Hiring a designer
CDM 2015 for domestic clients: what a homeowner owes when hiring an interior designer and a builder
The Construction (Design and Management) Regulations 2015 apply to a kitchen strip-out as much as to a tower block, but a homeowner who commissions the work is a domestic client whose legal duties pass automatically to the contractor or principal contractor. This article explains, from the Health and Safety Executive's own guidance, where those duties go, what the designer and builder must each do, and when a project must be notified on form F10.
Who is a domestic client under CDM 2015?
A domestic client under CDM 2015 is any individual who has construction work carried out on their own home, or the home of a family member, that is not done as part of any business, according to the HSE page on domestic clients, and CDM 2015 places the client duties on such a person only to pass them on to other dutyholders.
The HSE draws the line at business purpose. A client who has construction work carried out in connection with a business is a commercial client and carries the client duties in full. The HSE guidance does not name landlords, so an owner commissioning work on a let property should test the commercial client definition against the business purpose of the work rather than assume the domestic rules apply.
The HSE lists seven dutyholder categories in its CDM 2015 summary: commercial clients, domestic clients, designers, principal designers, principal contractors, contractors and workers. The regulations reach an interior designer through the designer category, which the HSE defines as organisations or individuals who, as part of a business, prepare or modify designs for a building, product or system relating to construction work.
Where do the domestic client's duties go?
The duties of a domestic client pass automatically to the contractor on a single-contractor project and to the principal contractor on a project involving more than one contractor, according to the HSE, and if the domestic client has not appointed a principal contractor the client duties must be carried out by the contractor in control of the construction work.
The one alternative route runs through the designer. Where a domestic client has appointed an architect or other designer on a project involving more than one contractor, the client can ask that designer to manage the project and take on the client duties instead of the principal contractor. The designer then takes on the responsibilities of principal designer and must have a written agreement with the domestic client confirming that arrangement. The HSE is specific about the consequence of an unwritten arrangement: any designer in charge of coordinating and managing a project is assumed to be the principal designer, but without a written agreement the client duties automatically pass to the principal contractor.
| Project shape | Who holds the client duties | Who is principal designer |
|---|---|---|
| One contractor, no designer | The contractor | No principal designer required |
| More than one contractor, no written agreement with a designer | The principal contractor, or the contractor in control if none is appointed | The designer in control of the pre-construction phase |
| More than one contractor, written agreement with the designer | The designer, as principal designer | The designer |
The HSE states that a domestic client does not need any skills, knowledge or experience of managing construction work. What the guidance asks of the homeowner is to make reasonable enquiries of the people brought in about their awareness of health and safety risks and their track record in managing them, and to allow sufficient time and money in the agreed contract for the work to be carried out safely.
What does a principal designer do on a domestic project?
A principal designer plans, manages, monitors and coordinates health and safety in the pre-construction phase of any project involving more than one contractor, according to the HSE page on principal designers, and on a domestic project where no principal designer is appointed that role must be carried out by the designer in control of the pre-construction phase.
The HSE lists the principal designer's duties as follows.
- Plan, manage, monitor and coordinate health and safety in the pre-construction phase, taking account of relevant information such as an existing health and safety file.
- Help and advise the client in bringing together pre-construction information, and provide the information designers and contractors need to carry out their duties.
- Work with any other designers on the project to eliminate foreseeable health and safety risks and, where that is not possible, to reduce or control them.
- Ensure that everyone involved in the pre-construction phase communicates and cooperates, coordinating their work wherever required.
- Liaise with the principal contractor, keeping them informed of any risks that need to be controlled during the construction phase.
For an interior designer, the practical consequence is that a project with a builder, an electrician and a joiner on site is a multi-contractor project, and the designer coordinating those trades is assumed to be principal designer whether or not the appointment letter says so. Only the written agreement decides whether the client duties travel with that role. BIID lists a free CDM helpline among the benefits of its Registered and Associate membership grades, and BIID members are required to hold professional indemnity insurance and to work under a written contract, as described in the article on what an interior designer costs in the UK.
What must the builder do under CDM 2015?
A contractor on any project must make sure the client is aware of the client duties before work starts, plan, manage and monitor the work, check that workers have the skills, knowledge, training and experience for it, provide site-specific inductions, supervision, information and instructions, prevent unauthorised access, and provide welfare facilities from the start, according to the HSE page on contractors.
The HSE adds duties for projects with more than one contractor: coordinating with the rest of the project team, complying with directions from the principal designer or principal contractor, and complying with the parts of the construction phase plan relevant to the contractor's own work. Where a contractor is the only contractor on a project, the HSE states that the contractor must ensure a construction phase plan is drawn up before setting up the site. When that sole contractor works for a domestic client, the contractor takes on the client duties as well, and the HSE states this should involve no more than the contractor normally does to comply with health and safety law.
| Duty (HSE, CDM 2015) | Single-contractor domestic project | Multi-contractor domestic project |
|---|---|---|
| Construction phase plan | Drawn up by the contractor before setting up site | Prepared by the principal contractor |
| Client duties | Taken on by the contractor | Taken on by the principal contractor, or by the designer under a written agreement |
| Coordination with other trades | Not applicable | Contractor complies with principal designer and principal contractor directions |
| Site induction and welfare | Contractor provides | Contractor provides unless the principal contractor already has |
| Making the client aware of client duties | Contractor | Each contractor |
When must a domestic project be notified to the HSE?
