A CDM consultant helps clients and project teams meet the Construction (Design and Management) Regulations 2015 (CDM 2015). The most common appointment is the principal designer, which the law requires whenever more than one contractor will work on a project. Published fee guides say principal designer services for a small project usually start at about £1,000–£2,000, and on projects worth £5 million or more one published fee schedule estimates about 0.16%–0.22% of the build cost.
Principal designer, CDM adviser or CDM coordinator?
Principal designer
Appointed in writing by the client to plan, manage, monitor and co-ordinate health and safety in the pre-construction phase, and to prepare the health and safety file.
Must be a designer with control over the pre-construction phase.
CDM adviser (CDM advisor)
Advises the client on its duties, appointments, pre-construction information and HSE notification, without taking on a legal role itself.
The scope is agreed with the client, not set by the regulations.
CDM coordinator
The role under the old CDM 2007 regulations. CDM 2015 came into force on 6 April 2015 and replaced it with the principal designer, after a transition that ended on 6 October 2015.
HSE says the principal designer is not a direct replacement: the duties are different.
Who needs a principal designer?
CDM 2015 applies to construction work in Great Britain, whatever its size. Where there is more than one contractor, or it is reasonably foreseeable there will be, the client must appoint in writing:
A principal designer Legal
A designer with control over the pre-construction phase. On smaller projects it can be an individual.
A principal contractor Legal
A contractor who plans, manages and co-ordinates the construction phase and draws up the construction phase plan.
When to appoint Timing
As soon as is practicable, and in any event before the construction phase begins. If the client doesn't appoint them, the client must carry out the principal designer's and principal contractor's duties itself.
Competence
Anyone appointed must have the skills, knowledge and experience, and, if an organisation, the organisational capability, to do the role. The person appointing them must take reasonable steps to check.
Client duties under CDM 2015
A commercial client is anyone having construction work done as part of a business. These duties apply on every project, including single-contractor jobs.
- Make suitable arrangements. Allow enough time and resources for the work to be done safely, including welfare facilities.
- Provide pre-construction information. As soon as practicable, to every designer and contractor being considered or appointed.
- Make sure there is a construction phase plan before the construction phase begins.
- Make sure a health and safety file is prepared by the principal designer where there is one, and keep it available.
- Check the principal designer and principal contractor are doing their jobs, taking reasonable steps.
- Pass the file on to the new owner if you sell the building.
Householders (domestic clients)
A householder having work done on their own home, or the home of a family member, not as part of a business, is a domestic client. Their client duties pass automatically: to the contractor on a single-contractor job, or to the principal contractor where there is more than one. A principal designer can take them on instead, but only with a written agreement.
If a householder doesn't appoint a principal designer and principal contractor where they are needed, the designer in control of the pre-construction phase becomes the principal designer and the contractor in control of the construction phase becomes the principal contractor. So most householders don't need to hire a CDM consultant, but on an extension with separate trades, it is worth agreeing in writing who holds each role.
F10 notification: when to tell HSE
A project is notifiable if it meets either test. HSE's guidance says every day construction work is likely to take place counts, including weekends and bank holidays.
- Who notifiesThe client. On domestic projects, the contractor or principal contractor notifies, or the principal designer if there is a written agreement.
- WhenAs soon as is practicable before the construction phase begins.
- HowOnline, using HSE's F10 form. HSE no longer accepts paper forms, email or post. You get a serial number to update the notification later.
- Display itA copy must be clearly displayed in the site office where workers can read it, and kept up to date.
The three CDM documents
| Document | Who prepares it | When it is needed |
|---|---|---|
| Pre-construction information | The client, helped by the principal designer | Every project. Given to designers and contractors bidding for or appointed to the work. |
| Construction phase plan | The principal contractor, or the contractor on a single-contractor job | Every project. Drawn up before the site is set up, setting out health and safety arrangements and site rules, and reviewed as work goes on. |
| Health and safety file | The principal designer, or the principal contractor if the designer's appointment ends first | Projects with more than one contractor. Information for future work on the building, handed to the client at the end. |
CDM principal designer or Building Regulations principal designer?
| CDM principal designer | Building Regulations principal designer | |
|---|---|---|
| Law | CDM 2015 | Building Regulations, as amended in 2023 |
| Where | Great Britain | England |
| Purpose | Health and safety of workers and others affected | Design work complies with building regulations |
| When needed | More than one contractor | More than one contractor |
Each role has its own competence requirements. The same person or firm can hold both: instead of making a separate appointment, the client can certify in writing that the CDM principal designer is also the Building Regulations principal designer. On domestic projects, if the householder doesn't appoint one, the designer in control of the design phase becomes the Building Regulations principal designer by default.
What principal designer services cost
Most CDM consultants charge a fixed fee on small projects and a percentage of the build cost on larger ones. These ranges come from consultants' published fee guides, usually excluding VAT.
- Appointment or adviceTaking on the principal designer role carries legal duties and usually costs more than advising the client.
- Project value and complexityBigger, notifiable projects mean more design reviews, meetings and paperwork.
- Site visits and meetingsAgree how many are included and what extras cost.
- One role or twoTaking on the Building Regulations principal designer role as well adds work.
Check whether each quote is for the principal designer appointment or only advice, whether it covers the pre-construction information, the health and safety file and F10 notification, how many meetings and visits are included, and whether VAT and travel are extra.
What to check before you hire
Ask to see membership certificates and insurance, and check them on the body's own register.
APS (Association for Project Safety)
A professional institution for construction health and safety risk management, focused on CDM. Its website has a find-a-member search.
IOSH chartered membership (CMIOSH)
Chartered Member of IOSH, which requires senior experience, an assessment and ongoing CPD.
OSHCR
The Occupational Safety and Health Consultants Register lists consultants with chartered-level membership of a participating body, professional indemnity insurance and up-to-date CPD. HSE points people to it.
RIBA Principal Designer Register
For RIBA chartered architects who show they meet the competence criteria for the CDM and Building Regulations principal designer roles.
Professional indemnity insurance
Covers claims arising from poor advice or design co-ordination. OSHCR requires it of registered consultants.
Wider health and safety support
Many CDM consultants also offer site audits, RAMS and a retained competent person service. Our separate guide to health and safety consultants covers these services and their costs. Before refurbishment or demolition, you may also need an asbestos survey.
Questions to ask a CDM consultant
- Are you quoting to be principal designer, or to advise?
- Is that the CDM principal designer, the Building Regulations principal designer, or both?
- Are you an APS member, CMIOSH or on OSHCR? Can I see your certificates?
- What professional indemnity insurance do you carry?
- Will you handle the F10 notification if the project is notifiable?
- How many meetings and site visits are included, and does the price include VAT?
Prices in this guide are typical ranges from suppliers' published price lists and cost guides. They change and vary by area, so always confirm the price with the supplier before you book. Rules, fees and tax rates are checked against official sources.