When Does A Principal Designer Need To Be Appointed? header image

18th February, 2020

When Does A Principal Designer Need To Be Appointed?

A principal designer needs to be appointed on all construction projects involving more than one contractor. Including subcontractors. But even though this role was introduced back in 2015, as the newest CDM duty holder, the principal designer role still gets a lot of questions.

When is a principal designer needed? When do they need to be appointed? And what is a project with more than one contractor? What about domestic projects?

In this post, we will answer all of the appointment questions surrounding the principal designer role.

The principal designer role is required under the Construction (Design & Management) Regulations (CDM). This set of regulations apply to all construction work and are a legal requirement. Every construction project must comply with CDM, and that includes appointing the necessary CDM duty holders.

Under CDM, a principal designer must be appointed:

  • By the client
  • On all construction projects with more than one contractor
  • Including domestic projects
  • At the start of the project

5.—(1) Where there is more than one contractor, or if it is reasonably foreseeable that more than one contractor will be working on a project at any time, the client must appoint in writing

  1. a designer with control over the pre-construction phase as principal designer;

A principal designer needs to be appointed on ALL construction projects with more than one contractor. You can see we have placed some emphasis on the word ALL.

Previously, duty holder appointments such as the principal contractor (and the now removed role of CDM coordinator) did not need to be made on domestic projects. Domestic projects are construction work carried out on your own home, or that of a family member, not connected with a business.

And before 2015, these additional appointments did not need to be made on none-notifiable projects (projects that didn't need to be notified to the HSE).

But, in 2015, this changed.

The principal designer does need to be appointed on both:

  • Domestic projects
  • Non-notifiable projects

And, as a side note, so does the principal contractor role.

cdm domestic
The principal designer is required on both domestic and commercial projects

As you can see, the appointment of a principal designer is often required, and not just on bigger commercial projects. In fact, on most construction projects, big and small.

If you think about it, most construction projects involve more than one contractor. Even if you only book in a single contractor for the work, they will often use subcontractors for particular activities on the job. Even if it's only a scaffolder for access or an electrician for a day. If additional contractors will be used at any time then a principal designer and a principal contractor are needed.

With both the principal roles (principal designer and principal contractor), there can only be one at any time. The principal designer is the designer in overall control of the pre-construction phase (everything before work starts on site, e.g. when you are planning the work). The reason why there can only be one principal designer on a project, it that they are the main point of contact for other duty holders (designers and contractors). And they coordinate all of the information at this stage.

So, you may have multiple designers involved, but only one principal designer.

Because of their important role in the planning stages of the project, the principal designer is one of the first appointments that should be made. The principal designer has a wide range of duties to discharge before any work begins on the site, and has overall responsibility for health and safety during the planning stages of the project.

5.-(2) The appointments must be made as soon as is practicable, and, in any event, before the construction phase begins.

What if you don't appoint a principal designer?

Under CDM it's the duty of the client to appoint a principal designer. So if you don't appoint a principal designer, there's a couple of different scenarios depending on if the client is domestic or commercial.

On domestic projects, if the client does not make the appointment in writing, the designer in control of the pre-construction phase of the project is the principal designer, and this appointment is automatic.

On commercial projects (construction projects in connection with any business), if the client does not make the appointment, they are automatically the principal designer, and responsible for the all the duties and requirements of that role.

(3) If the client fails to appoint a principal designer, the client must fulfil the duties of the principal designer in regulation 11 and 12.

cdm client
The principal designer is appointed by the client

When does a principal designer not need to be appointed?

Since the role needs to be appointed on all construction projects with more than one contractor, if you have only one contractor involved on your project for its duration (and they will not use any subcontractors), you don’t need to appoint a principal designer.

But you shouldn't wait until you have more than one contractor before appointing the principal designer. As discussed earlier, this should be one of the first appointments made. The regulations are quite clear that the appointment should be made "Where there is more than one contractor, or if it is reasonably foreseeable that more than one contractor will be working on a project at any time", so if it is likely you will need more than one contractor on the project, then get your principal designer in place.

It is worth noting that even if you have another contractor who is only doing a small amount of work, who is not on-site every day, that is still more than one contractor. If your contractor subcontracts part of his work, for example to a plumber or electrician, that is also more than one contractor.

As many projects require expertise from different trades, even small projects will usually need to appoint a principal designer.


Need to understand your CDM requirements? Read the free CDM duty holder guides, and use the free CDM compliance checklist to help you!

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This article was written by Emma at HASpod. Emma has over 10 years experience in health and safety and BSc (Hons) Construction Management. She is NEBOSH qualified and Tech IOSH.

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