If you run a one-person construction business in the UK, you have probably heard of CDM 2015 and quietly hoped it does not apply to you. Most sole-trader builders assume the regulations are for larger firms working on big projects. They are wrong. The Construction (Design and Management) Regulations 2015 apply to every construction project in Great Britain, no matter how small, and they apply to sole traders.
The good news is that CDM 2015 for a sole trader is nowhere near as heavy as it is for a tier-one contractor on a multi-million-pound scheme. This guide walks through exactly what the regulations require of a one-person business, what paperwork you actually need, and what you can safely skip.
What CDM 2015 is, in one paragraph
CDM stands for Construction (Design and Management). CDM 2015 is the UK regulation that sets out who does what to keep construction projects safe. It gives specific duties to five groups: the client, the principal designer, the designers, the principal contractor and the contractors. For a sole trader doing work for a householder or a small firm, you will usually wear two hats at the same time: you will be the contractor, and sometimes also the principal contractor or even the designer.
Does CDM 2015 apply to a one-person builder?
Yes. CDM 2015 applies to every construction project in Great Britain. There is no exemption for small jobs, domestic clients or sole traders. What changes is the depth of what you have to do. A full rewiring job on a single cottage does not need a 40-page construction phase plan. It does, however, need proof that you have thought about safety before you start.
Who are you under CDM 2015?
As a sole trader you will most often be one or more of these roles:
- Contractor. Almost always. A contractor is anyone who actually carries out construction work. Every sole-trader builder is a contractor.
- Principal contractor. If you are the only contractor on site, you are not technically a principal contractor (that role only exists when there is more than one contractor). If you have hired any subcontractors, even a labourer for the day, you may become the principal contractor.
- Designer. If you are making decisions about how something is built (for example, specifying materials or detailing a structural solution), you are a designer under CDM.
- Principal designer. Only required on projects with more than one contractor. Most sole-trader jobs will not have one.
The two kinds of project: notifiable and non-notifiable
CDM 2015 divides projects into notifiable and non-notifiable. Notifiable projects are those which meet either of these thresholds:
- The construction phase is expected to last longer than 30 working days, with more than 20 workers working simultaneously at any point
- The total work involves more than 500 person days
If your project is notifiable, the client has to tell the HSE using an F10 form. If it is non-notifiable, no F10 is needed. Most sole-trader jobs, even decent-sized extensions, are non-notifiable.
Worth knowing: Notifiable or not, the rest of CDM 2015 still applies. Removing the F10 requirement does not remove the need to plan, manage and monitor the work.
Domestic clients: a special case
A domestic client is a homeowner having work done on their own home that has nothing to do with a business. Under CDM 2015, the client duties of a domestic client automatically transfer to the contractor. This matters because it means that as a sole-trader builder working for a homeowner, you take on the client duties yourself, on top of your contractor duties.
In practice that means:
- You make sure suitable arrangements for managing the project are in place
- You provide pre-construction information (even to yourself, in effect)
- On a project with more than one contractor, you make sure a principal contractor and a principal designer are appointed
If there is no written contract with the homeowner, CDM 2015 says the builder automatically becomes the client for the purposes of those duties.
Your duties as a contractor under CDM 2015
This is the bit that really matters for sole traders. As a contractor, you must:
- Plan the work. Think about hazards before you turn up. Decide on method, sequence, equipment and controls.
- Manage the work. Keep the plan alive on site. Adjust when things change. Record decisions.
- Monitor the work. Check what is actually happening matches what you planned. Stop when it does not.
- Provide information and instruction. Anyone working with or for you gets a briefing. That includes mates, labourers, apprentices and any subcontractors.
- Comply with directions from the principal designer or principal contractor. If you are working on someone else's site, follow their rules.
- Take account of the general principles of prevention. Essentially: eliminate risks where you can, reduce them where you cannot, and provide information and training to manage what is left.
The paperwork a sole trader actually needs
The following table shows the realistic paperwork for a sole-trader builder on a typical domestic project. Scale up or down based on the size and complexity of the job.
| Document | Needed? | Notes |
|---|---|---|
| Risk assessment | Always | Required by Management of Health and Safety at Work Regulations 1999. |
| Method statement | Usually | For significant tasks. See our how to write a method statement guide. |
| RAMS (combined) | Usually | Expected by most main contractors and many homeowners. |
| COSHH assessment | When using hazardous substances | Paints, cement, solvents, adhesives, fuels. |
| Construction phase plan | Always | Required on every project, however small. For small jobs it is a short document. |
| F10 notification | Only if notifiable | Projects over 30 working days with 20+ simultaneous workers, or 500+ person days. |
| Pre-construction information | For the work scope | Should cover existing drawings, asbestos surveys, known site hazards. |
| Health and safety file | Only with a principal designer | Usually not required on small sole-trader jobs. |
| Site induction record | If you have help | Even for a one-day labourer. |
| Toolbox talks | If you have help | Quick, documented safety briefings before risky tasks. |
| Public liability insurance certificate | Always | Not strictly CDM, but always requested. |
The construction phase plan for a sole trader
Every CDM project must have a construction phase plan, however small. For a sole trader on a one-week domestic job, a construction phase plan can reasonably be a two-page document covering:
- Project description and address
- Programme and working hours
- Key personnel (usually just you, plus any casual help)
- Welfare arrangements (even if that means using the householder's bathroom, by agreement)
- Key risks and how they are controlled
- Emergency arrangements, including nearest hospital and the householder's emergency contact
- Fire and first aid arrangements
It should be written before the first day on site and updated if the job changes. If an HSE inspector turns up, this is one of the first documents they will ask for.
