Consultation outcome

Government response: review of the ban on the use of combustible materials in and on the external walls of buildings

Updated 1 June 2022

1. Introduction

1. On 29 November 2018 the government introduced regulations (SI 2018/1230) which came into force on 21 December 2018 and banned the use of combustible materials in and on the external walls of buildings.

2. The Statutory Instrument amended the Building Regulations 2010 and restricted the use of materials in an and on the external walls of certain buildings to those achieving the two highest reaction to fire classifications (Class A2-s1,d0 and A1). The ban applies to building work, in buildings with a storey at least 18 metres above ground level that contain one or more dwellings, an institution, or a room for residential purposes (excluding hostels, hotels, or a boarding house). The definition of building work is provided in Regulation (3) of the Building Regulations 2010 and includes the erection of new buildings and material changes of use. The priority was to improve public safety by removing the flexibility previously given to designers and making the route to compliance with the Building Regulations clearer for high rise buildings.

3. In the Explanatory Memorandum published alongside the Statutory Instrument (SI 2018/1230), the government committed to review the effectiveness of the ban through advice from bodies such as the Building Regulations Advisory Committee (BRAC). We conducted this review in the autumn of 2019 and engaged with experts including BRAC and industry partners to better understand views on the effectiveness of the ban and its impact on industry. This engagement included a study of the impact of the ban which took the form of an online survey to 100 relevant organisations, of which 34 responded. Most respondents reported difficulties with the implementation of the ban and sourcing alternative products. 65% of respondents considered the ban had provided benefits, with only 18% suggesting the detriments outweighed the benefits.

4. Discussions with stakeholders and the industry survey demonstrated a continued support for the ban. However, issues were raised including the scope of the ban and the list of exempted components. Issues noted by respondents included: an overly restrictive list of exempted components, lack of available compliant materials and increasing the complexity of construction detailing. The views gathered during the review informed the proposals for the consultation reviewing the ban.

5. Following completion of the review, the government proposed amendments to the ban, and launched a consultation in January 2020 seeking input on those proposals. The proposed changes focused on broadening the scope of the ban and amending the lists of specified attachments and exemptions. The consultation also sought views on a proposed ban of metal composite panels in and on the external walls of all new buildings or building work as defined in Regulation (3) of the Building Regulations 2010.

6. Following the analysis of responses to the consultation which closed on 25 May 2020, the government will introduce the Building etc. (Amendment) (England) Regulations 2022 to implement the following changes:

• Change the building types included within the ban - The legislation will bring hotels, hostels and boarding houses within scope.
• Metal Composite Materials - The legislation will introduce a complete ban on the use of the type of metal composite material that was used on Grenfell Tower (metal composite material with an unmodified polyethylene core) in the external walls of all new buildings and buildings undergoing building works, regardless of height or use.
• Attachments - The legislation will include curtains and slats of solar shading devices within scope of the ban, with a limited exemption for ground floor awnings.
• Exemptions - The legislation will amend the list of materials exempted from the combustible materials ban to include fibre optic cables and insulation up to 300mm from ground level. We will also provide an 18-month temporary relaxation for cavity trays in all forms of construction.
• Performance Requirements - The legislation will update the classification that materials must meet to comply with the combustible materials ban to the current version and allows the top layer of a balcony floor to meet the required standard using the horizontal-testing equivalent of the existing standard (which requires materials to be tested vertically).

7. We are also issuing an amendment to Approved Document B to introduce new guidance for external walls and balconies for residential buildings between 11m and 18m in height. This change will take effect in England on 1 December 2022. For further information on which building work will be affected and when the changes take effect, please see the amendment booklet.

2. The consultation

8. The consultation ran for 18 weeks from 20 January 2020 to 25 May 2020. The consultation documents were available online at GOV.UK and responses could be returned by email or post to the Department, or through an online survey.

9. The consultation complied with the duty on the Secretary of State in section 14(3) of the Building Act 1984 to consult the Building Regulations Advisory Committee and other bodies representative of the interests concerned on proposed changes to the substantive requirements in the Building Regulations.

10. This consultation proposed changes to requirements of the Building Regulations which in effect ban the use of combustible materials in and on the external walls of certain buildings and in specified attachments to the external walls. This consultation sought views and supporting evidence on the following:

• changing the building types covered by the ban
• changing the height threshold of the ban
• ban on the use of metal composite materials with a polyethylene core
• attachments
• changing the list of exemptions
• changing the performance requirements of the ban

11. There were 854 responses to the consultation, 376 of which were received from individuals and 299 from organisation representatives. 179 respondents declared as both individuals and organisation representatives.

12. Respondents were asked to assign themselves to one of 15 broad organisational type categories to help the analysis of the responses. Several respondents selected more than one category.

Responses by organisational category

• Architect - 32%
• Designer / Engineer / Surveyor - 17%
• Manufacturer - 15%
• Construction professional - 11%
• Trade Association / trade body - 6%
• Other - 5%
• Builder / Developer - 4%
• Fire and Rescue Authority representative - 3%
• Local authority - 3%
• Building occupier / Resident - 2%
• Building Control Approved Inspector - 1%
• Property manager / Housing Association / Landlord - 1%
• Insurer - 0%
• Landlord representative organisation 0%
• Tenant representative organisation 0%

3. summary of responses

Overview

13. This report is structured around the questions set out in the consultation document. Each section includes a quantitative analysis of the responses and a summary qualitative analysis of the views and comments submitted for each consultation question. The question numbers used in this report are consistent with the question numbers on the survey form.

14. It should be noted that none of the questions in the consultation received a 100% response. Every percentage given in the tables and text in this report is a percentage of the replies of those who answered the particular question and where responses could be coded into “yes/no/don’t know” out of the possible 854 respondents for consistency, unless stated otherwise.

15. The percentages are based on the full sample, with some of the findings summarised based on targeted analysis of responses from key stakeholders.

16. The percentages have been rounded to the nearest whole number. Some responses have not been included in the “yes/no/don’t know” responses as they were either “don’t know” or not written in a format where we could identify clearly the response provided.

Changing the building types covered by the ban

17. In section 4.1 of the consultation we proposed including hotels, hostels and boarding houses within the scope of the ban.

Question 3a - Do you agree that hotels, hostels and boarding houses should be included in the definition of relevant buildings in Regulation 7(4)? Please provide evidence to support your answer.

• 275 (38%) of respondents said “agree”
• 150 (21%) said “disagree”
• 295 (41%) said “don’t know”

18. 38% of the consultation respondents agreed that hotels, hostels and boarding houses should be included in the definition of relevant buildings in Regulation 7(4). 38 of the 275 respondents who said they agreed provided no reasons.

19. 201 respondents who said they agreed stated that they believed that hotel, hostels, and boarding houses present an equivalent, or greater, sleeping risk. Reasons given for this view included that:

• residents are unaware of their surroundings
• statistics show much longer awareness and movement times
• the occupancy includes elderly
• vulnerable and disabled persons
• some residents might be intoxicated
• there may be large numbers involved
• management inputs can be inconsistent
• hotels are increasingly used as temporary refuges
• some respondents considered it crucial that the structure stops rapid fire spread that could exceed the time required to evacuate such premises

20. Respondents also considered that recent fires in hotels and similar premises displayed dangerous features involving combustible materials and that simultaneous evacuation strategies and management do not offer sufficient safeguard.

