The Health and Safety File Under CDM 2015 — A Trade's Guide (2026)

What is the Health and Safety File?

The Health and Safety File is a record of information for the client and any future end user about the completed structure. Its purpose is simple but important: it gives whoever owns or occupies the building the information they need to plan and carry out future work safely. That means future construction, cleaning, maintenance, alteration or eventual demolition.

Think of it as the building's safety memory. When someone comes back in five, ten or twenty years to refurbish a roof, drill into a wall or take a structure down, the file tells them what was built, what residual hazards remain, and what they need to know to avoid being hurt. It is handed to the client at the end of the project and stays with the building for its life.

When is a Health and Safety File required?

A file is only required for projects involving more than one contractor. If you're a sole trader carrying out the whole job yourself — a single contractor with no others on site — CDM 2015 does not require a Health and Safety File for that project.

As soon as there is more than one contractor working on the project, the duties around the file are triggered, along with the wider requirement to appoint a Principal Designer and a Principal Contractor. Many domestic and small commercial projects involve multiple trades — a builder, an electrician, a plumber, a roofer — so the threshold is crossed more often than people assume. If in doubt, count the contractors. Two or more, and a file is needed.

Who prepares the file?

The Principal Designer (PD) prepares the Health and Safety File. The PD's role runs through the project: they prepare the file, review it as the work develops, and update it whenever the design or construction changes in a way that affects future safety. At the end of the project, the PD hands the completed file to the client.

There's an important handover rule. If the Principal Designer's appointment ends before the project finishes — which is common, because design work often wraps up before construction does — responsibility for the file passes to the Principal Contractor (PC). The PC then maintains and completes the file through to handover. This avoids the file falling into a gap when the PD leaves site.

Every contractor and designer on the project has a part to play. You should pass relevant information about your part of the work — residual hazards, materials used, anything that affects future maintenance — to the PD or PC so it can go into the file. The file is only as good as the information feeding it.

What should the file contain?

The content should be relevant to the people who will use it in future and proportionate to the risks. The Health and Safety File should include:

• A description of the works carried out — what was built or altered, in plain terms
• Residual hazards and how they have been dealt with — for example asbestos left in place, contaminated land, buried services or fragile roofs
• Key structural principles — load-bearing elements, bracing, and safe working loads for floors, roofs and other areas, especially where these are not obvious
• Hazardous materials used — specific finishes, coatings, paints, sealants or insulation that future workers need to be aware of
• Information on the services and utilities installed — gas, water, electrical and drainage, including emergency isolation points
• Equipment provided for cleaning or maintaining the structure — fall-arrest anchor points, access cradles, roof walkways and similar
• The nature and location of significant services, including underground and concealed runs
• As-built drawings, plus details of the plant and equipment installed

The test for each item is straightforward: would someone planning future construction, cleaning, maintenance, alteration or demolition need to know this to do the job safely? If yes, it belongs in the file. If it's only relevant during the build itself, it usually doesn't.

What should the file NOT contain?

A common mistake is treating the file as a dumping ground for every piece of project paperwork. An overstuffed file is worse than a lean one — the genuinely important safety information gets buried. Keep it relevant and proportionate. The file should not include:

• The Construction Phase Plan — that document manages safety during construction and has done its job by handover
• General risk assessments and method statements for the construction work itself
• Contract details, pricing, programmes and other commercial paperwork
• Pre-tender information, names of contractors, or routine correspondence that has no bearing on future safety

If a document only mattered while the building was being constructed, it doesn't belong in the file. Strip it back to what a future occupier or contractor genuinely needs.

The CDM "golden thread" — how the file relates to other documents

The Health and Safety File doesn't exist in isolation. CDM 2015 runs three key documents in sequence, sometimes called the golden thread of information:

• Pre-Construction Information (PCI): gathered by the client and developed by the Principal Designer at the start. It tells the team what is already known about the site and existing structure before work begins.
• Construction Phase Plan (CPP): prepared by the Principal Contractor. It sets out how health and safety will be managed during the build itself.
• Health and Safety File: the output at the end. It captures the residual safety information about the finished structure for future use.

Information flows along this thread. Hazards identified in the PCI that remain after construction should be carried through and recorded in the file. The CPP manages the live risks during the build; the file records what's left behind for whoever comes next. Done well, the three documents tell a continuous story from "what we knew" to "what we did" to "what you need to know now".

The client's duty to keep the file

Once the file is handed over, the responsibility shifts to the client. Under CDM 2015 the client must keep the Health and Safety File available for anyone who needs it to comply with health and safety law — for example a contractor brought in to do future maintenance or alteration work.

Crucially, if the client sells the building, they must pass the file on to the new owner. The file follows the structure, not the original client. This is what makes it useful decades later: a building changing hands several times still carries its safety record with it, provided each owner honours the duty to keep and pass it on.

Where future work is carried out on the structure, the file should be reviewed and, if necessary, updated to reflect what has changed. A file that is never updated slowly drifts out of date and loses value.

What the Health and Safety File should include — checklist

Practical tips for trades

• Feed information as you go. Don't wait until handover to remember what went into the building. Pass residual hazards, materials and as-built changes to the PD or PC while they're fresh.
• Keep it lean. A focused file that someone can actually read beats a ring binder full of irrelevant paperwork. If an item won't help future safe working, leave it out.
• Confirm who holds the pen. On longer projects, check whether the Principal Designer or Principal Contractor is responsible for the file at any given stage — responsibility moves to the PC if the PD leaves early.
• Use as-built drawings, not design drawings. Future workers need to know what's actually there, including any changes made on site, not just what was originally drawn.
• Flag concealed risks clearly. Buried services, hidden steelwork, treated timbers and special coatings are exactly the things that hurt people years later. Make them obvious in the file.
• Remind the client of their duty. Many clients don't realise they must keep the file and pass it on if they sell. A short note at handover protects everyone.

Getting the file right

The Health and Safety File is one of the more practical parts of CDM 2015. Stripped of jargon, it's simply the safety information the next person needs to work on the building without getting hurt. Get the basics right — only required where there's more than one contractor, prepared by the Principal Designer (or the Principal Contractor if the PD leaves first), focused on residual risks and future safe working, and kept by the client for the life of the structure — and you'll satisfy the regulations without drowning in paperwork. When everyone on the project understands their part, the file does what it's meant to do: keep people safe long after the scaffolding comes down. As always, this is general guidance and not a substitute for legal advice on your specific project.