26th May, 2026
If you work in construction, you've probably heard about the CDM regulations. Maybe you are even familiar with the duties of clients, contractors, and designers. But do you know about part 4? It might not get much attention, but failing to comply is not an option. Find out how CDM Part 4 applies to your construction projects.
The Construction (Design & Management) Regulations (known as the CDM regulations) apply to all construction projects in Great Britain. This blog post is about part of the CDM regulations we don't often talk about - part 4.
Most people involved in construction projects have to comply with CDM:
They all have duties under CDM.
There are even two specific roles required under CDM. The principal designer and the principal contractor.
You might already know about the requirements placed on clients, principal designers, principal contractors, contractors and designers. These duties are placed on project team members by the CDM regulations and are what usually come to mind when you think of CDM.
In fact, the roles of the principal designer and principal contractor only exist because of CDM.
But this post is not about those duties, or CDM duty holders, because part 4 of the regulations is not about CDM duty holders.
If you are not fully up to speed on the duties you need to follow under CDM, you can check out our free CDM duty holder guides.
The CDM regulations are divided into five parts. The three main parts are Parts 2, 3 and 4. Part 1 is an introduction, and Part 5 is some general information on enforcement and review of the regulations.
Duty holder duties are covered under parts 2 and 3. Parts 2 and 3 of the CDM regulations tend to get a lot of attention. Part 2 details client duties, and Part 3 outlines health and safety duties for other roles. This includes details on the appointment of the principal designer and principal contractor, and what they must do.
It also covers duties applying to every designer and contractor on a construction project.
What about part 4 of the CDM regulations?
Part 4 of the CDM regulations contains general requirements for all construction sites. But it does not get much attention at all. If you look in the CDM approved code of practice, the section on part 4 simply includes the regulations.
The only additional guidance included for part 4 is...
Part 4 sets out a number of provisions that only relate to work carried out on the construction site. See HSE's construction web pages at www.hse.gov.uk/construction for guidance on these provisions.
So, if it's even glossed over in the guidance, is part 4 of CDM actually important?
Absolutely.
The CDM regulations are a set of 39 regulations. Part 4 contains regulations 16 to 35. That's nearly 50% of the regulations! For a section that doesn't get talked about much, that's a whole lot of regulations. You better believe it deserves some attention.
Part 4 of CDM is all about what happens on the site during the construction work. So the duties contained within part 4 are specific to contractors, and contractors must comply with these requirements on their construction sites.
- This Part applies only to a construction site.
- A contractor carrying out construction work must comply with the requirements of this Part so far as they affect the contractor or any worker under the control of the contractor or relate to matters within the contractor’s control.
- A domestic client who controls the way in which any construction work is carried out by a person at work must comply with the requirements of this Part so far as they relate to matters within the client’s control.
In addition, anyone who controls construction work must make sure that these requirements are complied with. Because if you control construction work, then you are a contractor under CDM.
“contractor” means any person (including a non-domestic client) who, in the course or furtherance of a business, carries out, manages or controls construction work;
Knowing part 4 of the regulations is essential for contractors and anyone controlling construction work. CDM prosecutions do happen, and the HSE will take enforcement action for breaches under part 4.
We only need to look at recent CDM prosecutions to find two significant prosecutions under CDM part 4.
A Manchester-based property developer was sent to prison for breaching Regulation 19 (stability of structures). In another prosecution, a breach of Regulation 27 (traffic routes) resulted in a £500,000 fine for a Birmingham-based contractor.
Find out more about CDM enforcement in 95 CDM Prosecutions (Breaches, Fines and Prison Time).
The requirements of Part 4 cover a wide variety of site issues, including:
For example, the regulations state that the colour of any artificial lighting must not affect or change the perception of any sign or signal provided for health and safety.
Many of the regulations in Part 4 will apply to every construction project you are working on. For example, good order, site security, weather protection, emergency routes and lighting. Others only on certain projects, like explosives, cofferdams and prevention of drowning.