21. Six respondents agreed with our proposal on the basis that in their view buildings should be future proofed for change of use and therefore designed to standards that are robust enough to accommodate future changes.

22. Of the 21% of respondents who disagreed with our proposal 13 provided no evidence to support their answer. A further 85 of the respondents felt that the ban should not be extended to such uses and that fire safety should be determined by a thorough risk assessment and a strategy determined on sound fire engineering design rather than blanket bans.

23. Thirty-seven of the respondents who said they disagreed considered this group of accommodation use as being of less risk due to the inherent ADB strategies and higher levels of management. It was also suggested that National Fire Statistics do not indicate a high rate of fire incident within this use group.

24. 41% of respondents answered that they ‘Don’t Know’ if hotels, hostels and boarding houses should be included within the ban. 123 of these respondents mentioned that any fire safety design should be determined by a risk assessed approach.

Question 3b - Should any other building types be included within the scope of the ban? Please provide details and evidence to support your answer.

• 163 (23%) of respondents said “yes”
• 201 (28%) said “no” and
• 356 (49%) said “don’t know”

25. 23% of the consultation respondents said that other building types should be included within the scope of the ban and suggested many other building uses and typologies. Of these respondents who answered yes, seven respondents further mentioned the concept of future proofing.

26. Although specialist housing is already included within the scope of the existing regulations, respondents proposed that housing vulnerable should be specifically included. Schools were also mentioned by 38 respondents. These building types were both seen as worthy of coverage across any height of building.

27. The rationale provided by respondents for the inclusion of specialist housing was based on the following concerns:

• long awareness and response times apply to this residential sector
• the evacuation of vulnerable people is difficulty and takes considerable time
• management responses could be overwhelmed by events
• the duration of time needed for evacuation could outstrip tenable conditions and the period of structural fire resistance
• fire service intervention is showing as being imperative in many instances and even this is jeopardised by rapid fire spread

The above concerns were seen by many as being applicable to buildings in this category of any height.

28. The rationale provided by respondents for the inclusion of schools was based on the following concerns:

• the potential for arson in schools
• loss of property asset and attendant public costs
• large numbers of occupants involved
• form of construction preferred in schools
• potential vulnerability of students
• concerns as to whether staff fire training is sufficient for all circumstances
• schools often embrace wider community/assembly uses

29. Other building types/uses mentioned by respondents included the following:

• any block of flats over 3 storey
• all flats with mixed use
• all buildings not using a simultaneous evacuation strategy
• all public buildings
• sports stadia
• all buildings without suppression systems
• all tall buildings (whatever the use)
• buildings with large compartment sizes
• places of assembly
• all public buildings
• all buildings of any heights

30. 28% of respondents answered ‘No’ to this question, of which 32 respondents provided no supporting evidence. Most respondents (68 responses) objected on the ground that fire strategies should be developed from thorough risk assessment of the proposal and not be based on unsubstantiated bans.

31. Twenty-five respondents were concerned about the adverse effect that such bans can have on the use of sustainable solutions and that this would hinder the evolution of materials and techniques.

32. Forty-eight respondents were concerned that such an extension of a blanket ban does not seem to have any evidential basis as to the degree of risk presented by other building uses. Neither was it seen as being a complete solution to the facade fire phenomenon.

33. 49% of respondents answered that they did not know whether other building types should be included within the scope of the ban. Amongst these replies 103 respondents further referenced the use of a building specific risk assessment method.

Changing the height threshold of the ban

34. In section 4.2 of the consultation, we proposed lowering the height threshold of the ban, to include buildings with a storey at least 11 metres above ground level. A research project was also proposed that would aim to improve our understanding of building risk in relation to height and other factors, in order to support an appropriate height threshold for the ban in the future.

Question 4a - Do you agree that the height threshold of the ban should be reduced to at least 11m and above?

Question 4b. Is there another lower height threshold that should be considered? Please provide evidence.

• 179 (24%) of respondents said “agree”
• 318 (44%) said “disagree”
• 234 (32%) said “don’t know”

35. 24% of the consultation respondents agreed that the height threshold of the ban should be reduced to at least 11m and above. The following justifications were provided for their answer:

• increases the safeguards for the larger number of residents in such buildings (over and above the small single stair building allowances) and the longer travel distances involved
• buildings in this range have been shown to be susceptible to modern external wall fires. some recent fire incidents have been extreme and have embodied rapid fire spread giving a need for accelerated, and difficult, simultaneous emergency evacuation
• warning systems are susceptible to complacency
• external firefighting capability including the likely presence of restricted perimeter access
• helps to mitigate against construction quality and specification misunderstandings
• consistency across UK
• provides public reassurance

36. Twenty-two respondents (3%) felt that the ban should apply to all buildings of any height. Reasons given related to general safety concerns and a view that functional requirements may not be robust enough.

37. Twenty-two respondents (3%) also suggested that the ban should apply to all buildings of any height accommodating vulnerable people (including schools) and used as places of public assembly.

38. Respondents also proposed there should be a separate set of rules or guidance for an intermediate zone of 11m-18m. Given that there is a large body of medium height buildings that fall with this range (i.e. that which falls between normal external firefighting capabilities and that which calls for internal firefighting via protected firefighting shafts) and that they display some common features, there were suggestions that a set of rules specific to their risks could be beneficially formulated. This could be graduated to consider a matrix of:

• external wall construction specification (which at present is allowed to include timber or other combustible materials)
• the possible provision of assured perimeter access allowing the use of high reach fire appliances
• the totality of fire risk from and firefighting capabilities in relation to the facades
• holistic fire strategy review of all risks and means of escape provisions

39. A large number of respondents (318, 44%) were against any extension of the ban both as a principle and that height alone is seen as a singular ‘blunt instrument’. Evidence provided for this view included the following:

• Risk assessed design – All of these responses proposed that fire safety strategies should be designed on a scientific risk assessed basis rather than a blanket ban.
• Clarity and distinction between cladding and structure – Many of these answers called for such a distinction to be made as they felt the overriding need is to prohibit cladding risks without creating unnecessary and unintended restrictions on primary structural elements.
• Timber and other materials – A similarly large number of responses considered that any ban should not hinder innovation, and any beneficial advancement, in the use of Cross Laminated Timber (CLT) and similar engineered timber structural products. Many references were made to the alleged satisfactory fire performance of CLT with cross references to the Eurocodes, fire testing and research papers and case studies of the fire design of existing CLT buildings (international and UK).

40. There was also strong concern from respondents that an 11m trigger height threshold would impact traditional timber framed buildings.

41. Numerous respondents referenced that any extension of the ban would also extend the currently perceived issues with the existing ban across a much wider range of buildings. References were made in the responses to technical, product and cost issues which could also impact the housing delivery and market. Some highlighted how the proposed change of height may impact on the viability of change of use and other significant refurbishments by creating significant technical issues.

Question 4c - Do you agree an appropriate research project regarding building risk should be carried out to inform further review of the scope of the ban?

