Construction compliance guide
What Is a Health and Safety File in Construction? Complete UK Guide
Everything you need to know about the CDM 2015 health and safety file — what goes in it, who creates it, when to hand it over, and why it matters long after the project is finished.
TL;DR
- • The health and safety file is a CDM 2015 requirement for projects with more than one contractor.
- • It is a permanent record of information needed for future maintenance, alteration, or demolition of the building.
- • The principal designer creates it; the client keeps it for the life of the building.
- • It is not the same as a construction phase plan — the CPP is for during the build, the H&S file is for afterwards.
- • Contents include as-built drawings, residual hazards, structural details, and maintenance information.
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What is a health and safety file?
A health and safety file is a permanent collection of information about a building or structure that anyone carrying out future construction work will need. It records how the building was built, what materials were used, where the hidden hazards are, and what maintenance is needed to keep it safe.
Think of it as the building’s medical record. Just as a doctor needs your history before treating you, a builder working on a building in the future needs to know what is behind the walls, under the floors, and above the ceilings before they start disturbing anything. The health and safety file provides that information.
The concept was first introduced under the original CDM Regulations in 1994. The current requirement comes from Regulation 12(5) of the Construction (Design and Management) Regulations 2015 (CDM 2015). The HSE provides specific guidance in their CDM 2015 health and safety file guidance.
What does the law say?
CDM 2015 Regulation 12(5) states that the principal designer must prepare a health and safety file for the project. The file must contain information relating to the project that is likely to be needed during any subsequent project to ensure the health and safety of any person. For a full overview of CDM 2015, see our What is CDM? guide.
The key legal duties are:
- The principal designer must prepare, review, update, and revise the file during the project.
- The principal designer must pass the file to the client at the end of the project (or to the principal contractor if the principal designer’s appointment ends first).
- The client must keep the file available for inspection by anyone who needs it for future construction work.
- If the property is sold or transferred, the file must go with it.
- When further construction work is carried out on the building, that project’s duty holders revise the file to add the new information.
There is no prescribed format. The regulations do not say it must be a ring binder, a PDF, or a cloud-based system. What matters is that it exists, it contains the right information, and it is accessible when needed.
What goes in a health and safety file?
CDM 2015 does not provide an exhaustive list, but the HSE guidance and Regulation 12(5) make clear that the file should contain information about the current project that is likely to be needed to ensure health and safety during any subsequent work. In practice, this means:
As-built drawings and plans
Accurate drawings showing the building as it was actually constructed, not just the original design drawings. These should show the location of structural elements, foundations, drainage, services (gas, water, electricity, data), fire protection systems, and any features that differ from the original design.
Residual hazards and risks
Information about any hazards that remain in the building after construction is complete. This includes asbestos-containing materials, contaminated land beneath the foundations, fragile roof materials, areas where work at height is required for maintenance, and any other hazard that a future worker needs to know about.
Structural details
Information about the structural design, including load-bearing walls, steelwork connections, pre-stressed or post-tensioned concrete elements, and any structural limitations. Anyone working on the building in the future needs to know which walls they cannot remove and what loads the structure can bear.
Services and utilities
Location and routing of all services — gas, water, electricity, telecoms, drainage, and any specialist systems. This is critical safety information. Builders have been killed by accidentally cutting into live services that were not shown on any available drawings.
Maintenance information
Details of any equipment or features that require ongoing maintenance, how that maintenance should be carried out safely, and what access provisions have been made. For example: how to safely access the roof for gutter cleaning, what PPE is needed for maintaining mechanical plant, or how to isolate electrical systems for inspection.
Materials and products used
Information about key materials used in the construction, particularly those that might present hazards during future work — treated timber, specialist coatings, insulation types, waterproofing membranes, and any products with specific handling or disposal requirements.
The file should only contain information that is useful for future health and safety purposes. It is not a general project archive — do not fill it with every email, every order confirmation, or every site photograph. Keep it focused and relevant.
Who creates and maintains the health and safety file?
The principal designer is the dutyholder responsible for creating the health and safety file. On most commercial projects, the principal designer is the architect or lead design consultancy. On smaller projects, it might be a structural engineer or even the client’s agent.
However, the principal designer cannot create the file alone. They need information from other parties, particularly the principal contractor and other designers and contractors. This means:
- Contractors must provide as-built information, product data sheets, and details of any changes made during construction that differ from the original design.
- Specialist subcontractors (steelwork fabricators, M&E installers, piling contractors) must provide relevant technical information about their installations.
- The principal contractor must cooperate with the principal designer in gathering this information and must take over the file if the principal designer’s appointment ends before the project is complete.
- Designers must provide information about residual design risks that will affect future work on the building.
If you are a builder working as a subcontractor on a project, you will likely be asked to provide information for the health and safety file. This is a legal expectation — cooperate promptly and provide accurate, useful information.
When do you hand it over?
The health and safety file must be handed to the client at the end of the project. In practice, “the end of the project” usually means practical completion — when the building is ready for occupation or use.
The principal designer should not wait until the last day to start compiling the file. The file should be built up throughout the project as information becomes available. Waiting until handover to gather everything typically results in missing information, because subcontractors have left site and moved on.
If the principal designer’s appointment ends before the project is finished (which sometimes happens on phased projects or when there is a change of designer), they must pass the file to the principal contractor. The principal contractor then takes on the duty to maintain and update the file until it can be handed to the client at the end of the project.
