For designers

CDM responsibilities for architects on domestic projects

Short answer

On a domestic project a design practice carries two separate things. First, its own designer duties under regulation 9, which apply on every project and cannot be transferred. Second, and only where the client has appointed nobody, the principal designer role itself, which regulation 7(2) gives to the designer in control of the pre-construction phase. The practical consequence is that domestic work carries more CDM exposure for a practice than commercial work, not less.

Why domestic work is the higher exposure

It runs against the intuition, so it is worth stating plainly. On a commercial project, if the client appoints nobody, regulation 5(3) leaves the principal designer duties with the client. The designer is not dragged in. On a domestic project regulation 7(3) switches that off and regulation 7(2) puts the role on the designer in control of the pre-construction phase instead.

So the projects most likely to have no appointment, small domestic jobs where nobody has a professional team telling them to make one, are also the projects where the unappointed role lands on the design practice.

The checklist for a domestic project

  1. Establish whether the client knows their duties

    Regulation 9(1) makes this a precondition of starting design work, and it is also the moment to raise the appointment.

  2. Establish whether more than one contractor is foreseeable

    Almost always yes on a domestic job. That is what triggers the regulation 5 appointments.

  3. Get the appointment made, in writing

    Either you, priced and resourced, or a specialist appointed by the client. Written, before the construction phase begins.

  4. Do your regulation 9 work and record it

    Design out what you can, and write down the risks that remain and why they remain. A short design risk register beside the drawings is usually enough.

  5. Hand the residual risk information over

    To the principal designer if it is not you, for the pre-construction information and the health and safety file.

  6. Keep going after planning

    Regulation 9 applies to modifying designs too. Changes during construction are design work.

What to tell a domestic client, in one paragraph

Your project will involve more than one contractor, so the Construction (Design and Management) Regulations 2015 require you to appoint a principal designer and a principal contractor in writing before work starts. Our fee does not include the principal designer role. If no appointment is made, the regulations place the role on the designer in control of the pre-construction phase, which would be us, without the resources or fee to carry it. We would rather it went to a specialist, and we can get you a fixed price for that in a couple of minutes.

A model paragraph. Adapt it to your own terms; it is not legal advice.

Where practices most often come unstuck

Written by James Nicholson, BSc (Hons) Architectural TechnologyLast reviewed 28 August 2026How we write this

Sources

  1. CDM 2015, regulation 5: appointment of the principal designer and the principal contractor legislation.gov.uk
  2. CDM 2015, regulation 7: application to domestic clients legislation.gov.uk
  3. CDM 2015, regulation 9: duties of designers legislation.gov.uk
  4. HSE: designers, roles and responsibilities hse.gov.uk
  5. HSE: domestic clients, roles and responsibilities hse.gov.uk

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