The Building Safety Regulator has issued an information note for principal accountable persons and building owners about potential structural risks associated with reinforced concrete transfer slabs. Published on 19 December 2025 and applying to England, the notice aims to support proportionate risk management while further technical work proceeds.
A transfer slab is a floor arrangement where a column bears on a slab without a supporting column directly below, allowing loads to be passed to columns on a different grid. This approach is common in mixed‑use development and has been used in the UK for more than 25 years, though the regulator stresses that not all such buildings will be affected.
The specific concern is punching shear in transfer slabs, where concentrated load can cause a column to punch through a reinforced concrete slab, leading to localised collapse. The regulator states it is not aware of any building collapse in the UK arising from this mechanism. The Institution of Structural Engineers published new guidance on the design of transfer slabs in November 2024 to strengthen practice for new projects.
The information note emphasises proportionality. The presence of a transfer slab alone is not a reason to decant residents. Where there are visible signs of distress, such as cracking, or specific concerns about a building’s condition or design, owners should seek professional advice. Further advice will follow and owners are asked to remain alert to updates.
Accountable persons should reflect any transfer slab issues in their assessment and management of structural risk and maintain the golden thread of building information. Government guidance sets out these duties for higher‑risk residential buildings, including the requirement to keep residents informed through a resident engagement strategy.
Where a higher‑risk building is concerned-defined in guidance as at least 18 metres or seven storeys with two or more residential units-the principal accountable person must operate a single mandatory occurrence reporting system. Safety occurrences involving structural failure, including discovery of structural defects that could affect load‑bearing performance, must be notified as soon as possible and reported within 10 calendar days.
In practical terms, owners should establish whether a transfer slab is present in their building and, if there are signs of distress or specific design concerns, obtain professional advice. Any findings, interim measures and decisions should be recorded in the golden thread and reflected in safety case material and building assessment certificate submissions when required.
For projects in design or under construction, dutyholders should ensure that change control captures any alterations affecting transfer slabs. Notifiable and major changes must be escalated to the regulator before implementation in line with published guidance on controlled changes for higher‑risk building projects.
The regulator has commissioned independent research and consulted its Building Advisory Committee to establish the level of risk associated with transfer slabs and how it can be managed proportionately across the existing stock. Updates will be issued through BSR bulletins and the campaign website; owners should monitor these channels for further instructions.