Construction compliance guide
CDM Domestic Client Duties: What Transfers to the Builder
On domestic work with only one contractor, CDM client duties transfer automatically to that contractor. Where there is more than one contractor they pass to the principal contractor by default — or, where there is more than one contractor, to a principal designer under a written agreement. Here’s what that means, why it matters, and how to stay compliant without drowning in paperwork.
TL;DR
On domestic work with only one contractor, CDM client duties transfer automatically to that contractor under regulation 7(1)(a). Where there is more than one contractor they pass to the principal contractor, or, where there is more than one contractor, to the principal designer under a written agreement. Here’s what that means and how to stay compliant without drowning in paperwork.
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What is a domestic client?
Under CDM 2015, a domestic client is someone who has construction work done on their own home, or the home of a family member, and the work is not connected to a business. This covers the vast majority of residential construction: extensions, loft conversions, kitchen refits, new bathrooms, rewiring, roofing work.
The distinction matters because domestic clients are treated differently under the regulations. They are not expected to understand CDM or manage health and safety on a construction project — so the law shifts those responsibilities to the people who do understand it: the contractors.
One common trap: if a landlord is having work done on a buy-to-let property, they are not a domestic client. That is a commercial client because the property is part of a business. The same applies to anyone having construction work done in connection with a trade, profession, or business activity. If in doubt, ask whether the property is the client’s own home and whether the work is entirely personal — if the answer to both is yes, they are a domestic client.
The automatic transfer of duties
This is the key point that is easiest to miss. Under CDM 2015 Regulation 7, domestic clients are not required to carry out client duties themselves. Instead, those duties transfer automatically:
One contractor on the job
On a domestic project with only one contractor, the regulation 4 and 6 client duties pass to that contractor. If you are the only builder on a domestic project, those duties are yours by default.
Multiple contractors
If there is a principal contractor, the duties pass to them. If no principal contractor has been appointed on a job with more than one contractor, regulation 7(2) deems the contractor in charge of the construction phase to be the principal contractor. The client’s duties then pass to that deemed principal contractor by default under regulation 7(1)(b), exactly as they would to an appointed one.
Where there is more than one contractor, the domestic client can make a written agreement with a principal designer to transfer those duties instead — including the duty to notify the HSE. On a job with only one contractor there is no principal designer to make that agreement with, so the duties stay with that contractor. There is no equivalent duty-transfer agreement for a principal contractor: a principal contractor already gets the duties by default whenever there is more than one contractor on the job. That’s a separate question from the principal contractor’s own appointment, though — on a project with more than one contractor, a principal contractor must still be appointed in writing under regulation 5. If the client never makes that appointment on a job with more than one contractor, regulation 7(2) deems whichever contractor is in charge of the construction phase to be the principal contractor instead — the same fallback described above; a sole contractor instead holds the duties directly, with no principal contractor role to deem. In practice, on the vast majority of domestic jobs, the builder ends up with client duties by default — because few homeowners know enough about CDM to make a formal written agreement with a principal designer where more than one contractor is involved.
What this means for you as the builder
If client duties transfer to you, your separate contractor or principal-contractor duties still apply. In practice, you must:
- Ensure the project is properly planned and managed from start to finish
- Produce a Construction Phase Plan before work begins on site
- Ensure adequate welfare facilities are available for all workers
- Ensure all workers on the project are competent and have the right training
- As contractor, ensure workers under your control receive a suitable induction unless the PC already provided it; as PC, ensure a suitable induction is provided
You cannot blame the homeowner for not doing these things — the law says those duties are yours. This catches a lot of builders out. They assume CDM is something the client sorts out, or that domestic work is somehow exempt. On domestic work, it is not exempt — and the responsibility sits squarely with the contractor.
The good news is that the scale of what you need to do is proportionate. A small domestic job does not require the same level of documentation as a multi-million-pound commercial project. But you do need to have the basics in place.
