CDM 2015 on a domestic job: the client duties that land on you

A homeowner asks you to build a rear extension. There is no client team, no safety adviser, no hoarding and no signing-in book, and the whole thing feels a long way from the sort of site the Construction (Design and Management) Regulations were written for. It is not. CDM 2015 applies to all construction work, and regulation 7 takes the duties the law puts on a client, looks at a homeowner, and hands them to the builder.

You are not appointed to it. Nothing gets signed. It happens by operation of law on the day the job starts, and it is the reason a two-person firm fitting a kitchen can be a statutory dutyholder without having read a word of the regulations.

The good news is that the paperwork it asks for is far smaller than the reputation of the regulations suggests. This page names the roles, tells you which one you are on a kitchen extension, and sets out the four things that follow: the construction phase plan, the risk assessment and method statement, the F10, and the RIDDOR report. Every rule below carries the regulation it comes from.

The sentence that does it

Regulation 7(1) of the Construction (Design and Management) Regulations 2015, SI 2015/51:

"Where the client is a domestic client the duties in regulations 4(1) to (7) and 6 must be carried out by ... (a) the contractor for a project where there is only one contractor; (b) the principal contractor for a project where there is more than one contractor; or (c) the principal designer where there is a written agreement that the principal designer will fulfil those duties."

The Construction (Design and Management) Regulations 2015, regulation 7

Then regulation 7(2) closes the other door. If a domestic client makes no appointments at all, which is the ordinary case, 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. There is no form for that and no moment at which anyone tells you it has happened.

Regulation 8(7) adds one more transfer that people miss. The duty to take reasonable steps to satisfy yourself that a designer or contractor has the skills, knowledge, experience and organisational capability for the role they are taking on is a client duty, and on a domestic job it is yours. When you put a groundworker on the job, checking they are up to it is now a statutory step rather than a commercial preference.

Someone on a self-build forum put the mechanism more plainly than most published guidance manages:

"If a domestic client does not appoint a principal contractor, the role of the principal contractor must be carried out by the contractor in control of the construction phase."

PeterW, on the BuildHub self-build forum

Who counts as a domestic client

Regulation 2 defines one: a client for whom a project is being carried out which is not in the course or furtherance of a business of that client. HSE puts the same test in the language of the job, describing a domestic client as any individual who has construction work carried out on their home, or the home of a family member, that is not done as part of any business.

The distinction decides who carries the duties, so it is worth being exact about it.

Where the client is commercial, regulation 5 requires them to appoint a principal designer and a principal contractor in writing whenever more than one contractor is involved, and regulations 5(3) and 5(4) leave the duties sitting on them if they do not. Where the client is domestic, regulation 7(3) switches that off and the transfer in regulation 7(1) does the work instead.

The six roles, and which one you are

CDM 2015 runs on dutyholder roles rather than job titles. The role attaches to what you are doing, not to what the contract calls you.

Now put a real job through it. A single storey rear extension at £41,800, nine weeks on site. You are a limited company with two employed labourers. You bring in a groundworks firm for the dig and the footings, a self-employed electrician, a plasterer and a scaffolder.

That is five contractors on one project, which means more than one, which means there has to be a principal contractor. The homeowner has made no appointments. Regulation 7(2)(b) makes it the contractor in control of the construction phase, and that is you. You did not accept the role, you occupied it.

The one arrangement that does not exist is the one where the homeowner keeps the duties because they hired the trades themselves. Regulation 7 does not offer that option.

What lands on you, item by item

Regulation 7(1) transfers regulations 4(1) to (7) and regulation 6. Stripped of the drafting, that is eight things.

Schedule 2 is where inspectors on small sites tend to start, because it is visible from the pavement. It requires suitable and sufficient sanitary conveniences, washing facilities with a supply of clean hot and cold or warm water, soap and a means of drying, an adequate supply of wholesome drinking water, changing and storage provision where the work requires special clothing, and rest facilities with tables, backed seating and a means of boiling water.

Builders on the same forum thread had already worked out the practical shape of it:

"Provide a loo and wash basin. Most will have a brew and a snack in there vans or in your house"

nod, on the BuildHub self-build forum

A hired welfare unit with a WC, a hot and cold basin, a kettle and four backed chairs runs at roughly £120 to £220 a week on a domestic drive, and it answers Schedule 2 paragraphs 1, 2, 3 and 5 in one delivery.