• 650 (90%) of respondents said “agree”
• 25 (3%) said “disagree”
• 50 (7%) said “don’t know”

42. 90% of the consultation respondents agreed that an appropriate research project regarding building risk should be carried out to inform further review of the scope of the ban.

Question 4d - Please suggest the type of evidence you consider should be included in further review of the height threshold of the ban.

43. Suggestions regarding the type of evidence that should be included in a further review of the height threshold of the ban included the following:

Large scale tests

• research as to whether any passive and/or active fire safety systems can inhibit facade fires
• research on the use of BS 8414 which would include a targeted series of BS 8414 testing on common wall build ups
• develop a refined large-scale wall test that readily reflects actual building features

Whole building assessment including cost/benefit

• conduct a cost benefit analysis on the comparable fire safety and economic benefits between ban provisions and functional approaches
• assess the interaction of concurrent evacuation and fire fighting
• review of the pattern of spread and time function of façade fires
• review of the effect of building shape and size on fire spread
• develop a balanced assessment matrix that evaluates all Building Regulation objectives into a collective best requirement
• create a holistic risk matrix tool to evaluate overall fire safety
• produce guidance on design life and maintenance of vital fire safety elements

Engineered timber

• research the performance of Cross Laminated Timber (CLT) structures
• case study of existing buildings particularly in respect of CLT buildings

Wider research

• literature review
• detailed research on smoke toxicity
• consider the performance of current smoke control designs in respect of fires affecting multi floors
• research an alternative modelling methodology for the assessment of external wall fire performance and ancillary products
• research the interrelationship of cladding and structure under facade fires
• research on smoke toxicity
• consider the performance of current smoke control designs in respect of fires affecting multi floors
• study failure patterns of fire protection systems
• case studies of relevant fires
• the incidence, causes and prevention of fire sources external of a building
• evaluate firefighting capabilities in respect of façade fires in tall buildings
• study the effect of façade fires on means of escape and the validity of stay put strategies
• consider management effectiveness
• study the marketing and legal consequences of restrictive regulatory campaigns
• develop a balanced assessment matrix that evaluates all Building Regulation objectives into a collective best requirement
• create a holistic risk matrix tool to evaluate overall fire safety
• produce guidance on design life and maintenance of vital fire safety elements

Question 4e - Please provide any evidence you believe should be considered in further review of the height threshold of the ban.

44. The responses were a repeat, or a merge of replies made to Question 4d. Any relevant information provided in this question is presented in the analysis in question 4d.

Ban on the use of metal composite materials with a polyethylene core

45. In section 5 we proposed to ban the use of metal composite materials with a polyethylene core in and on the external walls and specified attachments of all buildings, regardless of height, purpose or use. This would include the aluminium composite material that was used as cladding on Grenfell Tower and similar materials.

Question 5a - Do you agree that metal composite panels with a polyethylene core should be banned from being used in external wall construction of any building regardless of height or purpose?

• 264 (48%) of respondents said “agree”
• 101 (18%) said “disagree”
• 188 (34%) said “don’t know”

46. The majority of respondents (48%) agreed that metal composite materials with an unmodified polyethylene core should be banned.

Question 5b - If no, why not? Please provide evidence to support your answer.

47. 18% of respondents disagreed that metal composite panels with a polyethylene core should be banned and provided the following reasons:

• The proposed ban is too singular, arbitrary, and wide as it does not capture other materials which may present a near similar risk or recognise any graduation of building risk. Other materials mentioned were:
  • Timber;
  • PVC cladding and windows;
  • any other plastics (such as polyethylene, polypropylene, etc.);
  • High Pressure Laminate; and
  • any other combustible materials.
• There are instances where the product could be used without there being an undue risk. This could safely apply to small and low-rise buildings with low occupancy and quick simultaneous evacuation strategies
• Risk assessment and the application of an engineered design approach could safely accommodate its continued use as a valued architecture material in carefully selected and controlled positions. This could avoid large facade expanses and its use close to exits.
• Control of materials should be via consistent performance criteria not piecemeal bans that might set a precedent. Limitation to one material might produce an allusion that all other materials are satisfactory
• Such a ban could instil a chain reaction of fear amongst building owners, insurers, and funders alike that might regressively be applied to existing buildings

Question 5c - If their use was to be restricted, do you agree with the proposed definition? Please provide evidence to support your answer.

• 108 (22%) of respondents said “agree”
• 107 (22%) said “disagree”
• 271(56%) said “don’t know”

48. The proposed definition was “metal composite panels with a core comprised of greater than 30% polyethylene by mass”. Most respondents (56%) said that they did not know whether they agreed with the definition.

49. The following suggestions were made concerning the robustness of the proposed definition and possible alternative approaches:

• Queries were raised over the evidence base for a 30% of mass allowance;
• Any such percentage allowance could result in variance of fire load due to variations in the properties of the outer skins of the cladding
• Prescribing any ban explicitly to the use polyethylene, or any specific stated material, could leave the door open to another high-risk alternative material being used for the same purpose such as polypropylene which would not meet the policy aim
• Suggestions were made that limits should be based on gross heat of combustion value of the core
• It was also suggested that performance could possibly be based on reaction to fire classifications graduated to the buildings risk profile (height, use, population, fire access, boundary conditions, etc.). This could be accompanied by controls on other wall components in the external wall specification.
• Concerns over toxicity were also mentioned.

Attachments

50. In section 6 we asked for views on the current list of specified attachments and proposed to extend the ban to include solar shading products, including but not limited to blinds and shutters.

Question 6a - Which components, if any, do you consider should be included in the list of specified attachments in Regulation 2(b) and why?

51. 339 responses were made to this question and covered the following aspects:

• Clarity - 43 responses were of the view that the scope of applicability within the term ‘specified attachment’ should be better explained, including clearer and more precise definitions in the Regulations and ADB. In particular the demarcation, if any is intended to apply, between projecting balconies, inset/recessed balconies, tiered/stepped balconies, terraces, walkways, etc. should be clearly set out so as to avoid further confusion and misunderstandings.

• Solar shading products - 16 respondents said that they should be included. 76 respondents said that they should not be included. Reasons stated not to include solar shading products were that there was no history of such products causing or contributing to a fire (UK and international), nor evidential basis to support the need for inclusion. It was also stated that the nature of the products does not lend themselves to normal fire test regimes and any changes that would impact on the industry would require a lengthy transition period. There was also a view that the environmental benefits are overriding in this consideration and these should not be diminished by an overreach of regulation.

• Other attachments - The following suggestions were made:

  • down pipes (5 responses)
  • electric lighting and services (8)
  • signage/hoardings (other than shop fronts) (17)
  • green walls (9)
  • canopies /porches (4)
  • architectural features such as Fins, Sky Beams, Wind Catchers, Light Reflectors, etc (5)
  • double skinned facades (3)
  • balcony dividing screens, podium fences, etc. (3)
  • any soffit not part of a balcony (3)
  • M and E plant (3)
  • awnings (2)
  • gas installations/pipework (4)

Question 6b - Do you agree with the proposed definition of solar shading products? If no, what other definition would you propose and why?

