External wall systems in existing multi-storey residential buildings - fire risk: advice note - version 2

Introduction

Purpose

The purpose of this Advice Note is to assist in determining the fire risk posed by external wall systems in existing multi-storey residential buildings. This will require a fire safety risk assessment and an appraisal of the external wall system which may include an intrusive investigation. The aim of both are to ensure that people are not placed at undue risk of harm as a result of fire spread over or within the external wall system. This Advice Note is concerned with life safety.

For the purpose of this Advice Note, an external wall system includes the outer cladding, cavity/fire barriers, insulation material behind the outer cladding, spandrel panels, window infill panels, balconies, solar shading and any other architectural feature or attachment to the building structure.. The main body of this Note deals with cladding systems and Annex 1 contains information on other external wall system features.

Who is the Advice Note for?

This Advice Note is for all those involved in determining the fire risk posed by external wall systems in multi-storey residential buildings. It is structured so that:

Part 1 (General Advice) will be of particular interest to those with responsibility for fire safety, such as building owners (including individual flat owners in privately owned/mixed tenure blocks of domestic flats), employers, building managers and others.

Part 2 (Technical Advice) will be of particular interest to those who undertake fire safety risk assessments and appraisals. Only suitably qualified professionals with the right skills, qualifications, experience, knowledge and behaviours should undertake such work.

Scope

This Advice Note applies to existing multi-storey residential premises of two or more storeys (including residential premises contained within "mixed use" buildings), for example:

• Blocks of domestic flats (including sheltered, extra-care and supported flats);
• Student accommodation (including halls of residence);
• Hospitals or other premises with overnight patient accommodation;
• Care homes;
• Hotels and hostels;
• Prisons.

Context of the Advice Note

Determining the risk to life from the spread of fire on external wall systems is just one element which needs to be considered as part of a fire safety risk assessment. The fire safety risk assessment is a wide ranging exercise which involves a methodical and holistic consideration of all fire hazards, risks and safety measures which impact on life safety. Existing fire safety measures must be evaluated and a judgement made on whether they are adequate or if more needs to be done to ensure the safety of people from fire.

This Advice Note supplements existing risk-based fire safety guidance and must be considered in that context. To ensure a holistic, risk-based approach to fire safety, the reader should also refer to the fire safety guidance below. These guides explain the fire safety risk assessment methodology in detail. They also highlight a wide range of potential fire hazards/risks as well as preventive and protective fire safety measures to reduce risk:

• Practical Fire Safety Guidance for existing premises providing sleeping accommodation;
• Practical Fire Safety Guidance for existing care homes;
• Practical Fire Safety Guidance for existing high rise domestic premises;
• Practical Fire Safety Guidance for existing specialised housing and similar premises.

Summary of changes to Advice Note (Version 2.0)

It is envisaged that this advice note may be updated as learning from the Single Building Assessment (SBA) programme evolves. The key changes to Version 2.0 are:

• Foreword updated and re-ordered;
• Document updated to reference PAS 9980:2022 as a source of additional information on fire risk appraisals and to support the implementation of the SBA programme in Scotland;
• Minor editorial changes throughout including updated reference to standards;
• Reference to recent changes to building regulations updated and historical information on BS 8414 moved to Annex 4;
• Definition of highly combustible Metal Composite Material (MCM) cladding updated to reflect changes to building regulations;
• Table 2 introduced on 'Examples of typical external wall systems on residential buildings';
• New section 2.5 on risk rating of external wall systems added;
• Addition of substantive Annex 5 'Practical Guide to the Appraisal of External Wall Systems in Residential Buildings';
• Flowchart replaced with new flowchart at Annex 6 describing the External Wall System Appraisal process.

Fire Safety Law

Fire safety legislation in Scotland applies to most existing non-domestic buildings which are classed as "relevant premises" under Part 3 of the Fire (Scotland) Act 2005. This includes residential premises which provide sleeping accommodation, such as care homes, hospitals, hotels, hostels, prisons and student accommodation etc. A fire safety risk assessment is a legal requirement for "relevant premises" and must "identify any risks to the safety of relevant persons in respect of harm caused by fire", including those posed by external wall systems.

Although not a legal requirement in Scotland, a fire safety risk assessment can be carried out for blocks of flats and is already recommended in Scottish Government guidance as good practice for high rise blocks and specialised housing. Scottish Government guidance encourages building owners, or individual flat owners where no single building owner exists, to take on a wider responsibility for their building's fire safety than is currently required under Scottish fire safety law. In terms of domestic premises, references in this Advice Note to "those responsible for fire safety" does not therefore imply any specific statutory obligations for fire safety beyond the existing duty to maintain common areas and existing firefighting facilities, as required under the Fire Safety (Scotland) Regulations 2006 and to keep common areas free from combustible material and obstructions under the Civic Government (Scotland) Act 1982. See Annex 2 for more information on fire safety legislation.

Fire Incidents

Situations where fire spreads beyond the flat of origin are very uncommon and are invariably the result of failings in building construction. Scottish fire statistics published by the Scottish Fire and Rescue Service (SFRS) show that no more than 1% of accidental dwelling fires in multi-storey residential buildings spread beyond the floor of fire origin. Most fires are, in fact, limited to the room of origin. There have been no accidental fire related deaths beyond the dwelling of fire origin since the inception of SFRS in 2013.

However, there have been major incidents in England where external fire spread has contributed to fatalities at Lakanal House in 2009 and Grenfell Tower in 2017. In 2019, rapid external fire spread was observed at 'The Cube' student accommodation in Bolton, where a number of rescues by Greater Manchester Fire and Rescue Service were necessary. Compliance with building and fire safety legislation and best practice guidance is key to minimising the risk to life from fire.