The lightweight CPP for domestic work
A Construction Phase Plan for domestic work does not need to be a 20-page document. The HSE has said repeatedly that the plan should be proportionate to the project. For a kitchen extension or bathroom refit, a well-written 1–2 page plan covering the key risks, management arrangements, and welfare provisions is perfectly adequate.
What matters is that the plan is site-specific. A generic template that you use on every job without changing anything will not cut it if the HSE comes calling. The plan needs to reflect the actual risks of the actual project — the site, the work, the people involved.
The Site Book’s Lightweight CPP wizard is designed exactly for this. Answer four questions about your job — what the work is, where it is, who is doing it, and what the main hazards are — and it creates a proportionate, site-specific plan. No jargon, no 50-page templates, just a clear plan that does the job.
When domestic work becomes notifiable
Even domestic projects can be notifiable if they meet the CDM thresholds:
Threshold 1
The construction phase will last longer than 30 working days and have more than 20 workers on site at any one time.
Threshold 2
The project will exceed 500 person-days in total.
In practice, most domestic jobs will not hit these thresholds. But larger projects — whole-house renovations, major extensions with multiple trades working over several months — sometimes do. If a domestic project is notifiable, the regulation 6 duty passes to the contractor where there is only one contractor, or — where there is more than one contractor — to the principal contractor, unless a principal designer agrees in writing to fulfil it. The duty holder must ensure an F10 is submitted to HSE at the time regulation 6 requires.
How The Site Book handles domestic projects
When you select “domestic” as your project type in The Site Book, the system automatically adjusts to match your situation:
Lightweight CPP wizard
Instead of the full commercial CPP template, you get the streamlined domestic version. Answer four questions to draft a plan proportionate to the work.
Domestic welfare arrangements
The plan includes domestic-specific welfare provisions — such as using the homeowner’s toilet and washing facilities by agreement — rather than assuming you will have portable cabins on site.
Transfer of duties noted
Your documentation clearly records that client duties have transferred to you under Regulation 7. This is important if you ever need to demonstrate compliance to the HSE or an inspector.
Notifiability check
The Site Book checks your project details and tells you whether the job is notifiable. If it is, the F10 is pre-filled from your project data.
Frequently asked questions
Does the homeowner have any responsibilities under CDM?
A domestic client keeps the regulation 5 duty to appoint a principal designer and principal contractor in writing where more than one contractor is, or is reasonably foreseeable to be, involved. On a domestic project with only one contractor, the regulation 4 and 6 client duties pass to that contractor by default; where there is more than one contractor, they pass to the principal contractor by default, or, where there is more than one contractor, instead to a principal designer who agrees in writing to fulfil them. If the required appointments are not made on a domestic project with more than one contractor, regulation 7(2) treats the designer in control of pre-construction as principal designer and the contractor in control of construction as principal contractor.
What if the homeowner wants to appoint their own principal designer?
Where there is more than one contractor, a domestic client can make a written agreement with the principal designer to transfer the client's CDM duties instead of using the default arrangement — including the duty to notify the HSE. With only one contractor there is no principal designer, so no such agreement is possible and the duties sit with that contractor. This is more common on larger domestic projects where an architect is already involved. The agreement must be in writing, and the principal designer must be competent and willing to take on the duties. There is no equivalent duty-transfer agreement for a principal contractor — a principal contractor already receives these duties by default whenever there's more than one contractor. That's a different question from the principal contractor's own appointment, though: on a project with more than one contractor, a principal contractor must still be appointed in writing under regulation 5. If the client never makes that appointment on a job with more than one contractor, regulation 7(2) deems whichever contractor is in control of the construction phase to be the principal contractor instead — a sole contractor holds the duties directly under regulation 7(1)(a) instead, with no principal contractor role to deem. If there is no written agreement with a principal designer, the duties remain with the principal contractor (if there's more than one contractor) or the contractor (if there's only one contractor).
Do I need a written contract with the domestic client for CDM purposes?
