A design-build firm working in mid-rise residential and mixed-use construction receives its professional liability renewal package. The carrier has added a new application requirement: a documented legacy review of all projects completed in the past ten years that involved concrete transfer slabs, post-tensioned flat plate systems, or structural elements with punching shear connections. Renewal is contingent on the review. The firm has six weeks to produce documentation it was not expecting to need.
This is not an isolated scenario. Beginning in mid-2026, a significant number of professional liability carriers have moved to treat concrete transfer slab and structural punching shear exposure as a heightened underwriting category, requiring affirmative documentation of past projects before writing new or renewal terms for design-build firms with this exposure profile. The shift is a direct response to a pattern of structural failures and near-failures in post-2010 construction that have generated large professional liability claims and drawn intense scrutiny from structural engineers, building officials, and the insurance industry simultaneously.
What Is Driving the Carrier Concern
Concrete transfer slabs are structural elements that redirect gravity loads from upper-story columns to a different column grid below. They are commonly used in mixed-use buildings where residential floors have a different structural layout from the retail, parking, or commercial spaces below. Punching shear is a failure mode that occurs when a concentrated load, such as a column bearing on a flat-plate slab, causes the slab to fail around the column rather than through conventional bending. Both systems require precise engineering, detailed connection design, and rigorous quality control during concrete placement and curing.
The professional liability exposure arises from two primary sources. First, errors in transfer slab geometry, post-tensioning layouts, or shear reinforcement detailing can create structural deficiencies that may not be immediately visible but can contribute to progressive loading concerns over time. Second, the complexity of these systems can allow design errors to carry through construction without detection, particularly in design-build projects where the same entity is responsible for both the design and the construction quality control that might otherwise identify a detailing issue before the concrete is placed.
Cases involving distress in concrete transfer slabs, including post-construction investigations that identified inadequate punching shear reinforcement in completed and occupied buildings, have resulted in professional liability claims and potential claims. These cases have also drawn attention to the broader risk associated with this type of structural system. The consequences of failure can be significant, defects may remain undetected for years, and the design-build delivery model can place both design responsibility and construction quality control with the same entity.
What a Legacy Project Review Requires
The legacy review that carriers are now requiring is not a brief questionnaire. It is a documented technical analysis of the firm’s past projects that involved the relevant structural systems. What carriers expect to see varies by underwriter, but the core elements are consistent across the market.
Project inventory with structural system identification: A complete list of projects completed during the specified lookback period, typically five to ten years, should identify which projects involved concrete transfer slabs, post-tensioned flat-plate systems, punching shear connections, or similar structural configurations. Firms that cannot produce this inventory may face an immediate underwriting concern. If a firm does not know which past projects involved these systems, it cannot demonstrate that those projects have been identified and reviewed.
Design documentation and peer review records: For projects with relevant structural exposures, carriers may ask for evidence that the structural design was peer-reviewed by a qualified structural engineer who was independent of the design team. Peer review documentation, particularly for transfer slab geometry and punching shear reinforcement details, demonstrates that an independent professional evaluated critical design decisions before construction. Firms that routinely conduct peer reviews for complex structural systems and maintain documentation of those reviews can provide stronger evidence of their quality control processes than firms that rely solely on internal review.
Post-construction status of relevant projects: Carriers want to know whether any of the identified projects have generated complaints, warranty claims, structural investigations, or construction defect notices since completion. A firm that can affirmatively document that its completed concrete transfer slab projects have not generated any structural concerns is providing the most direct evidence available that its past design work has performed as intended. A firm that has received post-construction structural inquiries on relevant projects, even informal ones, needs to address those proactively in the underwriting submission rather than allow the carrier to discover them during the application review.
Current quality control protocols for ongoing and future projects: Beyond the legacy review, carriers are evaluating what the firm does differently going forward. Updated specifications for punching shear reinforcement, mandatory peer review triggers for transfer slab projects, enhanced quality control during concrete placement for critical structural elements, and contractual provisions requiring special inspection of relevant connections are all viewed favorably. Firms that can document that the underwriting concern has been reflected in their current practice are demonstrating risk management maturity that translates directly into underwriting treatment.

What Firms Without Documentation Should Expect
A design-build firm with limited records for completed structural projects should address that gap before its professional liability renewal. Start by identifying projects involving concrete transfer slabs or punching shear design, then locate the available calculations, drawings, design changes, quality control records and peer review reports. Discuss missing materials with the firm’s design professionals and insurance adviser so the renewal submission accurately describes the work performed and the records available.
Carriers may ask additional questions about complex structural work. The terms offered will depend on the firm, its projects and the insurer; an exclusion, higher retention or demand for an independent review should not be presented as a standard 2026 underwriting requirement without evidence from the carrier. If an independent engineering review is appropriate, define its scope with qualified professionals before commissioning it. The American Society of Civil Engineers’ policy on peer review explains the role of an independent evaluation alongside a project’s normal quality control. Peer review
The coverage review should also examine how the policy treats completed work, prior acts, exclusions and the design services performed by subcontractors. The Design-Build Institute of America’s sample insurance requirements illustrate why professional liability coverage needs to match the scope of services under the contract. store.dbia.org
Tooher-Ferraris helps design-build contractors review professional liability coverage in the context of their project history and broader commercial insurance program. Explore its specialty programs or contact the team to discuss an upcoming renewal.
Frequently Asked Questions
Which design-build firms are affected by the concrete transfer slab underwriting shift?
The shift primarily affects design-build firms that have completed projects involving concrete transfer slabs, post-tensioned flat-plate systems with punching shear connections, or similar structural configurations in mixed-use, residential, or commercial construction. Firms that work exclusively with structural systems that do not involve these elements, such as wood-frame construction, steel-frame construction without concrete transfer elements, or masonry, are generally not subject to this specific underwriting concern.
What is a punching shear failure and why does it concern professional liability carriers?
Punching shear is a structural failure mode in which a concentrated load, typically a column bearing on a flat-plate concrete slab, causes the slab to fail around the column rather than through conventional bending. The failure can occur suddenly and may have severe consequences in occupied buildings. Professional liability carriers focus on punching shear exposure because failures may be linked to design detailing errors or inadequate shear reinforcement specifications, creating potential professional liability claims against the engineers and design-build firms responsible for the design.
What should my firm do if we have concrete transfer slab projects in our history and our PL renewal is approaching?
Begin the legacy review process well before your renewal date, ideally four to six months in advance. Compile a project inventory that identifies relevant structural systems. Gather peer review documentation for the projects with highest structural complexity. Confirm the post-construction status of completed projects and document any structural inquiries or concerns that have been received and how they were resolved. Work with your insurance broker to prepare a proactive underwriting narrative that presents this information affirmatively rather than allowing the carrier to discover gaps during application review.








