Building Scotland (Amendment) Regulations 2022 - fire safety and cladding: presentation

Text version of a presentation on fire safety and cladding standard changes from February 2023 in the Building Scotland (Amendment) Regulations 2022.

This document is part of a collection


An update on the 2022/23 changes to building regulations

Fire Safety Standards from 1 June 2022

Introduction

The Building Scotland (Amendment) Regulations 2022 came into force on 1 June 2022 and amend regulations and standards on fire safety.  Changes to the regulations, standards and supporting guidance relating to external wall systems were published on 6 May 2022.

The key changes relate to Section 0 (general), Section 2 (fire) and Appendix A (defined terms) contained in both the domestic and non-domestic technical handbooks.

The regulations apply to new buildings, conversions and to existing buildings where building work is proposed. Building regulations do not apply retrospectively to existing buildings.

Key changes

Key changes to legislation with regard to the fire safety of external wall systems are:

  • the introduction of a ban on the use of combustible materials in external wall cladding systems on dwellings and on other defined ‘relevant buildings’ with a storey at a height of 11 metres or more. For such buildings, BS 8414 can no longer be used as an alternative means of compliance with building regulations.
  • a ban on the use of highly combustible metal composite material in an external wall cladding system or used as an internal lining on any building regardless of height;
  • replacement cladding on buildings is now subject to current standards and requires a building warrant. Like-for-like cladding replacement is now limited to minor repair work. This reflects the expectation that, to manage risk, such work should meet current standards and be subject to scrutiny by local authorities.
  • amendment to building standard 2.7 relating to the spread of fire on external walls to clarify the intent of the standard with regard to the height, use and position of the building.

Background

The Building and Fire Safety Ministerial Working Group was set up immediately after the Grenfell Tower Fire (2017) and have introduced a range of measures including:

  • in October 2019, we strengthened our guidance in relation to combustible cladding, means of escape and measures to assist the fire service.
  • in March 2021, we introduced legislation to install automatic fire suppression systems in all new build flats and maisonettes, social housing dwellings and multi-occupied shared residential buildings.

Since 2005, the guidance in support of building regulations required cladding on high rise domestic buildings above 18m to be non-combustible or the cladding system must pass a large scale fire test.

Following the Ministerial Working Group on Building and Fire Safety in March 2021, a need was identified to take precautionary action on both the highest risk cladding material and the use of large scale fire test results in new development. Accordingly, as an interim measure, changes were made to the Technical Handbooks from 1 April 2021 to identify the need to avoid use of highly combustible metal composite material panels in new building work and to remove reference to BS 8414 (and associated BR 135) as alternative guidance.

Since 1 April 2021, the Scottish Government Building Standards Division (BSD) have requested notification from local authority verifiers under section 34 of the Building (Scotland) Act 2003 where BS 8414 (and associated BR 135) and extended field of application assessments (BS 9414) have been used to demonstrate compliance with the mandatory building standards.

The Building Standards (Fire Safety) Review Panel 2020/22 was convened on 11 December 2020 and has met four times. The group comprises representation from a variety of experts from organisations including academia, professional institutions, local authority building standards, fire testing, research and consultancy, Scottish Fire and Rescue Service and the National Health Service. The UK, Welsh, Northern Irish and Irish Governments, as well as Scottish Government officials also attend the meetings.

A public consultation exercise, ‘Building standards (fire safety) - a consultation on external wall systems’, was undertaken from 16th July 2021 to 11th October 2021 and included the use of BS 8414. An independent consultation analysis by Optimal Economics was published on 17 January 2022.

The final review panel meeting was held on 24 January 2022. The Building (Scotland) Amendment Regulations 2022 were laid in the Scottish Parliament on 22 April 2022. These changes form part of the output from the Building Standards (Fire Safety) review panel and measures proposed within the 2021 consultation. The regulations have introduced a ban of metal composite material panels on all buildings regardless of height and ban other combustible cladding systems on residential and other high risk buildings over 11 m from 1 June 2022.

Ban of highly combustible metal composite material

Highly combustible metal composite material (Grenfell style cladding) is banned in Scotland for all buildings regardless of height both inside and outside buildings.

Regulation 8 of The Building (Scotland) Amendment Regulations 2022 provides the following definition, included in Appendix A defined terms of both technical handbooks, for such material:

“Any panel or sheet, having a thickness of no more than 10 mm, which consists of a number of layers, two or more of which are made of metal, alloy or metal compound and one or more substantial layer of which is made of a material having a gross calorific value of more than 35 MJ/kg when tested in accordance with BS EN ISO 1716:2018 entitled “Reaction to fire tests for products – Determination of the gross heat of combustion (calorific value)” published by the British Standards Institution’.

Such panels are generally very thin. Normally used in a rainscreen cladding system and may incorporate phenolic foam, polyisocyanurate foam (PIR) or stone wool.

There are 3 types of MCM

  • unmodified polyethylene core (the type found on Grenfell) – Cat 3 in UK Gov large scale fire tests
  • FR Grade – Fire retardant grade which incorporate mineral content to the polyethylene (say 60% mineral content) – Cat 2 in UK Gov fire tests
  • A2 – for example 95% mineral content 5% polyethylene – Cat 1 in UK Gov fire tests

Test 1 ACM (PE) unmodified core failed on 6 minutes and 35 seconds after the start time with flames off the top of the 8 m high test rig (termination criteria).