52. The proposed definition for solar shading products was “a device for reducing heat gain within a building by deflecting sunlight which is attached to an external wall”. Respondents answered this question as follows:

• 193 (35%) of respondents said “agree”
• 117 (21%) said “disagree”
• 236 (43%) said “don’t know”

53. Among the respondents who disagreed with the proposed definition, there was a strong body of opinion that it does not capture the many purposes of such attachments. In addition to reducing heat gain this could include many environmental and amenity benefits such as controlling glare, protecting from UV, privacy, etc.

54. Respondents stated that the definition does not recognise that such devices/products can be external, interstitial, and internal. Many respondents felt that any inclusion should not cover internal blinds and other movable or flexible components. It was felt that too wide a regulatory coverage was not necessary and should be avoided.

55. A widely mentioned alternative definition was tabled, as follows:

‘A fixed device for reducing heat gain within a building by deflecting sunlight which is attached to the external wall but excluding all devices that are mechanically openable, including blinds, shutters and awnings.’

Question 6c - Do you agree that solar shading products need to achieve class A2-s1, d0 or A1 in line with the requirements of the Building (amendment) Regulations 2018?

• 206 (38%) of respondents said “agree”
• 132 (24%) said “disagree”
• 210 (38%) said “don’t know”

56. Respondents asserted that the nature of dynamic shading products is different from fixed external brise soleil. They further stated that dynamic solar shading cannot currently be tested in line with the requirements of the ban.

57. Respondents stated that individual components and materials of dynamic shading devices are diverse and may be small. Many of the materials and components used (which might include plastics, fabrics and cords, actuators, and motors, etc.) would not pass reaction to fire tests procedures which are aimed at conventional construction products and risks. Some responses mentioned the potential use of modified BS 8414 test as a more appropriate route to test these products.

58. Respondents within this specialist industry viewed these inherent difficulties of assessment as being an unnecessary and problematic constraint. They also expressed views that there was no history of fire incidents involving dynamic shading installations.

59. Respondents stated that to redesign installations and restructure the industry to comply with the ban would be a difficult and very lengthy process, which in the interim would be detrimental to maintaining industry output and the achievement of its intended environmental purposes. Several respondents expressed concerns about the serious impact this would have on their business.

Question 6d - Do you agree that retractable awnings fitted to the ground storey should be exempted? If yes, what restrictions, if any, should be placed on these.

• 269 (49%) of respondents said “agree”
• 69 (13%) said “disagree”
• 212 (38%) said “don’t know”

60. The majority of respondents (49%) agreed that retractable awnings fitted to the ground storey should be exempted. A number of views were expressed that awnings should be exempt without condition. This was based on similar reasons than the ones highlighted in question 6 c).

61. Respondents offered the following suggestion for further exemptions involving solar shading devices:

• Limit materials to another classification than A2-s1,d0 or better which better suit textiles.
• Limit the area or mass involved by linking it to the rating of the material.
• Require a minimum distance for separation from openings above.
• Consider the relationship to other fire entry points into the building and the proximity of PVC windows.
• Protect any fire exits under or close to the awning.
• Exempt awnings when they are able to retract in the event of a fire or overnight . It was believed that this would reduce the level of risk when residents above may be asleep. It would also safeguard against any unawareness of an external ignition fire incident effecting an open awning at night.

Changing the list of exemptions

62. In section 7 of the consultation we proposed several changes to the list of exemptions in Regulation 7(3) including the temporary exemption of cavity trays in all forms of construction and the extension of the exemption of waterproofing and insulation materials. The consultation sought evidence-based views on additional exemptions, materials such as laminated glass, whether there are exemptions that should be withdrawn, and clarifications on exemptions such as roofing components.

Exemptions

Question 7a - Which components, if any, do you consider should no longer be included in the list of exemptions in Regulation 7(3) and why?

Question 7b - Which additional components, if any, should be included on the list of exemptions in Regulation 7(3) and why?

63. These two questions are reported in a collective manner as respondents merged their answers to both questions 7a and 7b. Responses to this question link to responses to Questions 6, 8, 9, 10 and 11.

64. The major themes raised within the responses to the questions included the following:

• Clarification - Many requests were made for clearer definitions. The following areas were raised as areas requiring better definitions membrane; distinction between membranes in external walls, specified attachments and roofs; distinction between a window and curtain walling.

• Assessment method for exemptions - Views were expressed that the route for exemptions was unclear and seen as being arbitrary. However respondents broadly supported that the inclusion of new exemptions on the basis of a robust scientific methodology that could include large scale wall testing under BS8414.

• Structural timber - Replies highlighted concerns that the ban limits the use, and development, of structural timber members such as Cross Laminated Timber when they are part of the external wall. Some respondent were of the view that engineered timber elements can demonstrate satisfactory fire safety performance through a number of methods.
  
  Respondents also expressed concern that any adjustment to the trigger height thresholds and/or widening of the scope would impact the use of traditional timber framed construction. The sustainable benefits of timber construction were strongly emphasised across this body of responses.

• Satisfaction with the list - Notwithstanding the suggestions for change made by respondents, there were a number of responses that were satisfied with the list as it stands.

• Exclusions - Specific suggestions made by respondents for matters that should be excluded from the current list of exemptions are as follows:
  • PVC windows
  • cavity trays for all types of constructions.
  • roof soffits and fascias
  • downpipes
  • membranes

• Fibre optic cables - Respondents provided a view that fibre optic cables would require an exemption as they carry an important function for households and they are pose a similar level of risk than electrical installations.

• Air bricks, vents sub floor ventilators and weep holes - The general view was that these should be exempt as they are not perceived as being of any risk. It was also noted that steel alternatives are much more expensive.

• Sealing tapes - Clarity was sought on whether sealing tapes could be considered as membranes and therefore exempt. Although some highlighted that if sealing tape was as a membrane then would be unlikely achieve B-s3, d0. Suggestions were that they should be totally exempt.

• Inclusions - Other matters requested for inclusion in the list of exemptions included the following:
  • Boiler flues
  • Laminated glass including spandrel panels in balconies
  • Solar shading
  • Weep holes
  • Air brick and vents
  • Fan terminals and mechanical vent ductwork
  • Water proofing upstands
  • Insulated upstand boards
  • Green walls on environmental grounds
  • Water proofing membranes
  • Protective coatings to BS EN 1504-2 material 1.3.6
  • Masonry paints
  • External Wall Insulation beads, profiles and reinforcing mesh

Cavity trays

Question 8a - Do you agree that cavity trays should, by temporary relaxation for 18 months, be exempted from the requirements of Regulation 6(3) and 7(2)?

• 176 (35%) of respondents said “agree”
• 81 (16%) said “disagree”
• 253 (49%) said “don’t know”

65. 35% of respondents agreed that cavity trays should be exempt from the requirements of Regulation 6(3) and 7(2). 49% of respondents answered that they did not know and 16% disagreed with this proposal.

Question 8b - If yes, what, if any, conditions should be imposed on their use?

