Designing Out the Unknown: Asbestos Information Duties for Principal Designers in 2026

As higher-risk building workfaces mature in 2026, the question is no longer whether asbestos belongs in the pre-construction conversation. It is whether the principal designer has the evidence to close that conversation before work starts. Under the Building Safety Act 2022, the principal designer for a higher-risk building has a coordinating role in building safety information. Under the Control of Asbestos Regulations 2012, the duty to manage asbestos in non-domestic premises remains with the dutyholder. Where refurbishment projects begin before existing asbestos-containing material information has been verified, those two obligations meet at a familiar point: an inherited register that is incomplete, caveated or simply out of date.

Two regimes, one evidence trail

Principal designer is not a single label. Under CDM 2015, the principal designer coordinates health and safety in pre-construction. Under the Building Safety Act 2022, the principal designer for a higher-risk building has duties connected with building safety information and coordination. Asbestos may not be the headline risk on every project, but it is a building safety and refurbishment risk that cannot be designed around on assumption.

The dutyholder remains responsible for managing asbestos in the premises. The principal designer does not take over that duty. What the principal designer can do is insist that the information supplied is fit for design, procurement and construction. That means asking for evidence, not just a PDF register. It means testing whether the survey scope matches the workscope. And it means recording where the information is insufficient, rather than allowing a design assumption to become a contractor instruction.

Why vague registers reach the workface

Management surveys are often commissioned for occupancy, not refurbishment. They may rely on presumed materials, exclude concealed voids, or record no access to risers, ceiling voids and plant rooms. A line that says presumed asbestos-containing material is not a finding that can be designed around without thought. Neither is a register that predates previous works. When drawings, registers and site conditions disagree, the design team needs a route to resolve the difference before the programme hardens.

Otherwise the contractor inherits the ambiguity, the workface stops, and the principal designer is asked why the information gap was not closed earlier. The answer cannot be that the register was received and filed. In 2026, the more defensible answer is that the register was tested, its limitations were understood, and the necessary survey or access work was commissioned before design freeze.

A pre-construction asbestos checklist

Principal designers should not attempt to duplicate the dutyholder or the asbestos surveyor. They should, however, apply a structured challenge to the information on which design and procurement depend.

1. Define the workface and its interfaces. Identify the areas to be altered, the routes for services and the zones where disturbance could occur. A register that covers the building is not automatically a register that covers the project.

2. Test the provenance of the register. Establish when it was produced, by whom, for what purpose and against which drawings. Check whether it is a management survey, refurbishment survey or demolition survey. Confirm that sample references and laboratory certificates are available where relied upon.

3. Map exclusions and unopened voids. List every no-access area, riser, ceiling void, floor void and plant space that the survey did not open. Ask whether the works will require access to those spaces. If so, the information gap is a pre-construction action, not a contractor risk.

4. Commission refurbishment and demolition survey before design freeze. Where the works will disturb the fabric, a management survey is unlikely to be sufficient. The refurbishment and demolition survey should be scoped to the works and completed before design decisions lock in a route, fixing or service penetration.

5. Interrogate assumptions and caveats. Presumed and strongly presumed materials require a planned response. Caveats about inaccessible areas, limited sampling or previous refurbishment should be read as open items. The principal designer should record who is closing each item and by when.

6. Check competence and licence status. Confirm that surveyors and contractors have the relevant competence for the task. Where licensed work is foreseeable, check licence status early. Do not leave licence checks to the week before mobilisation.

7. Record design decisions and change control. Note where asbestos information has influenced the design, and where design changes could alter the disturbance risk. A later change to a service route or fixing detail can invalidate the assumptions behind the survey scope.

8. Plan the unknown-material response. The pre-construction information should state what happens if a material not recorded in the register is encountered. Stop, isolate, record and seek advice should be built into the construction phase plan, not improvised on site.

9. Hand over a coherent information set. The principal designer should ensure the pre-construction information pack identifies the asbestos evidence, its limitations and the actions required. The contractor should be able to see the difference between verified information, presumed materials and areas of no access.

The dutyholder's side of the bargain

The dutyholder must provide information and access, and should not assume that the principal designer can resolve missing asbestos records by design alone. A principal designer who asks for evidence is supporting the dutyholder, not challenging their authority. If records are absent, the dutyholder should commission the necessary survey work or provide a written rationale for the alternative approach.

Equally, contractors should not accept a vague register as a transfer of risk. A tender that prices on an unverified register may be cheap only because the unknown has been ignored. The principal designer can reduce that risk by making the information gap visible before procurement.

Information as a design control

By 2026, the principal designer's asbestos burden is not a request to become the asbestos surveyor. It is a duty to test the information on which design relies. A verified, current and scope-matched evidence set is a design control. It protects the programme, supports the dutyholder and gives contractors a workface they can plan around. The alternative is familiar: an unopened void, a caveated register and a stop notice that arrives after the design has already been built.