SDESmith Design Engineering

Governance

Health and safety

How SDE discharges its designer duties under CDM 2015, including risk elimination in design and the design risk register.

Designer duties under CDM 2015

The Construction (Design and Management) Regulations 2015 place specific duties on designers. SDE acts as a designer under those Regulations on every project.

Eliminate, reduce, control

The designer's duty is to eliminate foreseeable risk so far as is reasonably practicable, then to reduce what cannot be eliminated, and then to control what remains — in that order. Providing information about a hazard is the last step, not the first.

In building services design this most often applies to:

  • Maintenance access. Plant that cannot be reached safely will be reached unsafely. Access is a design decision taken at layout stage.
  • Working at height. Luminaire, terminal unit and valve positions determine how they are replaced for the life of the building.
  • Confined spaces. Plant rooms, ducts, tanks and voids.
  • Hazardous substances. Refrigerants, water treatment chemicals and any legacy material identified by survey.
  • Live working. Isolation and switching arrangements designed so that live working is not required.

The design risk register

Significant residual risks — those that are not obvious to a competent contractor — are recorded in a design risk register issued with the design information, identifying the hazard, who is exposed and what has been done about it.

The register records residual risk. It is not a substitute for eliminating risk, and a register listing hazards that could have been designed out is a failure of the process rather than evidence of it.

Cooperation

SDE cooperates with the principal designer, the principal contractor and the other designers, and provides information about its design in the form and at the time it is needed.

Last reviewed 29 July 2026.

QUESTIONS

Common questions

What are a designer’s duties under CDM 2015?

A designer must eliminate foreseeable risks to health and safety so far as is reasonably practicable, reduce risks that cannot be eliminated, and control those that remain. They must also provide information about significant residual risks and cooperate with the principal designer and other duty holders.