66. A total of 183 respondents gave evidence to support their answer. Not all the responses given related to the ‘Yes’ answers. The most common themes and viewpoints raised in the responses were as follows:

• No fire risk - 44 respondents were of the opinion that cavity trays present very little or no unjustified fire risk due to the relatively small surface area of cavity trays, the corresponding low calorific load involved and that they are within non-combustible walling and encompassed by cavity barriers.

• Permanent exemption - 28 respondents considered that they should be permanently exempt.

• Evidence basis - While supporting the proposal, 33 respondents stressed that there was a definite need for further research both in terms of either supporting the policy or to give clarity and validity to any temporary or permanent amendment.

• An agreed specification - 32 respondents suggested that there might be scope for the development of an agreed specification based on the type of material, its fixings, and the extent and position of the component in the wall. Further research could help to develop such an approach.

• Design detailing problems - 17 respondents recorded that there were difficulties as there was no ideal alternative. Non-combustible trays are often unsuitable due to being difficult to shape, not accommodating movement, presenting more thermal bridging, having durability questions and do not have suitable verification for use.

• Product development - 13 respondents looked towards suitable product development and a few respondents reported of predicted progress in that direction. This included a view by some respondents that non-combustible steel cavity trays should be continued with. Increasing use and detailing would begin to establish satisfactory performance and certification. It was also felt that the accompanying use of sealants, tapes, etc might need further research/agreement.

67. While no time frame was mentioned, there were several respondents pointing out manufacturer’s current product development of steel trays and one concerned the development of polymer trays.

68. Thirteen responses were received with a mix of opinions as to an optimum duration of temporary relaxation. Some were of the view that it should only be 12 months to force along product advancement, most were happy with 18 months, while some suggested that two years was more practical. There were a few respondents who felt it should be open ended but monitored as to the progress of research and product development.

69. Some concern was expressed that a temporary relaxation could leave a residual risk, or lack of awareness of the constructed details, of buildings constructed in any interim period.

70. There was also some limited concern that in the face of current uncertainties, temporary solutions to the cavity tray issue are allegedly being applied within Building Control that could be seen as confusing the matter.

Laminated glass

Question 9a - Do you agree that laminated glass in balcony construction should continue to have to achieve A2-s1, d0 classification or A1?

• 140 (28%) of respondents said “agree”
• 134 (26%) said “disagree” and
• 231 (46%) said “don’t know”

71. The majority of respondents (46%) said that they did not know whether laminated glass should continue to achieve the current classification. 28% of respondents agreed and 26% disagreed.

Question 9b - Please provide evidence to support your answer where possible and discuss specific materials or products.

72. A total of 261 respondents provided evidence to support their viewpoint on this question. The common themes and viewpoints raised were as follows:

• Low fire risk - 74 answered that they considered laminated glass to be a low fire risk in the use of laminated glass to balcony balustrading and that any impact towards ignition, contribution to fire spread and/or delamination and collapse of panels or droplets was negligible.

• Window comparison - A further 22 answers saw an unwarranted anomaly between the ban of its use in balcony balustrading but with no control exercised over adjoining windows and doors.

• Confusion over classification - 17 answers suggested that there were questions surrounding the appropriateness of the classification method.

• Overriding benefit of laminated glass balustrading - 46 respondents stated that glazed balcony balustrading was frequently needed, above other balcony guarding formats, in order to provide prevention of falling, daylighting, protection from wind, view from accommodation and other amenity and aesthetic aspects. Respondents stressed that for safety reasons laminated glass is preferable to toughened glass which tends to shatter under impact and create a falling risk. These intrinsic benefits were widely believed to outweigh any slight fire performance doubts surrounding laminated glass.

• Research, evidence and solutions - 62 respondents recognised and called for a research programme to establish the extent of any risk and to develop an agreed solution that can accommodate the appropriate use of glazed balustrading. Respondents felt that such research be conducted in collaboration with the glass industry. Reference was made to the products and research work being done by various manufacturers and also the guidance available in TfL publications. Suggestions were made that any risk could be controlled by developing an agreed safe standard specification which may limit the reaction to fire performance of laminated glass, framing and fixing details and the area and position.

• Considered a risk - 22 respondents still considered that laminated glass could present a risk. This included concerns over falling panels and droplets as well as a view favouring upholding strict performance requirements.

Roof components

Question 10a - Do you agree that additional clarification in Approved Document B, that roofing membranes are not required to achieve A2-s1, d0 classification or higher when used as part of a roof connecting to an external wall, is not required?

• 144 (29%) of respondents said “agree”
• 124 (25%) said “disagree” and
• 231 (46%) said “don’t know”

73. 29% of respondents agreed that additional clarification in respect of roofing membranes requirements in Approved Document B is not required. Most respondents (46%) said that they did not know whether additional clarification was required and 25% disagreed and therefore thought that it was required.

Question 10b - If no, please provide an explanation with evidence to support your answer where possible and discuss specific materials or products.

74. A total of 187 respondents submitted evidence to support their answer. The common themes and viewpoints raised are as follows:

• Clarification - Almost all respondents mentioned confusion over the subject, the guidance and the wording of the consultation question. Resolution and clarification were desired by respondents, whereby once a requirement is conclusively set, it should be illustrated by a simple diagram in ADB.

• Identifying the risk - Opinion was evenly split between those who felt that the integrity of the ban should be upheld in all details and those who believed that no undue fire risk is presented by a normal waterproofing upstand formed by a roofing membrane (on the understanding that the rest of the wall and roof construction are compliant with their respective requirements).

• Most attention centred on roof to parapet junctures, but it was also highlighted that perhaps a higher risk might be presented at the podium level and terrace roofs, and inset balconies above accommodation, to external walls.

• Safeguarding the junction - A third of respondents explained that roof membranes do not and cannot achieve A2-s1, d0 or B-s3, d0 classification. Therefore, it is unlikely that any roofing product would be able to meet the performance requirement of the ban or associated products. Furthermore, it is noted that the fire performance of roof coverings is assessed in different terms and is subject to a different test regime.

• A number of respondents suggested safety could be achieved by the stipulation of limits on the height of upstand and the control of combustible insulation, or other products, within the adjacent roof build up.

Materials below ground level

Question 11a - Do you agree with the proposal of expanding the exemption of the use of water proofing and insultation materials from below ground level to up to 250mm above ground level?

• 505 (67%) of respondents said “agree”
• 41 (5%) said “disagree”
• 208 (28%) said “don’t know”

75. The majority of respondents (67%) agreed with the proposal to expand the exemption of the use of water proofing and insulation materials from below ground level to up to 250mm above ground level. 5% of respondents disagreed and 28% said that they did not know.

Question 11b - If yes, what other conditions should be imposed on their use if any?

76. A total of 201 respondents submitted evidence to support their answers. The common themes and viewpoints raised are as follows:

• Allowable height - It was widely agreed that the level of risk is low from such arrangements and an overriding need to ensure damp free and durable construction. There were various suggestions as to the height that is needed to achieve sound and practical waterproofing detailing in relation to differing ground levels, linkage with gas membranes and allowing for flood resilience.
  • The proposed 250mm was supported for level ground conditions but with suggestions that 300mm might be preferable.
  • Where there were stepped situations, it was believed that 600mm should be allowed local to those positions.
  • 1m was felt appropriate for flooding considerations.

