3rd May, 2022

Can The Principal Contractor Be The Principal Designer?

We often get asked if the principal contractor can be the principal designer under the CDM 2015 regulations. The principal designer should be the designer in overall control of the pre-construction phase. This is usually the architect, but in some situations, can be the principal contractor.

Can The Principal Contractor Be The Principal Designer? header image

A question we are often asked regarding the CDM regulations is, can the principal contractor be the principal designer?

The simple answer is yes, the principal contractor can be the principal designer, in some situations. But, this answer does come with some conditions.

It's not always the right decision for the principal contractor to be the principal designer, and in some cases, it could be a breach of the regulations.

Let's look at when and why it would, or wouldn't, be ok to be both the principal contractor and the principal designer under CDM.

The principal designer appointment

The title of the principal designer is more than just a name or a job title. It is a legal role under the Construction (Design and Management) Regulations 2015 (CDM). The principal designer has a variety of duties including to:

So if you're taking on the role, you need to be comfortable with those duties. And be in a position where you can fulfil those responsibilities.

It is important that whoever is appointed has the necessary skills, knowledge and experience, and the right involvement in the project, to carry out the role.

“principal designer” means the designer appointed under regulation 5(1)(a) to perform the specified duties in regulations 11 and 12;

The Construction (Design and Management) Regulations 2015 Interpretation

As you can see from the regulations, the principal designer is a designer who is appointed to carry out specific duties. It is important to note that there can only be one principal designer appointed on the project at any time, although there could be multiple designers.

The principal designer should be the designer in overall control of the pre-construction phase of the project. This is usually the lead architect, or sometimes the sole architect on the project.

Unsure what a principal designer does or how to comply? Get step-by-step help with the free principal designer CDM guide.

Since the principal designer needs to be appointed in writing, both the person making the appointment and the person being appointed need to be happy with the decision.

Both the appointee and the appointed have the legal duty to make sure the person being selected is competent to carry out the role.

cdm appointment by client

Appoint a principal designer on your project with the Principal Designer Appointment CDM Template.

When the principal contractor can be the principal designer

Now we know who the principal designer is, how can the principal contractor be the principal designer? Shouldn't the principal designer be a designer?

Yes, they should, but of course, some projects, especially smaller projects, might not have an architect involved.

Not all construction project teams are the same, and with CDM 2015 applying to a wide range of projects including maintenance, demolition, earthworks, and refurbishment, there are often cases where it is not clear who the principal designer should be.

What about design and build contracts, where the design and the construction work is handed over to one company? The design and build company in these circumstances could have both contractor and designer duties under CDM.

This is a classic example of where it would be acceptable to appoint the principal contractor also as the principal designer.

Organisations or individuals can carry out the role of more than one dutyholder, provided they have the skills, knowledge, experience and (if an organisation) the organisational capability to carry out those roles in a way that secures health and safety.

As long as the principal contractor has the skills, knowledge, experience and capability to carry out the role of the principal designer, and is acting as a designer in some capacity, they could be your best choice. Especially if they are the designer in overall control of the pre-construction phase of the project.

What about a kitchen installation company that is carrying out the design and installation of a new kitchen, with subcontractors for the electrical and mechanical services?

cdm contractor residential

The project will need both a principal contractor and a principal designer. It would make sense that the kitchen installation company fulfils both roles since it is in overall control of both the design and managing the work on site.

When the principal contractor can't be the principal designer

So the principal contractor can be the principal designer. Whether or not they should be will depend on the particular project.

In a design and build project, or maintenance work where the contractor is responsible for the design of the system or project, this can be a suitable choice.

Like the examples we looked at in the previous section, there are times when the contractor also handles the design work.

However, there are also times when a principal contractor can't be the principal designer. And this is probably the more common situation.

In the traditional construction tendering process, much of the design work for the project is done before contractors are selected. An architect and the rest of the design team put together the project design and specification, and send it to contractors who bid for the work.

The principal designer is one of the first appointments needed under CDM. It wouldn't be practical for the principal contractor to be the principal designer in this case. Because they haven't been selected yet!

Many of the principal designer duties need to get discharged before the construction work begins on the site. If the contractor hasn't even been appointed at that stage, they can't possibly discharge the duties at the right time.

cdm principal designer

Remember, the principal designer is the designer in overall control of the pre-construction phase.

When the design work is being carried out, the principal designer needs to be in charge of health and safety and ensure CDM is complied with at this stage.

The principal designer has a wide range of duties to carry out at the pre-construction phase. If a principal contractor has not yet been appointed, and are not involved in the design, it would not be possible for them to be the principal designer.

One of the designers will need to be appointed as the principal designer.


It is important to remember that CDM applies during all stages of the project, and if the client does not appoint a principal designer, they are automatically responsible for the principal designer's duties.

You can find out more about CDM and get step-by-step guides on complying with your duties, in our free CDM duty holder guides.

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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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