At the end of April we told you about the key things you need to know about the changes introduced in the Building Safety Act 2022.

The secondary legislation that will enable a number of those provisions will be put in place over the next 12-18 months, but in the meantime, the Government has just published its response to the results of a consultation on the ambit of building safety[1] which took place between January and May 2020.

This consultation proposed changes to requirements of the Building Regulations (introduced in December 2018 by way of the Building (Amendment) Regulations 2018) which in effect banned 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:

There were 854 respondents to the consultation comprising of individuals and organisation representatives with, it appears, limited supporting evidence provided to either support or reject the proposed changes.

Having had two years to review these responses, the Government has concluded its deliberations and has introduced the Building etc. (Amendment) (England) Regulations 2022[2] (the Amendments), which come into force on 1 December 2022.

The summary of changes are as follows:

Buildings in scope of the ban – changing the building types

The consultation proposed including hotels, hostels and boarding houses within the scope of the ban. This proposal was supported by 38% of respondents with the sleeping and evacuation risks being acknowledged. And accordingly, hotels, hostels and boarding houses will be brought within scope of the current ban set at 18 metres. This means the external walls of these buildings will need to meet the same performance requirements (A2-s1, d0 or better) as the higher risk buildings already covered by the ban e.g. high rise residential and student accommodation.

Changing the height threshold

The ban currently applies to buildings with a top storey more than 18 metres above ground level. There have been calls to change this height threshold following fires in buildings just under 18 metres. The consultation proposed lowering the height threshold of the ban, to include buildings with a storey at least 11 metres above ground level.

The majority (44%) of respondents disagreed with the proposal to reduce the height threshold to 11 metres. 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. 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 is considered proportionate for buildings above 18 metres 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 18 metres could be disproportionately restrictive.

The ban is therefore being retained at 18 metres but the guidance in Approved Document B (ADB) will be amended to introduce new statutory guidance for buildings between 11 and 18 metres, setting limits on the combustibility of materials used in the wall which will reduce the inappropriate use of combustible materials in these buildings. The level of risk in buildings is relative to their height, and the Government considers this approach is a proportionate response where the constraints on designers and developers increase with the height of a building.

However, the Amendments do reduce the height of buildings that must comply with the requirements when the whole building undergoes a material change of use from 15 to 11 metres e.g. a change from use as offices to a hotel or residential.

It is considered that this 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 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 11 metres in height which provide significant life safety benefits.

The approach therefore permits the continued use of structural timber in the external walls of residential buildings below 18 metres, if these materials are used safely in accordance with the requirements of the Building Regulations.

Metal composite materials

The consultation 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 will 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.

There was strong support for this proposal in the consultation response. 48% of the respondents supported the proposed ban.

The Amendments will therefore introduce a complete ban on the use of MCM with a polyethylene core in all buildings of any height.

Attachments to buildings

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.

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.

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.

The responses to the consultation supported the proposals to include solar shading devices as a specified attachment (38% agree) and exempt ground floor awnings (39% agree).

The Amendments will apply the requirements of the ban (Class A1 or A2-s1,d0) to the curtains and slats of solar shading devices (as opposed to the whole of the device), with an exemption for ground floor solar shading devices. This approach aims to ensure that smaller components 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

The consultation proposed several changes to the list of exemptions in Regulation 7(3) including the temporary exemption of cavity trays in all forms of construction, routing of fibre optic cables through external walls, the extension of the exemption of waterproofing and insulation materials and the use of laminated glass in balconies.

The responses relating to these changes were generally more mixed with a significant level of "don't knows". Further research is being undertaken in a number of areas, but for present purposes the Amendments 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. It will also provide an 18-month temporary relaxation for cavity trays in all forms of construction. The ban on the use of laminated glass in balconies will remain pending the outcome of further research.

Clarifications on some issues will also be included in the amendments to ADB.

Performance Requirements

Materials used in Balcony construction

The consultation proposed to extend the exemption relating to testing classifications for materials used horizontally in balcony construction to include Class A2fl-s1 and Class A1 fl, in addition to the exemption applying to classifications for vertical testing. 37% of respondents agreed with the proposal.

The Amendments therefore 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).

Update of BS EN 13501-1

In the consultation the Government 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. 49% of respondents agreed and the Amendments update the reference to this standard.

So what next?

Some of the Amendments are not unexpected e.g. the extension of the buildings in the scope of the ban to included hotels and such like.

What is a little more surprising is the rather ambiguous outcome on the reduction to the height threshold. What we have ended up with is no reduction to 11 metres, but new statutory guidance applicable to buildings between 11 and 18 metres. The Hackitt report was concerned that the existing package of regulations and guidance could be ambiguous and inconsistent and led to there being misunderstandings as to whether judgements made by designers by reference to the guidance met the Regulations, and this is therefore likely to continue on buildings between 11 and 18 metres.

Further, these provisions only relate to buildings in England – Scotland has taken a different approach choosing to adopt 11 metres as the threshold for limiting the use of combustible cladding materials.

The implications of the Building Safety Act 2022 are still being worked through but as such has been the case since the first draft of the Bill, the devil really is in the detail with different time limits, height limits and the differing scope of provisions throughout the 230 pages of the Act.

The Amendments 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 Amendments come into force, and work has either started or starts within a period of six 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 took effect on 1 June 2022.