• Containing any fire risk - 15 respondents to this question suggested that cavity barriers should be provided above this zone.

• Other elements - Apart from waterproofing and insulating materials, it was suggested by respondents that sub floor void ventilators and cavity trays within this zone should be similarly exempt.

Changing the performance requirements of the ban

77. In section 8 of the consultation we proposed updating the performance requirements of the ban in Regulation 6(3) and 7(2) to include reference to the updated standard BS EN 13501- 1:2018 and additional classifications A1fl, and A2fl-s1.

Floor testing

Question 12a - Do you agree with the proposed expansion of classifications required for materials used horizontally to include Class A2fl-s1 and Class A1fl?

• 181 (37%) of respondents said “agree”
• 64 (13%) said “disagree”
• 248 (50%) said “don’t know”

78. The majority of respondents (37%) said that they did not know whether they agreed with the proposed expansion of classifications required for materials used horizontally to include Class A2fl-s1 and Class A1fl. 37% of respondents agreed and 13% of respondents disagreed to this proposal.

Question 12b - If no, please explain why and provide evidence where possible.

79. The common themes and viewpoints from respondents who disagreed to this question are as follows:

• Limitation of A2fl product use - It was stated that such an allowance should only be applicable to balcony floor surfaces with solid construction below. It should not be allowed to any other horizontal position or element such as soffits or open floor decking. This is due to the flooring test being framed to an internal environment set to different fire attack/load circumstances and not measuring for burning droplets, which could be a risk from balconies or any other horizontal element.

• Appropriate testing of balcony floors - This question attracted comments on the best method for assessing the fire performance of balcony floors. Amongst the comments made, some expressed a view that they believed that waterproofing membrane in a ‘specified attachment’ has a more onerous status under ADB than that of membranes in external walls. This means that any normal waterproofing roof membrane product encapsulated in balcony construction cannot comply, as none currently on the market achieve A2-s1, d0 classification. Most of these waterproofing products are only normally tested as a component of a composite roof build up. Some respondents believed that the Broof(t4) test in conjunction with an A1 or A2 -s1, d0 soffit and edges would be an appropriate measure.

It was considered that further research is required to establish the extent of risk from balcony floors and what, if any controls, may be required.

Update of BS EN 13501-1

Question 13a - Do you agree that Regulations 7(2) and 6(3) should be amended to reference the current BS EN 13501-1 standard?

• 243 (49%) of respondents said “agree”
• 31 (6%) said “disagree”
• 221 (45%) said “don’t know”

80. 49% of respondents agreed that the regulations should be amended to reference the current BS EN 13501-1 standard. 45% of respondents said that they did not know and 6% disagreed to such amendment to the regulations.

Question 13b - If not, please explain why.

81. The common themes and viewpoints provided by those respondents who disagreed to the amendment included the following:

• Ensuring validity of existing tests - Some respondents who said they disagreed were concerned that certificates issued under the previous version of the standard would become invalid. Some of the respondents noted that where the regulation is prescriptive it then becomes necessary to legally secure the ongoing validity of testing conducted under previous versions. It was considered that such updating should not force an unnecessary process of reassessment of existing certification.
• System management - Some respondents commented that a system should be developed which flags the differences between the versions of standards and between different international standards, and explains how these standards should be applied. This would prevent the need to update references in legislation.

Some respondents highlighted that detailed references in regulations (such as ISBN numbers), can cause confusion as to what is valid and acceptable. This can create undue burdens on certification bodies, test houses and certificate holders. It was suggested that a flexible way of accommodating, and disseminating knowledge of, international differences and change to standards and/or test procedures, and how to apply them, needs to be developed.

Assessment of impacts

82. In section 9 of the consultation, we highlighted that changes to the ban could have a number of impacts which should be considered. These include the costs involved in meeting the required standard of combustibility in relation to the benefits of compliance. Any additional evidence gathered through the consultation would inform an impact assessment published after conclusion of the consultation.

Question 14a - Please provide any additional evidence on costs, risks and benefits which should be considered in an assessment of impacts of this consultation.

Question 14b - Are you aware of any particular equalities impacts for these proposals? How could any adverse impact be reduced and are there any ways we could better advance equality of opportunity or foster good relations between people who share a protected characteristic and those who do not? Please provide evidence to support your response.

The answers to this question ranged across both parts a) and b) of the question. Many answers were reinforcing some of the points made under previous questions. We have therefore presented the answers to both questions on a merged basis.

83. Effect on the use of timber and climate change considerations.

Respondents made the following points:

• All new regulations should be expected to align with climate change mitigation targets
• The environmental impacts of regulations should take account of a need to limit resource extraction and waste and look to renewable strategies
• Wherever possible passive measures to control overheating and other environmental effects on buildings should be preferred above mechanical solutions
• Extending the scope of the ban is likely to hinder achievement of environmental objectives as it impacts on the uptake if structural timber
• Any extension of the ban will not only increase that effect but also will run into medium height buildings that could utilise traditional timber frame construction
• An extensive research programme should be undertaken to establish the parameters enabling the safe use of structural timber.

84. Respondents made comments in respect of the following other aspects:

• Support for a ban of combustible materials in and on the external wall of buildings - A small number of respondents supported the proposal to reduce the height threshold as they believed that it would improve life safety in buildings and give confidence to residents and asset owners. Robust solutions were seen as securing long term housing benefits particularly for poor, vulnerable, and disadvantaged sectors of society.

• Construction impacts - It was considered that the current ban has created some uncertainty, wasting valuable time, and difficulty in achieving compliant solutions within the construction industry. These responses suggested that any widening of the ban, without any modifications, will have a further adverse impact on detailing, supply, sequencing, and time, which will as a result raise costs and reduce efficiency. These likely increase in costs were not quantified but a few respondents referred to the cost/time estimates previously quoted in the industry consultation.

• Business impacts - A number of business sectors reported that their business model, investment, and ongoing viability had been seriously impacted by the ban, and that any extension would exacerbate their problems. These sectors include the following:
  • timber and timber framing industry
  • blinds and shutter industry
  • glass and balconies
  • membrane manufacturers
  • roof waterproofing suppliers
  • insulation manufacturers

• Housing delivery - While overall supporting the proposals, some housing providers indicated that there would be an increased cost generated and an incumbent slowing of delivery of housing targets. It was also noted that the use of modern methods of construction and certain timber solutions can in some regards decrease delivery times and therefore reduce costs.

• Risk culture - Respondents raised concerns that any widening of the scope could trigger a wide range application of the requirements on existing buildings or new buildings beyond the current scope. Some respondents noted how the current ban that has had a negative effect on the valuation, insurability and marketability of buildings and homes. This has created a significant financial and wellbeing impact, of national concern, on many owners/occupiers.
  There was a viewpoint that disproportionate reactions to some risks have led to a breakdown of trust in the regulatory system and industry.

4. Government response

85. Our final policy approach considers the responses and evidence received to the consultation and advice received by the Building Regulations Advisory Committee (BRAC) and relevant industry bodies.