When a sole trader takes on a subcontractor
The moment you bring in another contractor (even a mate who does a day's labouring and is paid for it), you become the principal contractor for that project. That triggers extra duties:
- Plan, manage and monitor the construction phase
- Prepare a construction phase plan (required anyway, but now with more detail)
- Make sure everyone is briefed on the plan
- Ensure welfare facilities are in place
- Coordinate the work of all contractors on site
Many sole traders prefer to stay genuinely solo for this reason. Others accept the extra duties and run their sites properly.
What the HSE actually looks for
When HSE inspectors visit small construction sites, they are not looking for perfect paperwork. They are looking for evidence of genuine planning and clear control on the day. The practical things that show up well in an inspection:
- A construction phase plan on site, even a short one
- A written risk assessment that reflects what is actually happening
- A toolbox talk or briefing record if there is more than one person working
- Working at height controls: scaffold tags in date, ladders tied, harnesses in good condition
- Respiratory protection in use where there is dust (especially silica)
- Segregated pedestrian and vehicle routes
- Welfare provision that is actually usable
- First aid kit and a named first aider if appropriate
A sole trader who can point to these is in a good position. A sole trader who cannot produce any written evidence that they have thought about safety is in trouble.
Common CDM 2015 mistakes sole traders make
- Believing CDM does not apply. It does. Every construction project, every size, every duration.
- No construction phase plan at all. This is the single most common failing on small sites.
- Generic risk assessments. Downloaded templates that do not reflect the actual job.
- Forgetting that domestic client duties transfer. Working for a homeowner means you pick up their client duties too.
- No record of briefings. Even a short note is better than nothing.
- Out-of-date documents. A risk assessment from two years ago that references a different site is not much use.
- No emergency arrangements. First aid kit missing, no idea of nearest A&E, no emergency number for the householder.
A practical weekly routine for sole-trader CDM compliance
If all of this feels like a paperwork mountain, break it into a simple weekly routine:
- Before the job: write a short construction phase plan, risk assessment and method statement. Check insurance. Check card dates.
- First day on site: walk the area, confirm the plan still fits, brief anyone helping, sign the briefing record.
- During the work: update the plan if anything changes. Keep a short site diary. Photograph unusual conditions.
- Weekly: review the plan, re-brief anyone helping, check equipment condition.
- After the job: file the documents with the project name and date. Keep them for at least three years.
How technology can help
Writing a fresh construction phase plan, risk assessment and method statement for every small job used to eat evenings. It is the main reason sole traders skip the paperwork. Site Manager AI is designed specifically for this: it produces UK-format CDM documents tailored to the job you describe, in minutes. You still sign, edit and take responsibility, but you start from a document that already reflects CDM 2015, COSHH and the Work at Height Regulations.
Worth knowing: Even a short, well-structured construction phase plan is a strong defence if something goes wrong. It shows you planned the work. Being unable to produce anything is the fastest way to turn a bad day on site into a formal HSE investigation.
FAQ: CDM 2015 for sole traders
Does CDM 2015 apply if I am the only person on site?
Yes. CDM 2015 applies to every construction project. The duties are lighter for a genuinely solo operation (no principal contractor role until you hire anyone), but the core duties as a contractor and the requirement for a construction phase plan still apply.
Do I need a construction phase plan for a two-day job?
Yes, one is still required. It can be short (one to two pages) and proportionate. Not having one at all is the problem.
If I work only for homeowners, do I need to do anything under CDM 2015?
Yes. When a homeowner has work done on their own house, CDM 2015 says the client duties transfer to the contractor. As a sole trader working for a homeowner you therefore pick up both the client and contractor duties.
What if I hire a labourer for one day?
You become the principal contractor for that project, because there is now more than one contractor. You must have a construction phase plan, brief your labourer, and manage and monitor the work accordingly.
Do I need to notify the HSE for my work?
Only if the project is notifiable: over 30 working days with more than 20 workers at any one time, or over 500 person days. Most sole-trader jobs are not notifiable.
What paperwork should I always have on a sole-trader job?
A construction phase plan, a written risk assessment, a method statement for significant tasks, a COSHH assessment if you use hazardous substances, and proof of public liability insurance. Our sample RAMS PDF is a useful starting point for the RAMS half.
Can Site Manager AI produce a CDM-compliant construction phase plan?
Yes. It generates short, CDM-aligned construction phase plans for small UK projects, along with matching RAMS and method statements. See the pricing page for current plans.
How long do I have to keep CDM records?
Keep them for at least three years after the end of the project. For projects with a health and safety file, the file should be kept for the life of the structure.
Will an HSE inspector really visit a small domestic job?
Unannounced visits to domestic projects are less common but they do happen, especially where there has been a complaint (for example from a neighbour) or a reportable incident. Having the paperwork in place is the simplest way to handle a visit without it turning into a formal investigation.