A construction project is notifiable to the HSE if the work is expected to last longer than 30 working days and have more than 20 workers working at the same time at any point, or to exceed 500 person days, according to the HSE CDM 2015 frequently asked questions, and the notification is made on form F10.
The two tests work independently. The first needs both conditions, duration over 30 working days and more than 20 workers at once, so a five-month house renovation with six trades on site never meets it. The second is a simple total: the HSE counts every day on which construction work is likely to be carried out, including holidays and weekends, so a 25-person crew for 21 days produces 525 person days and crosses the threshold in three weeks. The HSE states that the client has the duty to notify, and that in practice the client may ask someone else to notify on their behalf; on a domestic project that duty travels with the other client duties to the contractor, principal contractor or principal designer.
| Notification test (HSE FAQ) | Threshold | Example that crosses it (arithmetic) |
|---|---|---|
| Duration and peak workforce | More than 30 working days AND more than 20 workers at the same time | A 7-week fit-out with 22 people on site on the busiest day |
| Total labour | More than 500 person days | 25 workers for 21 days = 525 person days |
| Days counted | Every day work is likely, including weekends and holidays | A 6-day working week counts all 6 days |
Most single-house interior projects fall below both thresholds, but the plan, induction, welfare and coordination duties above apply regardless of notification.
What questions should a homeowner ask before appointing?
A homeowner meets the HSE's expectation of a domestic client by asking simple questions about each firm's track record in managing health and safety risks and by allowing sufficient time and money in the contract for safe working, according to the HSE guidance on domestic clients, which states that no construction knowledge is required of the client.
- Ask each contractor how it manages health and safety risks and for examples from similar domestic jobs, which is the reasonable enquiry the HSE describes.
- Ask who will be principal contractor if more than one firm will be on site, because the client duties default to that firm.
- Decide, in writing, whether the designer will act as principal designer and take on the client duties, since the HSE states that an unwritten arrangement sends those duties to the principal contractor.
- Ask the sole contractor on a small job to confirm that a construction phase plan will exist before the site is set up.
- Check the programme against the F10 thresholds if the project is large, using the 30-day, 20-worker and 500-person-day tests.
- Confirm that the designer holds professional indemnity insurance, which BIID requires of its members.
How does CDM 2015 interact with Building Regulations and the Party Wall Act?
CDM 2015 governs how construction work is planned and managed for health and safety, while Building Regulations approval, listed building consent and the Party Wall etc. Act 1996 are separate regimes that the same project may trigger, each with its own application and notice procedure.
The Building Regulations decide whether the work needs approval or a competent-person certificate and set the technical standards for electrics, energy, fire and access; the notice periods for work on a shared wall run under the Party Wall Act. The Building Regulations and the Party Wall Act are covered together in the article on Building Regulations for interior work in England. Consent for a listed house is covered in the article on listed building consent for interior alterations. A designer who takes on the principal designer role under CDM 2015 does not thereby take on responsibility for those applications unless the contract says so, which is one reason the BIID client guide asks for the scope of services to be written down before fees are agreed. The route to the qualifications that a principal designer is expected to bring to that role is described in the article on how to become an interior designer in the UK.
Questions readers ask about cdm 2015 for domestic clients
Does CDM 2015 apply to a home renovation?
Yes. The HSE defines 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 a business, and CDM 2015 applies to that work. The client duties pass to the contractor or principal contractor rather than resting on the homeowner.
Who takes the client duties on a domestic project?
On a single-contractor project the contractor takes on the client duties. On a project with more than one contractor the principal contractor takes them on, unless the domestic client has a written agreement with a designer to act as principal designer and carry out the client duties instead.
Can an interior designer be the principal designer?
Yes, on a project with more than one contractor, if the designer is in control of the pre-construction phase. The HSE states that a designer who coordinates and manages the project is assumed to be principal designer, but the client duties only transfer to that designer with a written agreement; without one they pass to the principal contractor.
When must a domestic project be notified to the HSE?
A project is notifiable if the construction work is expected to last longer than 30 working days and have more than 20 workers working at the same time at any point, or to exceed 500 person days. The HSE counts every day on which work is likely to be carried out, including weekends and holidays.
Does the builder need a construction phase plan for a small domestic job?
Yes. The HSE states that where a contractor is the only contractor on a project, the contractor must ensure a construction phase plan is drawn up before setting up the site. On multi-contractor projects the principal contractor prepares it.