Buildings in scope of the ban

Changing the building types

86. The consultation proposed including hotels, hostels and boarding houses within the scope of the ban. This proposal was supported by 38% of consultation respondents (21% disagree, 41% don’t know), in addition to industry experts and stakeholders following announcement of the initial ban and during the review.

87. It is noted that these building types can be staffed overnight, have multiple routes of escape, signage and emergency lighting to assist evacuation, and higher level of detection and alarm systems than residential buildings. However, there is still a sleeping risk, and in the event of a serious fire, occupants are generally less familiar with their surroundings. This means that it can take longer to evacuate in the event of a fire, with a risk of a serious casualty incident.

88. Following consultation, hotels, hostels and boarding houses will be brought within scope of the current ban set at 18 metres. This means that that the external walls of these buildings will need to meet the same performance requirements (A2-s1, d0 or better).

Changing the height threshold

89. The ban currently applies to buildings with a top storey more than 18m above ground level. There have been calls to change this height threshold following fires in buildings just under 18m. We proposed lowering the height threshold of the ban, to include buildings with a storey at least 11 metres above ground level. A large research project was also proposed that would aim to improve our understanding of building risk in relation to height and other factors, in order to support an appropriate height threshold for the ban in the future.

90. The majority of consultation respondents disagreed (44%) with the proposal to reduce the height threshold to 11m. Respondents cited concern over the impact to industry by applying a blanket restriction to such a large number of buildings and restrictions on the use of structural timber, which is seen as having significant environmental benefits. Many stakeholders considered the ban as a “blunt instrument” that does not allow designers etc. to consider the risk of individual buildings. The ban applies to the full wall rather than just particular elements (e.g. cladding) which can cause unintended difficulties to industry in designing walls (e.g. including low-risk plastic components) and sourcing materials. This was proportionate for buildings above 18m in height. However, considering that the level of risk is to some extent related to the height of a building, a strict ban for buildings between 11 and 18m could be disproportionately restrictive.

91. We will therefore retain the ban at 18m and amend Approved Document B (ADB) to introduce new statutory guidance for buildings between 11m and 18m, setting limits on the combustibility of materials used in the wall which would reduce the inappropriate use of combustible materials in these buildings. The level of risk in buildings is relative to their height, and our approach is a proportionate response where the constraints on designers and developers increase with the height of a building.

92. As part of this approach we will reduce the height of buildings that must comply with the requirements at B4(1) of Schedule 1 when the whole building undergoes a material change of use from 15m to 11m.

93. The approach will enable designers and developers to apply their professional judgement to a degree, while still setting clear expectations. The ability for developers and designers to exercise judgement in the past has been criticised, but we consider that the increased level of risk is also mitigated by the 2020 changes to ADB making provisions for sprinklers and improved wayfinding signage for firefighters in all new blocks of flats more than 11m in height which provide significant life safety benefits.

94. Our approach will allow the continued use of structural timber in the external walls of residential buildings below 18m, if these materials are used safely in accordance with the requirements of the Building Regulations.

95. Buildings below 18m in height being designed currently must comply with Requirement B4 of the building regulations. The guidance to the building regulations (Approved Document B) states that designers should give due consideration to the materials they propose to use. Our approach will clarify this guidance by setting clear limitations on some of the materials used in the external wall.

96. In our consultation we proposed to carry out a research project regarding building risk to inform further review of the scope of the ban. We have now commissioned this research and it is underway. The research is currently scheduled to be completed later in 2022.

Metal composite materials (MCM)

97. In the consultation we proposed a complete ban of the use of metal composite materials (MCM) with an unmodified polyethylene core in and on the external walls of all buildings, regardless of height or use. This ban would prohibit such materials from being used on new buildings and buildings undergoing a refurbishment. This outright ban would apply to MCM with a polyethylene core, the type of cladding panels used on Grenfell Tower.

98. Research published by the Department in April 2020 demonstrated that this type of MCM poses such a significant fire risk that an outright ban on its use on any buildings, regardless of height or purpose, is justified.

99. There was strong support for this proposal in the consultation response. 48% of the consultation respondents supported the proposed ban of metal composite panels with a polyethylene core, 18% disagreed and 34% said they did not know.

100. We will therefore introduce a complete ban on the use of the type of metal composite material that was used on Grenfell Tower (metal composite material with an unmodified polyethylene core) in all buildings of any height.

Attachments

101. Solar shading products such as blinds, shutters, awnings, brise soleil, and similar products are not required to meet the performance requirements of the ban, however they must still comply with the functional requirements of the Building Regulations.

102. Solar shading devices can be an effective way of reducing heat gain in residences and other buildings. However, solar shading devices made of combustible materials, on the external walls of a building could create a path for fire to spread along the external walls of buildings.

103. The consultation proposed to extend the ban to include solar shading devices including, but not limited to, blinds and shutters. The proposal included an exemption for ground floor awnings and a definition for solar shading devices.

104. Non-combustible sun shading products are currently available on the market although these tend to be non-retractable and not made from flexible materials. Retractable awnings are often used at ground floor level for shop fronts or similar purposes. The risk posed by these is limited as they will not extend beyond the ground floor level and the external wall will need to meet the requirements of the ban.

105. Respondents highlighted that the ban prohibits the use of movable solar shading devices which are more efficient at reducing heat gains in buildings. Reasoning provided included that small components (such as bushes and bearings) which are necessary for solar shading devices to function cannot be made to achieve the required performance.

106. The responses to the consultation supported our proposals to include solar shading devices as a specified attachment (38% Agree and 24% disagree) and exempt ground floor awnings (39% Agree and 13% disagree). Therefore, in line with the application of the ban, the clearest way to ensure safety is to apply the requirements of the ban (Class A1 or A2-s1,d0) to the curtains and slats of solar shading devices, with an exemption for ground floor solar shading devices. This approach will ensure that smaller component allowing the operation of dynamic solar shading devices with a non-combustible curtain are not required to meet the performance requirements of the ban thus enabling the use of more efficient products while not compromising safety.

Exemptions

Cavity trays

107. In our consultation we proposed several changes to the list of exemptions in Regulation 7(3) including the temporary exemption of cavity trays in all forms of construction and the extension of the exemption of waterproofing and insulation materials.

108. Cavity trays are an essential wall component, installed in wall cavities to capture moisture that penetrates the outer face of the wall, preventing damp. Cavity trays are currently exempt only when used between walls constructed of two leaves of masonry. This type of construction is not common in modern high-rise buildings and industry has adapted by using stainless steel to produce cavity trays. However, industry has highlighted that this incurs excessive cost and there are issues with supply, installation and durability. Stainless steel is considered less durable than a plastic cavity tray and does not effectively prevent damp. There is increased potential for health and safety issues to arise if these products fail to adequately prevent moisture ingress and damp in buildings.

109. We are aware of some compliant non-combustible product on the market, however some industry stakeholders have expressed concerns over the installation of this product that may result in poor performance and issues of damp in buildings. We are aware that some developers have been unable to get a new homes warranty, making the homes unsaleable, due to concerns over the performance of non-combustible cavity trays.

