Essential CDM 2015 Regulatory Guides UK for Construction Projects

Before your last construction project started on site — did you read the Construction Phase Plan? Not skim it. Actually read it.

The client assumed their architect was "handling CDM." No written appointment had been made. Then HSE visited. This is an anonymised account of a situation we encounter more often than we should.

"It's only a small job. CDM doesn't apply to us." One of the most persistent myths in UK construction — and there is no size threshold that removes your client duties.

Under CDM 2015, the client is not a passive commissioner. They are a duty holder. That distinction matters. It means the client cannot simply hand the project to a contractor and step back.

Regulation 4 of CDM 2015 is four paragraphs long. Most clients have never read it. Those four paragraphs create the entire framework of client duty under the regulations. And they are more demanding — and more specific — than most clients realise.

"We're a domestic client — so the regulations don't really affect us." Not quite. CDM 2015 does treat domestic clients differently. But the regulations don't disappear. They transfer.

When did you last properly check the competence of a contractor — not just their insurance certificates and CSCS cards? Regulation 8 of CDM 2015 requires every duty holder to take reasonable steps to verify the skills, knowledge, experience, and organisational capability of those they appoint.

One of the most common questions we get asked is: "We've appointed a CDM consultant — are we covered now?" The short answer is no.

You have used the same contractor for three projects. You trust them. You know their team. Under CDM 2015, that is not the same as having checked their competence for this project.

The Principal Designer is the most misappointed role in CDM 2015. Either it is not appointed at all. Or it is appointed too late. Or it is appointed to someone without the skills and influence to perform it effectively.

Can the Principal Contractor just delegate the role and walk away from the liability? No. It is a question we hear from contractors and clients alike.

Designers have CDM 2015 duties before anything reaches a drawing. Regulation 9 requires health and safety to be an integral part of the design process.

Pre-construction information is not a nice-to-have. It is a legal duty. Many clients treat it as paperwork the contractor sorts out. The regulations say the opposite.

When did you appoint your Principal Designer — at concept, or once the drawings were already done? Timing is where most client compliance gaps begin.

On a Design and Build contract, who is responsible for design compliance? Most clients get this wrong. The assumption is simple: the contractor takes the design, so the contractor takes the duty.

The job stopped at 9am. Not by choice — by order. A commercial client engaged a contractor for a phased refurbishment of an occupied building.

Don't appoint a Principal Contractor, and the role doesn't disappear. It lands on you. This is one of the least understood consequences in CDM 2015.

Regulation 8 of CDM 2015 uses a four-part test for competence. Most clients only check one of the four.

A CDM breach is not a fine on a balance sheet. For individuals, it can mean prison. Compliance gets treated as a commercial risk. The regulations treat it as a criminal one.

Most clients receive the Health and Safety File at handover, file it, and never think about it again. That is the mistake.