Principal Designer in London

When you have to appoint one

The trigger is the number of contractors. In the words of the regulations: Where there is more than one contractor, or it is reasonably foreseeable that more than one will work on the project, the client must appoint in writing a principal designer and a principal contractor. The appointment must be made before the construction phase begins.

A kitchen extension with a builder, a separate electrician and a groundworker would meet that test. One firm doing everything under one contract follows a different route, covered below.

Skipping the appointment does not remove the duty. Where nobody has been appointed, the designer in control of the design phase is treated as the Principal Designer. That is how a homeowner can inherit an obligation by accident, and it is why we raise the appointment when we quote.

One contractor, a lead designer, and the shortcuts

The rule for a single contractor is this: A sole contractor is treated as principal contractor; a sole designer, or an agreed lead designer, fulfils the principal designer duties. The lead-designer agreement must be in writing, and you should hold a copy.

A second shortcut lets the client certify in writing that the person already appointed under the CDM rules is also treated as the Part 2A appointment. And some work is outside the system altogether: Part 2A does not apply where the building work or design work consists only of work described in Schedule 4. Before we quote the role, we check whether your project falls inside that list.

What the duties cover on a house

The duty is stated plainly: Plan, manage and monitor the design work and coordinate it so the building work, if built to the design, complies with all relevant requirements. On a house that means keeping the structural engineer's calculations, the drainage layout, the energy compliance and our own drawings consistent with one another, so an error found on site was not designed in.

When the appointment ends, the Principal Designer hands you a document describing the arrangements that were made, in the period the regulations set. Keep it with the house papers, because a future buyer's solicitor may ask for it.

We model each house once in 3D and issue every sheet from that model, so much of the coordination happens as the drawings are produced. Our building regulations drawings and the structural engineering input are checked against each other before issue.

Competence and changes of duty holder

Whoever you appoint needs the right capability. The regulations call for this: Skills, knowledge, experience and behaviours (individual) or organisational capability (organisation) to fulfil the principal designer duties; an organisation must designate an individual to manage the role. Someone still in training cannot be appointed, so ask any candidate how they meet the test.

If the Principal Designer or the principal contractor changes mid-project, the building control body must be told within 14 calendar days. We would raise the notice with you on the day a handover is agreed. Starting late is harder to put right than starting correctly, which is the practical reason to settle the appointment at the beginning.

The CDM side, briefly

Under the CDM Regulations a client appoints a Principal Designer and a principal contractor where more than one contractor is involved. For a householder the position is softer: Domestic client duties pass to the contractor (one contractor), the principal contractor (more than one), or the principal designer under a written agreement.

A project must also be notified to the Health and Safety Executive once it is big enough. The test is: Notifiable if construction work is scheduled to last longer than 30 working days with more than 20 workers simultaneously at any point, or to exceed 500 person days. We compare your programme and labour with those thresholds at quote stage, since most domestic jobs fall below them.

Price, process and who does the work

There is no published price, because the effort depends on the project's duration and the number of trades. You receive a fixed quote after a free constraints check, with no hourly surprises.

Most clients take the role together with the drawings, since the person holding the design is best placed to coordinate it. If another firm is drawing your project, we can quote for the role on its own.

If the scheme also needs a planning strategy, add a planning consultant. If you are at the very start, begin with planning drawings.