110. The consultation proposed a temporary 18-month relaxation of the ban as it relates to cavity trays pursuant to Section 11 of the Building Act 1984. This would enable this matter to be resolved temporarily while maintaining industry momentum to develop adequate non-combustible alternatives. 68% of consultation respondents agreed with the proposal.

111. In the interest of health and safety, we will issue a type relaxation to allow industry to use cavity trays that do not achieve the strict performance requirements of the ban. We do not believe it is appropriate to permanently exempt cavity trays as it would hinder innovation in development of additional compliant products. It remains the clear intention of this government to ensure that non-combustible cavity trays are used in the external walls of building where they are already readily available and after the temporary exemption lapses.

Additional exemptions

112. We sought evidence-based views on additional exemptions, materials such as laminated glass, whether there are exemptions that should be withdrawn, and clarifications on exemptions such as roofing components. We will implement the following limited exemptions based on the collation of responses provided during the consultation:

Fibre optic cables in external walls

113. Consultation respondents raised concerns for the need to exempt fibre optic and similar non-electrical cables. The ban currently exempts electrical installations within the external wall construction such as wiring cables and sockets. However, this does not extend to fibre optics cable as these wires do not carry current. It is relatively common for fibre optic and similar cables to be routed through the external walls of buildings when retrofitting fibre optic cables. We will therefore proceed to exempt fibre optic cables alongside electrical installations.

Roofing components

114. The design of the junction between an external wall and a roof often requires that membranes used in the roof construction extend into the external wall with the aim of inhibiting the entry of water. Roofing materials passing through the external wall are exempted from the requirements of the ban.

115. Following the targeted survey and discussions with industry experts there appears to be uncertainty around the continuation of membranes used in a roof system when it is continued into the external wall. A narrow majority of the consultation respondents agreed (29% agreed and 25% disagreed) that further clarification was not required in guidance on the performance requirement for roofing membranes. However, several respondents considered that the question was worded in a confusing way. Considering that this clarification can easily be implemented in the guidance to the Building Regulations (Approved Document B) and will provide clarity to designers, we will provide this clarification on the application of the ban to roofing membranes through a clarification in the guidance to the building regulations.

Laminated glass

116. Laminated glass is made from two layers of glass with an organic vinyl interlayer up to 3mm thick used to bind the glass layers together. Glass (including laminated glass) is currently exempt from the ban only when included within a window frame.

117. For aesthetic reasons, laminated glass is often used in the construction of balconies. The ban on the use of laminated glass in balconies was raised in our review by industry stakeholders. We understand from manufacturers that there is currently no laminated glass available, for external use, able to achieve the appropriate classification (i.e. class A1 or A2-s1, d0) because of the interlayer.

118. In the consultation we sought comments and evidence on the use of laminated glass in and on external walls and attachments such as balconies. A small majority of respondents agreed with our proposal that laminated glass should continue to achieve Class A1 or A2-s1,d0 (28% Agree, 26% disagree). Some responses to the consultation highlighted a lack of evidence of laminated balustrades being involved in external fire spread with some analysis provided. The evidence provided in the responses to the consultation remained very limited and based on expert opinion, analysis of past incidents and limited to small scale tests (~300 by 300mm). The Department is currently undertaking some research on the use of laminated glass in balcony which will provide the necessary evidence to allow the Department to make an informed decision on whether laminated glass should be exempted or not.

119. We will therefore continue to require laminated glass to achieve Class A1 or A2-s1,d0 when used in a balcony.

Materials below ground level

120. Water proofing and insulation materials used in external wall construction below ground level are exempt from the requirements of the ban. This is because these products need to be water resistant and non-combustible materials are not typically water and moisture resistant.

121. The review raised a practical issue where there is a need for these materials to be continued above ground to prevent moisture penetrating the external walls, which could lead to issues with water ingress and damp. We do not believe that such a limited exemption would increase the risk of fire spread along the external wall.

122. In the consultation we asked for views on amending the current exemption for water proofing materials and insulation to include material used below and up to 250mm above ground level. 67% of consultation respondents agreed to this proposal and 5% disagreed. However, several respondents highlighted the fact that 250mm may not be enough to account for sloping sites. We will therefore exempt waterproofing and insulation materials up to 300mm from ground level from the ban.

Structural elements and engineering timber

123. The government has banned the use of combustible materials, including timber, in and on the external walls of new high-rise blocks of flats more than 18 metres in height as well as hospitals, care premises, and student accommodation meeting that height threshold.

124. We recognise the potential environmental benefits of timber construction where it can be used safely. The case for exempting structural timber from the requirements of the ban in the highest risk buildings has been made by some respondents. The government is not yet satisfied that the case is strong enough to justify an exemption at this time. The Department has commissioned research to look at the issue and how the use of modern methods of construction will inform the development of building regulations and any other necessary action.

125. The government is committed, through the England Tree Action Plan to increase the use of timber in construction and we are working across government to identify key opportunities for the safe growth of timber use in low-rise buildings.

Performance requirements

Floor testing

126. The A2 and A1 classifications apply to materials tested vertically as a wall. There are alternative classifications Class A2fl-s1 and A1fl that are available for materials tested horizontally as a floor. Several products used for balcony floors are currently only tested to A2fl-s1 or A1fl classification and as such do not meet the requirements of the ban. The classification A2fl-s1 and A1fl require materials to achieve similarly stringent requirements as Class A2-s1, d0 or A1.

127. In the consultation we proposed to exempt materials achieving the classifications required for materials used horizontally to include Class A2fl-s1 and Class A1 fl. A large majority of respondents agreed with our proposal (37% agreed and 13% disagreed). We will therefore allow the use of these additional classifications for materials tested horizontally (A1fl, and A2fl-s1) by exempting them in the Regulations

Update of BS EN 13501-1

128. In the consultation we proposed to update the performance requirements of the ban in Regulation 6(3) and 7(2) to include reference to the updated standard BS EN 13501- 1:2018 and additional classifications A1fl, and A2fl-s1.The standard referred to in the ban has been superseded and withdrawn. An updated version, BS EN 13501-1:2018, was published in January 2019 by the British Standards Institution. The updated version of the document does not impact classification A1 and A2-s1, d0. The main update of the document relates to classification F which is not used in the Building Regulations.

129. In the consultation we asked for views on amending the Building Regulations to reference the updated version of the standard to ensure that the most recent version of the British Standard is referenced in the regulations. A large majority of respondents (49%) agreed with our proposal and only 6% disagreed. We will therefore update the reference to this standard in the updated legislation.

5. Implementation

130. The amendments discussed above will be implemented through changes to the Building Regulations and building regulatory guidance (Approved Document B).

131. We consider that transitional provisions are necessary to allow the industry to adapt to the new requirements. The regulations will come into force 6 months after laying in line with previous changes to the building regulations. We consider that the sooner these changes can be made, the sooner we would expect to realise the life safety benefits in the buildings in scope of our changes.

132. The changes to the Building Regulations will come into force on 1 December 2022 and will apply unless an initial notice, building notice or full plans have been deposited before the day the regulations come into force, and work has either started or starts within a period of 6 months from that date. The changes to Approved Document B will take effect on the same day and the same transitional arrangements will apply. The direction relaxing the requirement related to cavity trays will take effect on 1 June 2022.