Here's the full list of regulations included in CDM part 4:
Requires construction sites to be kept safe, including safe access to the construction site and every place construction work is carried out.
Construction sites must be kept in good order, including hoarding and signage. Requires a reasonable state of cleanliness and prohibits projecting nails and similar sharp objects.
18.—(1) Each part of a construction site must, so far as is reasonably practicable, be kept in good order and those parts in which construction work is being carried out must be kept in a reasonable state of cleanliness.
All new and existing structures must be protected from collapse and be able to withstand foreseeable loads.
Arrangements for demolition and dismantling must be recorded in writing and planned to prevent danger and reduce risk.
Explosives must be stored, transported and used safely and securely, with suitable steps in place to keep people safe when using explosives.
Steps must be taken to prevent excavations from collapsing and prevent people, equipment, or materials from falling into the excavation. Includes requirements for supports, inspections and preventing overloading.
Requirements for the design and construction of cofferdams and caissons, including inspection and maintenance.
Contains the requirements for inspection reports for inspections completed under regulations 23 and 24. Details the information to be included and storing copies.
The locating of energy distribution installations (including overhead and underground cables), and marking, checking, isolation and protection measures.
- Where there is a risk to construction work from overhead electric power cables—
- they must be directed away from the area of risk; or
- the power must be isolated and, where necessary, earthed.
Steps necessary to protect people from falling into water or other liquids- includes prevention and rescue requirements.
Producing a construction traffic management plan? The requirements for traffic route size and number, separation of vehicles and pedestrians and signage are found here.
Regulation 27 details the need to organise construction sites and provide adequate traffic routes to keep people safe. This regulation requires sufficient separation between vehicles and pedestrians.
Vehicles must be used and moved safely on construction sites. This regulation considers operator and vehicle safety.
Sufficient steps must be taken to prevent the risk of injury from fire, explosion, flooding or asphyxiation.
Requires arrangements for dealing with foreseeable emergencies, considering the site hazards and work carried out. These arrangements must be communicated and tested.
Emergency routes and exits must be provided on the site that lead to a place of safety. Just like any workplace, suitable signs and lighting, as necessary, are required.
Suitable fire detection and firefighting equipment are necessary on construction sites. These must be examined, tested, and properly maintained, with training provided.
32.—(1) Where necessary in the interests of the health or safety of a person on a construction site, suitable and sufficient fire-fighting equipment and fire detection and alarm systems must be provided and located in suitable places.
Construction sites must have sufficient fresh or purified air. Any plant required for this purpose must have visual or audible warning alarms in the event of failure.
The temperature of indoor areas must be reasonable. People working in outdoor areas must have protection from adverse weather.
Construction sites and their traffic routes must have suitable and sufficient lighting, which, as far as practical, should be natural light. This regulation includes the need for secondary lighting where artificial lighting may fail.
If you weren't aware of the CDM requirements above and beyond duty holders, and particularly if you carry out construction work, it may be worth having a recap of the CDM regulations and giving extra attention to Part 4. If you are a contractor, you certainly need to know about it.
Part 4 of the CDM regulations shouldn't be a secret. Hopefully, we have helped you uncover this sometimes forgotten section.
Unsure what you need to do to comply with CDM? Read our free CDM duty holder guides.
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.
Get CDM support on your construction projects with our free guides and support packs for all duty holders.
CDM Support
Painters and decorators are often familiar with CDM from working on larger construction projects, perhaps under a principal contractor. But what about smaller projects, like painting a hallway or a room in someone's house? How does CDM apply to painting and decorating work?
Read Post
If you work in construction, you've probably heard about the CDM regulations. Maybe you are even familiar with the duties of clients, contractors, and designers. But do you know about part 4? It might not get much attention, but failing to comply is not an option. Find out how CDM Part 4 applies to your construction projects.
Read Post
When, and how, does CDM 2015 apply to demolition work? As in, projects that don't involve any new construction. Demolition might involve breaking down walls, dismantling structures, removal, and site clearance. So if you're not building or constructing, but rather removing and dismantling, does CDM apply?
Read Post