CDM principal designer
CDM principal designer services
The statutory principal designer appointment under CDM 2015, taken as a standalone service on residential and smaller commercial projects. Fixed fees from £750 plus VAT, priced online in about two minutes.
In short
A CDM principal designer plans, manages and monitors health and safety through the design and pre-construction phase of a building project, and coordinates the designers so the risks their drawings create are dealt with before anyone is standing on site. Where a project will involve more than one contractor, CDM 2015 requires the client to appoint one in writing before construction begins. ClearCDM takes that appointment for house extensions, refurbishments, new houses and small commercial work, on a fixed fee, using structured online forms rather than a chain of emails.
What a CDM principal designer actually does
The role is defined by regulation 11 and regulation 12 of the Construction (Design and Management) Regulations 2015. Stripped of the legal phrasing, it is four jobs:
- Plan, manage and monitor the pre-construction phase
and coordinate health and safety matters through it, so that the work can be carried out without risks to health or safety so far as is reasonably practicable.
- Pull the project's information together
Help the client assemble the pre-construction information, work out what is missing, and get it to every designer and contractor who needs it, in a form they can use.
- Coordinate the design risks
Make sure each designer has dealt with the risks their own design creates: eliminated where that is possible, reduced or controlled where it is not, and clearly described where it is neither.
- Start the health and safety file
Prepare the file the building keeps, so whoever works on it in ten years is not starting blind.
When a principal designer must be appointed
Regulation 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 a designer with control over the pre-construction phase as principal designer, and a contractor as principal contractor. Regulation 5(2): the appointments must be made as soon as is practicable, and in any event before the construction phase begins.
Two things about that test are worth being precise about, because they are where most small projects get it wrong.
It is contractors, not designers. The trigger is the number of contractors, not the number of architects, engineers or designers. A single design practice on a job with a builder and an electrician still crosses the line.
Subcontractors count, and they do not have to overlap. A contractor under CDM 2015 is anyone who manages or carries out construction work in the course of a business. A builder who brings in a roofer for a fortnight and an electrician for a week has a project with three contractors on it, even though no two of them are ever on site together. That is why the honest answer for most extensions is that the appointment is required.
More on what more than one contractor means, and whether subcontractors count.
Does this apply to domestic projects?
Yes. CDM 2015 applies to work on your own home in the same way it applies to a commercial site. What is different for a domestic client is who carries the duties. Regulation 7(1) moves the client duties in regulations 4(1) to (7) and 6 onto the contractor, or on a multi-contractor project onto the principal contractor, unless the principal designer agrees in writing to carry them instead.
And regulation 7(2) deals with the case where the homeowner appoints nobody at all. The role does not lapse. The designer in control of the pre-construction phase is the principal designer, and the contractor in control of the construction phase is the principal contractor, whether or not either of them has been told, priced for it or knows the duty exists.
What happens if nobody is appointed, and how CDM applies to domestic projects.
What ClearCDM does
Five steps, short forms, one site visit. The whole sequence is set out on how it works, with a one page process map you can download and keep.
- Setup
The appointment in writing, and the project's basic information, through one short online form.
- Information
A different structured form for each party: the client, each designer, then the contractor. Nobody is asked for information somebody else already holds.
- Site visit
One visit to record the building as it actually is, rather than as the drawings assume it is.
- Coordination
Every designer deals with the risks their design creates, and the residual ones are written down rather than left in somebody's head.
- Issue
The pre-construction information pack and the information register, out to the project team before work starts.
Pre-construction information, built rather than templated
This is the part of the role most people never see, and the part that decides whether the document is any use. The difficulty on a small project is almost never that the information does not exist. It is that it is scattered: some with the client, some in the architect's drawings, some in a structural calculation, some in a survey nobody has opened since the purchase, and some only in the head of whoever last worked on the building.
ClearCDM collects it through structured forms aimed at the party who actually holds it, brings it into one project record, names what is missing and who can supply it, and then a person turns it into a document about that building. How we build the pre-construction information.
What the contractor receives
The pre-construction information pack goes to whoever is pricing and whoever is building. It sets out the site and its constraints, what is known about the existing building, the surveys and records that exist, the risks the design could not remove, and the arrangements for the health and safety file. It also carries the information register, which lists what is still awaited and who is providing it, so nothing is quietly assumed to be fine.