CDM 2015 does not specifically require a written contract between you and the domestic client. However, having a written agreement is strongly recommended for practical and legal reasons. It clarifies the scope of work, confirms who is responsible for what, and provides evidence of your arrangements if anything goes wrong. A written agreement also helps demonstrate that you have planned the work properly, which is one of your core duties under CDM.
What welfare facilities do I need on a domestic job?
You must ensure adequate welfare facilities are available for everyone working on the project. On domestic jobs, this often means agreeing with the homeowner to use their toilet, washing facilities, and somewhere to take breaks. This arrangement should be confirmed before work starts and recorded in your Construction Phase Plan. If the homeowner’s facilities are not available or not suitable, you must make alternative arrangements — for example, a portable toilet and hand-washing station.
Can a domestic client be prosecuted under CDM?
Regulation 7 does not make a domestic client exempt from CDM 2015 or decide enforcement in a particular case. On a domestic project with only one contractor, the regulation 4 and 6 client duties pass to that contractor by default; where there is more than one contractor, they pass to the principal contractor by default, or, where there is more than one contractor, instead to a principal designer who agrees in writing to fulfil them. The domestic client keeps the regulation 5 appointment duty where more than one contractor is, or is reasonably foreseeable to be, involved. If the required appointments are not made on a domestic project with more than one contractor, regulation 7(2) treats the designer in control of pre-construction as principal designer and the contractor in control of construction as principal contractor.
Domestic-client CDM — what transfer means in practice
Pros
- On domestic work with one contractor, client duties pass to that contractor by default; with more than one contractor, they pass to the PC unless a PD agrees in writing.
- On single-contractor domestic jobs the default duty transfer is automatic: no written agreement needed for it to apply.
- You can document the transfer in a short scope letter, which protects both sides if the job runs into trouble.
- The builder is the one person on site who actually understands construction risk — so putting duties with them, by default, is proportionate.
Cons
- Most sole traders do not realise the duties transfer, and price jobs without accounting for CDM overhead.
- On a multi-contractor domestic job with no PC appointment, regulation 7(2) deems the contractor controlling the construction phase to be PC.
- On a domestic job with one contractor, duties pass to that contractor under reg 7(1)(a); the written-agreement route to a PD (reg 7(1)(c)) exists only where there is more than one contractor.
- If no PC is formally appointed on a multi-contractor job, CDM assigns the role by default to whichever contractor is in control (reg 7(2)) — not a real gap, but who that is can be unclear in practice.
| Duty | Who holds it on commercial jobs | Who holds it on domestic jobs |
|---|---|---|
| Provide pre-construction information | Client | Only contractor (one contractor) or principal contractor (more than one) by default; written-agreement principal designer instead where there is more than one contractor |
| Appoint Principal Designer (>1 contractor) | Client | Client keeps the duty; on a multi-contractor job with no appointment, reg 7(2) deems the designer in control of pre-construction the PD |
| Appoint Principal Contractor (>1 contractor) | Client | Client keeps the duty; on a multi-contractor job with no appointment, reg 7(2) deems the contractor in control the PC |
| Ensure CPP is produced | Client verifies | Client duty: only contractor (one contractor) or principal contractor (more than one contractor) by default; plan authorship stays with the only contractor or PC |
| Ensure welfare facilities | Client arranges access | Only contractor (one contractor) or principal contractor (more than one) by default; written-agreement principal designer instead where there is more than one contractor |
| H&S file kept until handed to client | The PD prepares and keeps it; the client receives it at the end (regs 12(5)–(6), 12(10)) | With one contractor there is no principal designer and no reg 12 file duty. Where there is more than one contractor, the PD keeps the file, never the contractor — the PC takes over only if the PD's appointment ends early (regs 12(8)–(10)) |
“Although CDM 2015 still places duties on domestic clients, in almost all cases these duties automatically pass to other duty holders.”
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Sources
- CDM 2015 — Domestic clients — HSE · Accessed 17 April 2026