The construction phase plan, and what proportionate means

Regulation 12(1) puts the plan on the principal contractor, drawn up during the pre-construction phase and before setting up a construction site. Regulation 15(5) puts the same obligation on a sole contractor, as soon as is practicable prior to setting up a construction site. Between them, those two regulations mean a plan exists on every construction project in Great Britain, including a one-man bathroom rip-out.

Regulation 12(2) says what it has to do: set out the health and safety arrangements and site rules, take account of any industrial activity going on around the site, and include specific measures for work falling within Schedule 3. Schedule 3 is the high-risk list, and three of its ten categories turn up regularly on domestic work: work putting people at risk of burial under earthfalls or falling from height where the risk is particularly aggravated, work involving chemical or biological substances constituting a particular danger or requiring health monitoring, and work near high voltage power lines.

Nothing in regulation 12 says how long the plan should be, and HSE's own guidance for small builders is direct about it: a simple plan before the work starts is usually enough to show that you have thought about health and safety.

The plan is proportionate to the job. What it is not proportionate to is your firm's size, which is the reading that costs people money: the same two-page plan on the same extension is the right answer whether you turn over £90,000 or £9m.

A one-page construction phase plan you can actually use

HSE publishes a free template for exactly this, CIS80, "Construction Phase Plan (CDM 2015): What you need to know as a busy builder". CITB's free CDM Wizard app does the same job on a phone. The structure below is that shape, and it fits on one side.

CONSTRUCTION PHASE PLAN
Project:                              Plan version and date:

PLAN
  Your name / company and contact number
  Name and address of the client
  Contact details of the architect or principal designer
  What is the job? (scope, dimensions, structure, contract sum)
  Is there anything the client has made you aware of?
     services and isolation points / access restrictions / asbestos
  Key dates: start ......  finish ......  other ......
     services connected or disconnected
     build stages: groundwork, superstructure, roof, fit-out

ORGANISE
  Where are your toilet, washing and rest facilities?
  Who will be the principal contractor, and under which regulation?
  Who is supervising, and when are they on site?

WORKING TOGETHER
  Who else is on site, and their contact details
  How the site is kept updated during the job
     daily briefing / group message / who makes the key decisions
     what happens if the plan, the materials or the programme change

MAIN DANGERS AND THE CONTROLS
  Falls from height
  Collapse of excavations
  Collapse of structures
  Exposure to building dust
  Exposure to asbestos
  Electricity, buried and overhead services
  Risks to the public, the client and the household
  Activities or workers requiring supervision
  Other dangers on site

Signed .....................  Date .............
Reviewed on: ......  ......  ......

Filled in, on the extension at 14 Alder Road, it reads like this.

That is one side of A4, written in an evening, and it satisfies regulation 12(2) on that job. Regulation 12(4) then asks you to review, update and revise it as the job moves, which on a nine-week extension means dating the changes rather than rewriting the document.

RAMS: two documents doing two different jobs

RAMS is site shorthand for a pair of documents that get bound together and are often confused for one thing. They answer different questions and they come from different places in the law.

The risk assessment answers what could hurt someone and what you are doing about it. It comes from regulation 3 of the Management of Health and Safety at Work Regulations 1999, which requires a suitable and sufficient assessment of the risks to employees and to anyone else affected by the work. Regulation 3(6) requires the significant findings to be recorded where the employer has five or more employees. Below five, the assessment is still required, and writing it down is what lets you prove it existed.

Being self-employed does not take you outside this. The Health and Safety at Work etc. Act 1974 (General Duties of Self-Employed Persons) (Prescribed Undertakings) Regulations 2015 expressly list construction work and CDM dutyholder work as prescribed undertakings, so section 3(2) of the 1974 Act continues to apply to a sole trader on site.

The method statement answers in what order, with what, and by whom. No regulation names it. It exists because a control that is not tied to a sequence tends not to happen, and because a main contractor, a building control body or a homeowner's architect will ask for one.

Chimney breast removal shows the split cleanly.

