Which role is which
Can the same person be both principal designers?
Short answer
Yes. Nothing stops one organisation holding both the CDM principal designer appointment and the Building Regulations principal designer appointment, provided it is competent for both and is a designer with the relevant control. Regulation 11D(2) of the Building Regulations 2010 goes further and lets the client certify in writing that the CDM principal designer is treated as appointed to the Building Regulations role. The risk is using that shortcut where the firm does not actually provide both.
Where it works well
A design practice leading the whole project is often the natural holder of both. It controls the design work, which is what regulation 11D asks for, and it controls the pre-construction phase, which is what regulation 5 of CDM 2015 asks for. Holding both keeps the coordination in one place.
The same question from the Building Regulations side, including what regulation 11D(2) does there, is answered by Parallel Architecture, which shares an owner with ClearCDM: can one person hold both principal designer roles?
Where it goes wrong
Two situations recur.
A specialist CDM consultant certified into the Building Regulations role. The client signs the 11D(2) certificate because it is offered as a tidy administrative step. The consultant provides the CDM role only. On paper the Building Regulations appointment exists; in practice nobody is coordinating design for Building Regulations compliance.
Assuming one appointment covers both. A written CDM appointment says CDM. It does not create a Building Regulations appointment, and Part 2A does not treat it as one unless the client certifies under 11D(2).
ClearCDM's position. We provide the CDM 2015 role only. Do not use the regulation 11D(2) certification route to name us as the Building Regulations principal designer, because we do not provide it. That appointment should be made separately.
The competence question
Part 2A carries its own competence requirements. Regulation 11F requires anyone carrying out building work or design work to have the skills, knowledge, experience and behaviours necessary to do it in accordance with all relevant requirements, and regulations 11G and 11H add requirements specific to the principal designer and principal contractor roles. Competence for one role is not competence for the other, because the subject matter is different.
Sources
Find out where your project stands
The free checker asks six questions and tells you whether the appointment is required, and why.
Open the checker →Not sure yet? go straight to a fixed fee.