The Construction (Design and Management) Regulations 2007 places specific duties on the approach to health and safety. However, on 6 April 2015, CDM 2007 was revoked and replaced by the Construction (Design and Management) Regulations 2015 (CDM 2015).


This means that the provision of health and safety legislation now applies to domestic building projects. So, self and custom builders now become responsible for their own safety when working on their own projects.

Although, depending on how much of the project work you take on yourself, you could fall into one, or more, of the following categories, listed here under the term ‘dutyholders’:

CLIENTS – organisations or individuals for whom a construction project is carried out.

What do I need to know?

DOMESTIC CLIENTS – people who have construction work carried out on their own home, or the home of a family member that is not done as part of a business, whether for profit or not.

What do I need to know?

DESIGNERS – those, who as part of a business, prepare or modify designs for a building, product or
system relating to construction work.

What do I need to know?

PRINCIPAL DESIGNERS – designers appointed by the client in projects involving more than one contractor. They can be an organisation or an individual with sufficient knowledge, experience and ability to carry out the role.

What do I need to know?

PRINCIPAL CONTRACTORS – contractors appointed by the client to coordinate the construction phase of a project where it involves more than one contractor.

What do I need to know?

CONTRACTORS – those who do the actual construction work and can be either an individual or a company.

What do I need to know?

WORKERS – people who work for or under the control of contractors on a construction site.

What do I need to know?


There are a number of potential scenarios. In all these scenarios the self builder is a ‘domestic client’: if the structure they are building will be a residential home they will live in, and is not constructed as part of a business.

If the self builder is carrying out the work for a business purpose, or to sell the property directly, then the self builder is not a domestic client and the whole of CDM 2015 applies.

Let’s explore these self build scenarios a little further:

  1. The self builder does it all himself, employs no contractors, and uses the structure constructed as a home to live in afterwards. This will be a DIY project because no-one involved is ‘at work’ in the meaning of the Health and Safety at Work etc Act 1974.
  2. The self builder appoints an architect or designer as Designer or Principal Designer (Principal Designer where there is likely to be more than one contractor engaged on the project) and appoints that person or business to take on the client duties on behalf of the self builder. In this instance the Principal Designer may also be appointed as Principal Contractor, for the purpose of co-ordinating the construction phase, if that person or business has the skills, experience and knowledge to do the job. It is likely that many traditional architects will have the necessary project management skills and experience to carry out this role. In this case the self builder has no legal duties beyond the appointment of Principal Designer and Principal Contractor.
  3. The self builder employs a contractor to carry out construction work, and then appoints that contractor as Principal Contractor for the duration of the project, because there is, or is likely to be, more than one contractor involved in the project. The emphasis will be on the co-ordination and management of the construction phase. In this case the self builder again has no legal duties beyond the initial appointments of Principal Designer and Principal Contractor.
  4. The self builder acts as their own project manager, employing individual trades at different times. In this instance, the self builder steps out of the DIY arena, because they are taking control of construction work. Where a self builder controls the way in which construction work is carried out by a person at work, they must comply with all the matters outlined in Part 4 of CDM 2015. This requirement is set out in Regulation 16 of CDM 2015, which effectively replaces Reg 26 in CDM 2007, this is not a new requirement. In this scenario the self builder will in effect become a contractor. In this case the HSE will expect self builders to demonstrate sufficient health and safety capability to meet the requirements of Part 4 of CDM 2015. Individual contractors will be expected to be able to advise the self builder on any specialist matters within their own work activities. The expectation on a self builder in this position will be on co-ordination and management , not on direct supervision of contractors on site. The self builder is entitled to expect contractors to plan, manage and monitor their own work in compliance with the CDM Regulations.


Not following CDM 2015 regulations could result in a dangerous, or even fatal, accident during the completion of your self build or custom build project. Furthermore, your finished home may not be safe to live in.

Building your own home can be risky. According to the Health and Safety Executive (HSE), around a third of all workplace fatalities occur in construction and many thousands are injured each year.

Breaching health and safety legislation when building your own home could mean that construction work might need to be stopped by the HSE or your local authority. Further work to the project might be needed to fix any problems. Most importantly, you may be liable for prosectution in some serious cases.

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