, Building
A builder in Bolton takes on a loft conversion and a rear extension for a couple who have never had work done before. He brings in a roofer, a bricklayer, a sparks and a plumber. Nobody signs anything beyond his quote. Six weeks in, the couple ask why there is no toilet on site and whether the neighbours can walk under the scaffold.
He is, in law, the principal contractor, the principal designer if nobody else has been appointed in writing, and he has inherited most of the duties his clients never knew they had. He is also required to have written a construction phase plan before work started, and he has not.
CDM 2015 gave everyone a named job
The Construction (Design and Management) Regulations 2015 came into force on 6 April 2015 and replaced the 2007 version. The change people remember is that the CDM coordinator was abolished and the principal designer took its place, sitting inside the design team rather than alongside it. The change that matters more is that the regulations stopped applying only to large or notifiable projects and started applying, in some form, to everything.
The duty holders are these. The client, who commissions the work and who must make suitable arrangements for managing it. The principal designer, who plans, manages and monitors the pre-construction phase and coordinates health and safety in design. The principal contractor, who does the same for the construction phase. Designers and contractors, who carry their own duties. And workers, who must be consulted and must be given the information they need.
The two principal roles only exist where there is more than one contractor. In practice that threshold is crossed by almost every job with a subcontracted trade on it. One builder and one electrician is more than one contractor. A client who does not make the appointments in writing does not thereby avoid the duties: under regulation 5, the client is treated as having taken them on, and on a domestic job those duties move again, which is covered below.
The obligation people most often miss is the construction phase plan. Under regulation 12, a construction phase plan is required for every project, not only the large ones. For a small job it is not a document that needs binding. It is a few pages that say what is being built, the sequence, the site rules, the significant risks and how they are being controlled, who is doing what, and the arrangements for welfare and for emergencies. It has to exist before construction begins and it has to be kept current.
Welfare is the other one. Schedule 2 sets out sanitary conveniences, washing facilities, drinking water, changing and rest facilities. On a domestic extension that usually means an agreement in writing about the use of the house, or a hired welfare unit. The absence of any arrangement is the failure, not the absence of a unit.
Notifiable is a threshold, not a standard
A project is notifiable to the Health and Safety Executive if the construction work is scheduled to last longer than 30 working days and have more than 20 workers working simultaneously at any point, or if it is scheduled to exceed 500 person days. Notification is made on form F10, by the client, before the construction phase begins, and a copy has to be displayed in the site office where workers can read it.
Two things about that threshold are regularly misunderstood.
The first is that it is an "and", not an "or", on the first limb. Thirty-five working days with four people on site is not notifiable on that test, though it may be on the 500 person day test. Work the arithmetic rather than assuming.
The second is that notification changes nothing about your duties. Every other requirement in CDM applies whether or not the F10 is sent. The construction phase plan, the appointments, the welfare, the information and the health and safety file all apply to a two week job. Notification is a letter to the regulator, not a quality threshold, and treating "not notifiable" as "not covered" is the single most common misreading of these regulations.
Domestic clients pass their duties to you, by default
Regulation 7 is the one every small builder should know by heart.
A domestic client is someone having construction work done on their own home, or on the home of a family member, that is not connected with a business. They are not exempt from CDM. Instead, their client duties pass automatically to someone else.
Where there is only one contractor, the duties pass to that contractor. Where there is more than one, the duties pass to the principal contractor. They can instead pass to the principal designer, but only if there is a written agreement to that effect between the principal designer and the client. Failing all of that, if the domestic client has appointed a designer who is in charge of the design, that designer is treated as the principal designer.
The practical effect is that on a typical house extension the builder is holding three sets of duties at once and is being paid for one of them. That is not a reason to grumble. It is a reason to write it down, allow for it in the price, and be explicit with the client about what you are taking on and what you need from them, particularly information about the building: asbestos, services, structure, anything they know about previous work.
There is a second layer for anyone working on housing and other buildings in England. The Building Safety Act 2022 brought in a dutyholder regime under the Building Regulations from 1 October 2023, with client, principal designer and principal contractor roles that sit alongside the CDM ones but are about compliance with the Building Regulations rather than about health and safety. They are different appointments with similar names. Appointing the same people to both is common and sensible; assuming they are the same duty is not. As always with a regime this new, check the current position rather than relying on a summary.
The paperwork that is actually worth keeping
CDM generates documents that can be either a defence or a liability, depending on whether they describe the site.
Keep the construction phase plan current. If the sequence changes, the plan changes. A plan written on day one and never touched again is evidence that you were not managing the phase.
Keep the pre-construction information you were given, and keep a note of what you asked for and did not get. If you asked the client for an asbestos survey and they declined, that record matters.
Keep the health and safety file for projects with more than one contractor. It is a file for whoever maintains or alters the building afterwards: what is in the structure, where the services run, what was left in place. On a small job it can be a folder of as-built drawings, product data and a list of the unusual things.
Keep the induction and briefing records. Not a training industry's worth, just a signed sheet showing who was inducted on what date and what they were told.
If the HSE turns up after an incident, the question will not be whether you had a system. It will be whether the site looked like the system.
Where this shows up in the game
Construction arrives in Business Baron with the Property & Construction Track, an add-on to the full game. Health and safety is a slow variable rather than an event, and neglect raises the chance of an incident that costs wages, an insurance excess and a visit from the authorities. Standing duties cost time on every job, whether or not anybody checks.