Important to note that this failure occurred regardless of the type of insulation material in the cavity (including where fire barriers were present).

In contrast Test 6 with A2 MCM Cladding and A2 stone wool passed the large scale test after 60 minutes

  • Reference is made throughout the technical handbooks to confirm the prohibition, in standards 2.5, 2.6 and 2.7:

‘The use of highly combustible metal composite material panels referred to and defined in Regulation 8 of the Building (Scotland) Amendment Regulations 2022 is prohibited.’

Ban of combustible external wall cladding systems for ‘relevant buildings’ or ‘specified attachment’

The introduction of a ban on the use of combustible materials in external wall cladding systems on dwellings and on other defined ‘relevant buildings’ with a storey at a height of 11 metres or more.

  • ‘Relevant buildings’ include dwellings (houses, flats, maisonettes), places of assembly, entertainment or recreation, hospitals, residential care buildings, sheltered housing complexes and shared multi-occupancy residential buildings such as student accommodation.
  • ‘Specified attachment’ includes a balcony, solar shading , a solar panel, attached to an external wall.
  • “External wall cladding system” is defined in standard 2.7 of the technical handbooks along with commentary of the wider meaning of specified attachment in 2.7.2 of both.
  • A list of exemptions for components of an external wall cladding system are included in appendices of the technical handbooks.
  • Annex 2.B reaction to fire from the domestic handbook confirms that large scale facade test BS 8414 may be used as an alternative to European Classification A1 or A2 where the external wall cladding system of a domestic building is less than 1 m to the boundary and the building has no storey at a height of 11 m or more above the ground.
  • Annex 2.E reaction to fire from the non-domestic handbook confirms that the BS 8414 test may be used as an alternative to European Classification A1 and A2 in the following situations: non-relevant buildings having a storey at a height of 11 m or more above the ground; hospitals, care homes, entertainment buildings and assembly buildings having a storey at a height of less than 11 m above the ground.

Replacement cladding

  • Schedule 3 to regulation 5, has been amended to require a building warrant where an external wall cladding system is being replaced. As a consequence, the replacement cladding must meet current building regulations. This reflects the expectation that, to manage risk, such work should meet current standards and be subject to scrutiny by local authorities.
  • Minor repairs to external wall cladding systems may still be carried out without a building warrant and on a like-for-like basis under work type 25 A of schedule 3 (subject to Regulation 8). A minor repair means an ‘isolated repair or replacement of elements of cladding which are physically damaged or have degraded to the point that the element is no longer fit for its intended purpose.’
  • Type 17 of schedule 3 has been amended to require a building warrant for thermal insulation associated with an external wall cladding system.

Standard 2.7 Spread on external walls

“Every building must be designed and constructed in such a way, having regard to the height, use and position of the building, that in the event of an outbreak of fire within the building, or from an external source, the spread of fire on the external walls of the building is inhibited.”

Additional wording has been added to building standard 2.7 relating to the spread of fire on external walls to clarify the intent of the standard with regard to the height, use and position of the building. This better aligns the intent of the standard with the associated guidance i.e. the guidance allows combustible materials in certain situations which without reference to height, use and position, could be seen as conflicting with the mandatory standard which requires fire spread to be inhibited.

The meaning of external wall cladding systems (EWCS) is explained.

  • the structural support to the frame for sheathing or backing board relates to the buildings structural stability where for example it is provided for racking
  • (horizontal) resistance, this is not considered part of the EWCS.
  • the previous noted list of exemptions exists for components which are considered part of the EWCS.

Other notable changes

Clause 2.0.9 (European Classification F materials)

  • clause re-written to include reference to European Classification F and further explanation provided in annex 2.B of the domestic technical handbook and annex 2.E of the non-domestic technical handbook.
  • this recognises the change in test classification where class F now meets performance criteria.
  • within standard 2.4 use of class F materials within a cavity, for example insulation within an external wall cavity in a building less than 11 m in height, means barriers are required at 10 m centres. But 2.4 needs to be considered along with other standards (2.2, 2.6 and 2.7). With regards to 2.6 and 2.7 guidance recognises the relative poor performance of class F materials and does not permit class F outer cladding materials.

Clause 2.0.10 Independent third party certification and accreditation

Re-written to add clarity with reference to useful sources of guidance such as the ‘Guide to undertaking technical assessments of fore performance of construction products based on fire test evidence’ (Passive Fire Protection Forum, 2021).

Clause 2.2.10 and Clause 2.1.15 from domestic and non-domestic technical handbooks, respectively

Additional guidance has been provided on technical assessments and junctions with walls, when considering separation and compartmentation detailing. See example in annex 2.E of the Non-Domestic Technical Handbook.

Clause 2.A.2 and 2.D.4 from domestic and non-domestic technical handbooks, respectively

  • reference to BR 128 removed.
  • material properties and assumptions at time of publication (1988) potentially outdated and therefore risks in use.

Clause 2.B.3 and 2.E.3 from domestic and non-domestic technical handbooks, respectively

  • • reference to classified without testing process updated.

Appendix A defined terms

New Regulation 8 definitions included for

  • highly combustible metal composite material
  • relevant building
  • specified attachment
  • substantial layer

Definition for Hospital updated for consistency with the NHS technical definition.

Contact for further queries: benny.rooney@gov.scot

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