Risk assessment:

Method statement, same job:

1. Survey result received and read. Confirm no asbestos in the flue seal or the Artex, or stop and instruct a licensed contractor.
2. Isolate and cap the gas run to the old fire. Isolate the socket circuit on the chimney wall and prove dead.
3. Sheet and board the room below. Lock it off. Set the barrow run and the skip position.
4. Prop the ceiling joists either side of the breast with Acrows and Strongboys to SK-02. Engineer to confirm before cutting.
5. Cut and remove the breast top down, working off a tower, with on-tool extraction running and FFP3 worn.
6. Install gallows brackets or the beam to the engineer's detail. Pin and pack.
7. Leave props in place for the period the engineer specifies. Record the date they came out.
8. Make good, remove the drop zone, clean down with an M class vacuum rather than sweeping.

The construction phase plan sits above both. The plan is the job. RAMS are the tasks inside it.

The F10: when a job is notifiable, and who sends it

Regulation 6(1) sets two limbs, and a project is notifiable if it meets either:

"last longer than 30 working days and have more than 20 workers working simultaneously at any point in the project; or exceed 500 person days."

The Construction (Design and Management) Regulations 2015, regulation 6

Two details decide most cases. First, HSE counts every day on which construction work is likely to be carried out, even if the work that day is short, and that includes weekends and bank holidays. Second, the first limb needs both halves, over 30 days and more than 20 people at once, while the second limb stands alone. That second limb is the one that catches long, thin jobs with a small gang.

On a commercial job the client notifies. On a domestic job, regulation 7(1) hands regulation 6 to you, so the notification is made by the contractor where there is one contractor, or by the principal contractor where there is more than one, or by the principal designer under a written agreement.

Regulation 6(2) requires the notice to go to HSE in writing as soon as is practicable before the construction phase begins. Schedule 1 lists the fifteen particulars it carries: the date of the notice, the site address, the local authority, a brief description of the project, contact details for the client, the principal designer and the principal contractor, the planned start date and duration, the time the client allocated under regulation 4(1), the estimated maximum number of people at work on site, the planned number of contractors, the names of any contractor and designer already appointed, and a declaration that the client is aware of the client duties.

The mechanics are narrow and worth knowing before the day you need them:

• The F10 is submitted through the online form at form.hse.gov.uk/f10. HSE no longer processes paper forms and does not accept notifications by email or post.
• Where there is only one contractor, HSE's own instruction is to enter the name of the sole contractor as both the principal designer and the principal contractor, and to use the free text box to explain that it is a single contractor project.
• Regulation 6(3) requires the notice to be displayed in the construction site office in a comprehensible form, and updated periodically as things change. On a domestic job the site office is usually the welfare unit, and a printed copy taped inside the door does the job.
• A notification already submitted can be edited later using the serial number and the email address on the form. Duration changes and role changes are the two that usually need it.
• HSE's customer services team takes questions on 0300 003 1747, Monday to Friday, 8:30am to 5pm.

Notifying is free, it takes about fifteen minutes, and where the person day count is anywhere near 500 it is far cheaper than the argument about whether it should have been sent.

RIDDOR: what gets reported, and by when

The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 sit alongside CDM rather than inside it, and they attach to the responsible person, which on your own site means you. The deadlines are short and they run from the day of the incident.

Three Schedule 2 dangerous occurrences come up on building work often enough to learn: the complete or partial collapse of a scaffold over 5m high, or of a slung or suspended scaffold platform; the unintentional collapse or partial collapse of a structure involving a fall of more than 5 tonnes of material, or of any floor or wall during construction work; and the collapse or partial collapse of falsework. Those are reportable whether or not anyone was hurt, which is the part people get wrong.

Reports go in through the online forms at notifications.hse.gov.uk. There is a separate form for injuries, for dangerous occurrences, for disease, and for gas incidents. Fatal accidents and specified injuries to workers can also be phoned in on 0345 300 9923.

Run one through. A labourer steps off a hop-up on Tuesday 8 September 2026 and fractures a wrist.