Under regulation 12(3) that information is what the principal contractor builds the construction phase plan on. More on construction phase plans.
The health and safety file
On projects with more than one contractor, regulation 12(5) requires the principal designer to prepare a health and safety file: the information about this project that is likely to be needed to keep people safe during any later work on the building. Where our appointment runs through to completion, the file is completed and handed to the client at practical completion as a single PDF. What goes in a health and safety file.
F10 notification, where the project reaches the threshold
A project is notifiable if the construction work is scheduled to last longer than 30 working days and have more than 20 workers working simultaneously at any point, or to exceed 500 person days. Most domestic extensions are nowhere near either figure. Where a project does reach the threshold, we can complete and submit the F10 to HSE on the client's behalf. Doing that does not move the duty: it stays where the regulations put it. More on F10 notification, or check your project against the threshold.
Two ways the appointment can run
| Route | Ends | Suits |
|---|---|---|
| Through to completion | At practical completion, with the health and safety file handed over | Most projects, because design carries on after work starts: structural details, contractor designed elements, substitutions |
| To start on site | At the start on site handover record | Projects with no ongoing design work during construction, or where the contractor or another principal designer picks the role up |
The quote offers both, with through to completion arriving pre-selected because it fits most projects.
This is the CDM role, not the Building Regulations one
Since October 2023 there has been a second, entirely separate principal designer role in England, created by Part 2A of the Building Regulations 2010. It is about designing to meet the Building Regulations, not about health and safety in construction, and it is appointed separately. ClearCDM provides the CDM 2015 role only, and says so on every quote.
The full comparison of the two principal designer roles.
Fees
Fixed, published, and quoted before you commit to anything. Fees start at £750 plus VAT for an extension, loft conversion or refurbishment of a single dwelling and are read off a published schedule rather than a percentage of your build cost. How the fees are built, or price your own project.
How the appointment happens
- Quote
Answer the questions in the instant quote tool and see the price. Nothing is contracted and no money is taken online.
- Review
We check every quote against the answers, normally within one working day, and confirm it or tell you what changes.
- Appointment
The appointment pack and the terms of appointment, accepted by a short signed online form. That signature is the written appointment regulation 5 asks for.
- Start
The forms go out to the project team and the site visit is booked.
Where we work
Bristol and Bath, across the South West, and in London and the South East. The fee is fixed wherever the project is, and the figure on your confirmed quote is the figure you are invoiced.
Common questions
Does a house extension need a CDM principal designer?
Usually yes. The test is not the size of the job, it is whether more than one contractor will work on it. A builder who brings in an electrician has made it a project with more than one contractor, so regulation 5 of CDM 2015 requires the client to appoint a principal designer in writing before the construction phase begins.
Is the CDM principal designer the same as the Building Regulations principal designer?
No. They are two separate roles under two separate sets of regulations, and a project in England can need both. ClearCDM provides the CDM 2015 role only.
Can my architect be the CDM principal designer?
Yes, if they are appointed in writing and are set up to do it. Many design practices exclude the role from their fee proposals, which is why the appointment is so often left unmade.
When does the appointment need to be made?
As soon as is practicable, and in any event before the construction phase begins. In practice that means while the design is still moving, because the role is about the pre-construction phase.
How much does a CDM principal designer cost?
ClearCDM fees start at 750 pounds plus VAT for an extension, loft conversion or refurbishment of a single dwelling, and the instant quote prices the whole job in about two minutes.
Sources
- CDM 2015, regulation 5: appointment of the principal designer and the principal contractor legislation.gov.uk
- CDM 2015, regulation 7: application to domestic clients legislation.gov.uk
- CDM 2015, regulation 11: duties of a principal designer legislation.gov.uk
- CDM 2015, regulation 12: construction phase plan and health and safety file legislation.gov.uk
- HSE: principal designers, roles and responsibilities hse.gov.uk
- Managing health and safety in construction, L153 HSE guidance on the Regulations
Price your project now
A few questions about the works and you have a fixed fee in about two minutes. Nothing is contracted and no money is taken online.
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