A2 – There is an appropriate risk assessment of the attachments confirming that no remedial works are required.
  • OPTION A3 – Where neither of the above two options apply, there may be potential costs of remedial works to attachments (Notes 7 and 8).
• OPTION B "Where combustible materials are present in external wall" and that using reasonable skill and care that would be expected of the relevant professional advisor to assess the level of fire risk (Note 8) presented by the external wall construction and attachments (one of the following).
  • OPTION B1 – (the assessor) has concluded that in their view the fire risk (see notes) is sufficiently low that no remedial works are required.
  • OPTION B2 – (the assessor) has concluded that in their view the fire risk (see notes) is sufficiently high that remedial.

Furthermore fire safety can also be impacted by elements that are not related to external wall systems (EWS) or non-EWS. The government Official Statistics:Technical notes and definitions published 20 March 2025 also refers to these defining them as "Other Fire Safety Defects (non-EWS)" saying:

"Other Fire Safety Defects’ may include, but are not limited to":

• Defective walls, ceilings or floors that can cause a loss of compartmentation between dwellings or between dwellings and common parts
• Inadequate/defective fire doors
• Inadequate fire stopping around cables or pipes
• Incorrect or missing fire escape signage
• Inadequate/defective fire detection and alarm systems
• Unprotected means of escape
• Inadequate/defective firefighting equipment or installations

[edit] Related articles on Designing Buildings

• ACM cladding testing by BRE.
• Accountability.
• Accountable person.
• ACM cladding.
• Approved Document B.
• BS 8414 Fire performance of external cladding systems.
• BS 9999: Code of practice for fire safety in the design, management and use of buildings.
• BS 9991:2015 Fire safety in the design, management and use of residential buildings. Code of practice.
• BS EN 13501-1.
• Building regulations.
• Building safety agreement with developers.
• Building Safety Regulator.
• Celotex RS5000 PIR insulation.
• Cladding for buildings.
• Composite cladding.
• Duty holder.
• EWS1 forms not required for buildings without cladding.
• Fire.
• Government building safety remediation data releases.
• Government response to the Building a Safer Future consultation.
• Grenfell articles.
• Grenfell Tower Fire.
• Hackitt review of the building regulations and fire safety, final report.
• Health and safety file.
• Housing (Cladding Remediation) (Scotland) Act 2024.
• Principal accountable person.
• Principal contractor.
• Fire Risk Appraisal of External Wall FRAEW.
• RSH September 2024 fire safety remediation report for English social housing.
• RSH March 2025 fire safety remediation report.
• The importance of digitising data to support cladding remediation and facilitate safer housing