Had the same fall produced bruising rather than a fracture, and had he then been off routine work for nine days, the specified injury route would not apply and regulation 4(2) would give you until 23 September 2026 instead. Regulation 12 requires records to be kept at the place where the work is carried on or at your usual place of business, for at least three years, independently of whether a report was submitted.

Fee for Intervention, and the hour it charges

This is the regulation that turns a paperwork gap into an invoice.

Regulation 23 of the Health and Safety and Nuclear (Fees) Regulations 2022 (SI 2022/1378) makes a fee payable to HSE where an inspector finds a person contravening health and safety law and notifies them of it in writing. HSE calls that written notification a Notification of Contravention, and the trigger word is material breach: something the inspector considers serious enough that they need to formally write to the business requiring action. Verbal advice, or written advice without a Notification of Contravention, carries no charge.

Once the notification is issued, HSE recovers its time. The rate is £188 an hour, updated on 1 April 2026, and it covers the time taken to identify what is wrong and to help you put it right. That includes the visit, the writing, the review of anything you send in afterwards, and any revisit.

Invoices go out in January, March, May, July, September and November, within 30 working days of the end of each invoicing period, and payment is due within 30 days unless you are querying or disputing the invoice.

Here is what a single visit to a domestic extension with no plan and no edge protection costs.

That is roughly 3% of the contract sum on the extension above, for an afternoon. It also lands months later, in an invoicing window you have stopped thinking about, on a job that has been handed over and paid.

The document that keeps the visit advisory rather than chargeable is the one that already exists in your van: a dated construction phase plan naming the controls, the RAMS for whatever is happening that week, the scaffold inspection record, and a welfare unit on the drive. An inspector who sees those four things is looking at a site where health and safety has been thought about, and thinking about it is the statutory test.

The other principal contractor, since 1 October 2023

There is a second dutyholder regime running in parallel in England, and it uses the same two job titles.

The Building Regulations etc. (Amendment) (England) Regulations 2023, SI 2023/911, inserted Part 2A into the Building Regulations 2010 from 1 October 2023, creating a Building Regulations principal designer and a Building Regulations principal contractor. Those roles are about compliance with the Building Regulations, not about site safety, and they are separate appointments from the CDM ones. Regulation 11C transfers the domestic client duties in the same way regulation 7 does under CDM, and where there is only one contractor, that contractor is the Building Regulations principal contractor by default. At completion, the building control body wants compliance declarations signed by both Part 2A roles.

Self-builders have been running into it at the building regs submission:

"I've just encountered the same issue when our architects were preparing to submit to building regs, as apparently we need to appoint a Building Regulations Principal Designer and Building Regulations Principal Contractor under Part 2A of the Building Regulations."

WannabeBob, on the BuildHub self-build forum

In practice, on a domestic extension where you are already the CDM principal contractor by operation of regulation 7(2), you are usually the Part 2A principal contractor as well. Knowing which hat is being asked for makes the completion paperwork a five minute job rather than a fortnight of emails, and it is a good thing to raise with the homeowner's architect at drawing stage.

Where the rules change across the UK

CDM 2015 applies in England, Scotland and Wales. Northern Ireland runs its own set, the Construction (Design and Management) Regulations (Northern Ireland) 2016, SR 2016/146, enforced by HSENI, with the same dutyholder structure and the same domestic client transfer. RIDDOR reporting in Northern Ireland goes to HSENI rather than to HSE. Building Regulations Part 2A is England only, and Scotland runs a separate building warrant system under its own Building Standards regime.

What it costs

The plan costs nothing to produce. HSE's CIS80 template and CITB's CDM Wizard app are both free, the F10 notification is free, and RIDDOR reporting is free. The chargeable items are the welfare hire, roughly £120 to £220 a week on a domestic drive, and the inspector's time at £188 an hour if a material breach is found, which is the one line on the list you get to decide.

On AEC Stack there is no monthly subscription. The platform fee is 2.5% of each invoice processed through the platform, taken when the invoice is paid, so a quiet month costs nothing. Your construction phase plan, RAMS, survey results and scaffold inspection records sit against the job they belong to, so the version an inspector asks for is the version that is on the site rather than the one on a laptop at home.

Before your next domestic job starts, write the one page. Put the job, the survey result, the trades and the controls into your job record and print it for the welfare unit door.