It's only a two-day job. Do I need a Principal Designer?

The short answer

Look at the contractors, not just the calendar.

Under the Construction (Design and Management) Regulations 2015 (CDM 2015), a Principal Designer is required for a project involving, or where it is reasonably foreseeable that it will involve, more than one contractor. This is not limited to larger construction projects and there is no general one- or two-day exemption.

The Principal Designer must be a designer with control over the pre-construction phase and the appropriate skills, knowledge, experience and organisational capability for the work. On commercial projects, the client must make the appointment in writing as soon as practicable and before construction starts.

What about a small refurbishment?

Consider a small commercial project involving fire door replacements and redecorating. If one contractor carries out one package and a separate decorating contractor follows, the project may still involve more than one contractor, even if the work is completed within two days.

The same principle can apply to retail alterations, minor hospitality refurbishments, office modifications and landlord remedial works. The precise position depends on how the work and contractor appointments are organised.

One contractor or several?

• One contractor for the whole project: a CDM Principal Designer and Principal Contractor appointment is not triggered by the multi-contractor rule. Other CDM duties still apply, including the need for a suitable Construction Phase Plan.
• More than one contractor, or more than one reasonably foreseeable: the Principal Designer and Principal Contractor roles are required, subject to the domestic-client rules below.
• Different contractors on different days: the fact that contractors never overlap on site does not, by itself, remove the appointment requirement.

Are domestic projects different?

CDM 2015 also applies to domestic projects such as extensions and refurbishments. Where more than one contractor is involved, the Principal Designer role is still relevant. However, if a domestic client does not formally appoint one, the designer in control of the pre-construction phase takes on that role under regulation 7. Domestic-client duties normally pass to the Principal Contractor, unless other permitted arrangements are made.

That is different from the position for commercial clients, who have explicit duties to make the appropriate written appointments. For either type of project, arrangements should be understood and agreed early rather than assumed after works have started.

What about F10 notification?

The requirement to notify a project to the HSE using an F10 is separate from whether a Principal Designer is required. Notification generally applies where construction work is scheduled to last longer than 30 working days with more than 20 people on site simultaneously at any point, or where it exceeds 500 person-days.

A two-day project will ordinarily not reach those notification thresholds, but that does not create an exemption from the Principal Designer appointment provisions.

How can Altaris help?

Altaris Advisory provides independent CDM 2015 Principal Designer services for commercial and residential construction. We can discuss the project arrangements, agree an appropriate scope and provide a tailored quotation through our online Quote Portal.

Common questions

Further guidance

This is general guidance, not a determination of your particular project. For the legal duties and detailed guidance see the HSE Principal Designer guidance, the HSE domestic client guidance, and the CDM 2015 Regulations.