Transfer Slabs, Punching Shear and Professional Liability: The Next Significant Risk for UK Construction Claims and Insurance?

Transfer Slabs, Punching Shear and Professional Liability: The Next Significant Risk for UK Construction Claims and Insurance?

Concerns regarding punching shear in transfer slabs are increasingly relevant to insurers, construction professionals and those involved in professional liability and construction claims.

Since the RAAC ‘crisis’ emerged in 2024, the evacuation of buildings caused by cracked concrete has felt like a regular feature in our newsfeeds. However, when the residents of the Wotton Court in East London’s Virginia Quay development were evacuated from their properties on 10 May 2025, the cracked concrete was symptomatic of an entirely different risk: punching shear failure in a concrete transfer slab.

The Institution of Structural Engineers ("IStructE") has since issued new industry-wide guidance and the Building Safety Regulator (“BSR”) has published a notice highlighting the risks posed by this common design feature to which construction professionals and insurers alike have become increasingly alert due to the potential for significant liabilities.

Concerns regarding punching shear in transfer slabs are increasingly relevant to insurers, construction professionals and those involved in professional liability and construction claims.

Transferring structural loads in mixed-use developments

Where a building’s load is supported on columns that, instead of passing in a straight vertical line, have a different layout above and below a particular level, it is necessary to transfer those loads laterally to the lower level columns. This is a common feature in mixed-use buildings with commercial space at ground level and residential apartments above,

One solution to this design requirement is a ‘transfer slab’ - a thick, reinforced concrete floor that is strong enough to support the loads as they pass from one arrangement of columns into another.

IStructE Guidance and Punching Shear Failure Risks

Transfer slabs have been widely used in the UK for over 25 years. However, in November 2024, IStructE, published the first industry-wide design guidance addressing what it described as a ‘gap in knowledge’ surrounding them.

Following publication of the IStructE guidance, in December 2025, the Building Safety Regulator (“BSR”) made an announcement which highlighted potential risks due to questions over the adequacy of historic design and concerns over ‘punching shear failure’ where a high concentration of load causes a column to punch through a concrete transfer slab.

Professional Liability and the Building Safety Act 30-Year Limitation Period

Concerns over claims from the historic design of transfer slabs is a particular concern in England due to the Defective Premises Act 1972 (the “DPA”) which gives owners and those with a beneficial interest in residential dwellings the right to claim against those involved in the property’s design and construction.

While the DPA has been around for over 50 years, it has risen to renewed prominence in the wake of the Building Safety Act 2022 which retrospectively extended the limitation period for DPA claims to either 30 or 15 years (depending on whether the building was completed prior to June 2022.

As transfer slabs have only been in use for around the last 25 years according to the BSR, the Building Safety Act effectively brought every mixed use residential/commercial development using transfer slabs into the realm of potential claims.

The extension of limitation periods has increased the potential for construction claims arising from transfer slab design and alleged punching shear risks, creating significant professional liability exposure for those involved in the design and construction process.

While similar designs will have been used in Scotland over that period, the absence of an equivalent to the DPA means the residents of those properties rarely have a direct cause of action against those who designed and built them and, even where they might, many claims are likely to have time barred.

Practical Implications: Transfer Slabs, Punching Shear and Potential Construction Claims in Practice

From a construction claims and professional liability perspective, the significance of transfer slabs and punching shear concerns extends beyond structural engineers to insurers, surveyors, developers and other construction professionals.

The BSR notes that there have been no known building collapses caused by a punching shear failure in the UK. Nevertheless, there have been several high-profile examples of the issue potentially having significant impact.

In December 2025 the First-tier Tribunal(Property Chamber) issued a remediation order (“RO”) for the Virginia Quay property that had been evacuated in May that year citing the identification of cracks in the pillars and balconies. In making this order, the Tribunal ordered a "full building-wide structural engineering survey" to be carried out. Other properties, such as four blocks at Stratford Halo in London, have been evacuated due to reportedly similar issues.

Also in December 2025, the IStructE published a further statement highlighting the fact transfer slabs are included in the Building Safety Act mandated structural safety assessments of Higher Risk Buildings in England and Wales. We have been unable to find any reliable figures on how many buildings have failed that assessment but anecdotally brokers and claims handlers are reporting numerous notifications, albeit so far it appears the number of claims has been relatively limited.

The consequences of this are not limited to those who designed and constructed the properties. The Royal Institution of Chartered Surveyors (RICS) has issued a Practice Alert stressing that members must stay within their area of competence and that if they identify a building with a transfer slab then a suitable expert structural engineer will be required to carry out more in-depth analysis. This could have a significant impact on the prospects of selling or remortgaging residential units in such developments.

Conclusion: Transfer Slabs, Professional Liability and Future Construction Claims

Whether the issue ultimately produces a large volume of construction claims remains to be seen. However, transfer slabs and punching shear risks have already become important considerations in professional liability, professional indemnity insurance and building safety assessments.

IStructE has stated it is working on a guide on the assessment of existing transfer slabs and the BSR states it "commissioned independent research in late 2024 to establish the level of structural risk associated with transfer slabs". Only time will tell the full impact of these issues but the potential financial consequences of even a handful of claims could be significant for construction professionals and their insurers, many of which are likely to have significant exposure to this type of construction method.

In light of risks posed and the importance of maintaining professional duties, professionals should remain alert to developments. If you are a construction professional, surveyor or work in the insurance industry, and would like to discuss these issues further please do get in touch with our professional indemnity lawyers, or your usual Brodies contact.