The control of works to a ceiling serving an Independent Section that is also part of the compartmentation to the HRB above

Guidance

Is work to a ceiling building work?

Building work is defined in Regulation 3 Building Regulations 2010 work to an existing ceiling would be material if at any stage it affects:

• Part A (structure)
• Paragraph B1 (means of warning and escape)
• Paragraph B3 (internal fire spread—structure)
• Paragraph B4 (external fire spread)
• Paragraph B5 (access and facilities for the fire service)
• Part M (access to and use of buildings)
• Part T (Toilet Accommodation)

If the compartmentation has been found to be defective, then the proposals to remediate would be a Material Alteration as they would affect Paragraph B3 and possibly Part A.

Who would control this building work?

It is Sweco’s view that although the works are being undertaken from within the demise of the Independent Section the compartmentation serves the HRB. Therefore, the work to the ceiling would be controlled by The Building Safety Regulator, and a “Gateway” application would have to be made.

Regulation 12 The Building (Higher-Risk Buildings Procedures) (England) Regulations 2023 helps us when looking at work to existing HRBs as it defines work that is Category A work. Regulation 12(6)(g) describes “work which affects the passive fire safety measures in the higher-risk building”.

Regulation 2 of The Building (Higher-Risk Buildings Procedures) (England) Regulations 2023 defines passive fire safety measures to include cavity barriers, fire door sets, duct dampers, fire shutters and other fire separating elements;

If the works are purely structural and only impact on Part A, then it would be considered Category B work.

Approach to consideration of these matters by RBI

It is essential that we are inquisitive when the approach to compliance is presented to us. It is essential that we are satisfied with our understanding of the approach before we corroborate it. The following list is typical of the approach to fire precautions, but not exhaustive. Each case must be considered on its own merits including any structural implications of the proposal on the compartmentation (if in doubt consult a Technical Director)

The control of works to a ceiling serving an Independent Section that is also part of the compartmentation to the HRB above – Guidance Note 19.

1. Ask if adequate compartmentation fire resistance is achieved by existing construction during design phase?

2. If duty Holders confirm satisfactory this can be accepted

3. If you become aware, during the design or construction phase, that this is not the case, you must inform the Duty Holders that building works should be undertaken to rectify the deficiency and these building works would be under the control of BSR

4. This advice should be copied to the Accountable Person and we should suggest that until rectified, the deficiency should be noted in their Building Safety Plan with appropriate mitigation

5. The Principal Designer and Principal Contractor, under CDM Regulations, should also be made aware so they can make suitable provision under their duties

Proposed New Build HRBs –  intended to be divided into a number of Independent Sections on Completion

Given the difficulties inherent in having associated works being controlled by two separate bodies, it may be prudent for Duty Holders to consider how the design of compartmentation between proposed Independent Sections in a new building could prevent future work within the Independent Section requiring a “Gateway” application.

A robust construction that is unlikely to deteriorate in terms of fire performance through age or damage would reduce the likelihood of remediation work having to be undertaken that would affect paragraph B3. It should be noted that these measures would not prevent any subsequently proposed penetrations to the compartmentation, serving an HRB, requiring a “Gateway” application.

Also, consideration of the post-completion fixing to the underside of the floor is advisable. It should be a matter of record of what additional loads the floor structure is designed to accommodate. The record should also reference how and where fixings can be made into the structure so as not to affect its structural performance and fire resistance. This information would form part of the Golden Thread.

Extending the principle to other walls and floors that are separating Independent Sections from an HRB

The principles above would apply to any element separating an Independent Section from an HRB.  In each case, careful consideration would need to be made, and documented, of the works within the scope, of the proposed Material Alteration, to establish if any would be classified as building work that must be controlled by the BSR.

Further reference can be made to Sweco Guidance notes:

Independent Sections

Interpretation of the ‘no worse’ rule Building Regulation 4(3)