On some projects, particularly larger ones, the file may be handed over in stages — for example, when individual buildings or phases are completed. The important thing is that the client receives the relevant information before they take responsibility for the completed structure.
How does it differ from a construction phase plan?
This is one of the most common areas of confusion in CDM 2015. The construction phase plan (CPP) and the health and safety file serve entirely different purposes:
Construction phase plan (CPP)
A live document used during the construction phase to manage health and safety on site. It covers the arrangements for managing the project, the specific risks of the work, and the control measures being used. Where there is more than one contractor, the principal contractor creates and maintains the CPP; where there is only one contractor, that contractor does under regulation 15(5). It is a working document that changes as the project progresses.
Health and safety file
A permanent record for the future. It contains information about the completed building that will be needed by anyone carrying out subsequent construction work, maintenance, cleaning, alteration, or demolition. The principal designer creates it. It stays with the building for its entire life.
A simple way to remember: the CPP asks “how do we build it safely?” and the H&S file asks “how do we work on it safely in the future?” Both are important, but they are different documents with different purposes, different authors, and different audiences.
What happens to the file after the project?
Once the client receives the health and safety file, it becomes their responsibility. CDM 2015 places clear duties on the client:
- Keep the file available for inspection by anyone carrying out future construction work on the building.
- When further construction work is done, make sure that project’s duty holders add its relevant information to the existing file — the revision duty for that work sits with them.
- Pass the file on if the building is sold, leased, or otherwise transferred to a new owner.
- Make the file available to the principal designer and principal contractor of any future project, so they can use it to plan and manage the work safely.
In reality, many health and safety files are handed over in a ring binder, put on a shelf, and never looked at again until the next major refurbishment. This is a wasted opportunity. A good H&S file spares future projects repeated investigation because designers and contractors do not have to dig for what is behind every wall or under every floor from scratch.
Do domestic projects need a health and safety file?
If a domestic project involves more than one contractor, CDM 2015 applies in full, which means a health and safety file is required. However, on domestic projects, the client’s duties (including keeping the H&S file) transfer away from the domestic client — by default to the contractor if there is only one contractor or to the principal contractor if there is more than one contractor, or, where there is more than one contractor, instead to a principal designer if there is a written agreement to that effect. For more detail on how CDM applies to homeowners, see our domestic client CDM guide.
For a typical domestic extension or loft conversion with multiple trades involved, you should produce a simple health and safety file and hand it to the homeowner at the end of the project. Explain what it is and why they should keep it. Include the key items — as-built drawings, structural engineer’s details, information about materials used, and any residual hazards (such as the location of buried drainage or the presence of a steel beam above a new opening).
Even on single-contractor domestic jobs where it is not strictly required, providing a basic H&S file is good practice. It demonstrates professionalism, protects future tradespeople, and adds value for the homeowner. It does not need to be elaborate — a folder with the structural calculations, service locations, and a note about any hazards is usually sufficient.
Health and safety file contents checklist
Use this checklist as a starting point. Not every item will apply to every project, and some projects will require additional information not listed here. The key question to ask for each piece of information is: “Would someone carrying out future work on this building need this to do the job safely?”
- A brief description of the work carried out, including the design principles and materials used.
- As-built drawings and site plans showing the structure, foundations, drainage, and services as actually constructed.
- Structural engineer’s calculations and details, including load-bearing elements and any design limitations.
- Details of all services and utilities: routing, connection points, isolation procedures, and any hazardous energy sources.
- Information about residual hazards: asbestos, contaminated ground, fragile materials, confined spaces, live services, or any other hazard that is not immediately obvious.
- Maintenance procedures for any installed equipment (lifts, HVAC systems, fire suppression, lightning protection, etc.) including safe access requirements.
- Details of materials used that may be hazardous during future work: treated timber, specialist insulation, lead-based coatings, or composite materials.
- Fire safety information: fire compartmentation details, fire-stopping locations, smoke ventilation systems.
- Waterproofing and tanking details where applicable.
- Any specialist information from subcontractors (piling records, steelwork fabrication details, cladding system specifications).
- Manufacturer’s operation and maintenance manuals for installed equipment.
- Certificates and test results: structural, electrical, gas, fire alarm, lightning protection.
Common problems and how to avoid them
Health and safety files are one of the most neglected aspects of CDM 2015. Here are the problems that come up most often:
Left until the last minute
If you wait until handover to start compiling the file, you will struggle to get information from subcontractors who have already left site. Start building the file from day one. Request as-built information and product data as each phase of work is completed, not after the scaffolding comes down.
Too much irrelevant information
A health and safety file crammed with every site diary entry, every email, and every delivery note is useless. Future users need to find the relevant information quickly. Keep it focused on information that is genuinely needed for future health and safety purposes.
Missing as-built drawings
The original design drawings are not the same as as-built drawings. Services get rerouted, structural details change, and design amendments happen during construction. The file must show the building as it was actually built. Insist on marked-up or redrawn as-built drawings before accepting the file as complete.
Not explaining residual hazards clearly
Simply listing "asbestos" is not helpful. Where exactly is it? What type? What condition is it in? What should someone do before disturbing it? The file should be written so that a competent builder who has never seen the building before can understand the risks.
Lost after handover
Paper files get lost, misfiled, or thrown away during office moves. Digital files stored on a single computer are vulnerable to hardware failure. Use a cloud-based system or at minimum provide copies in multiple formats and locations. Advise the client on their duty to keep the file and pass it on.
Digital and paper file formats
CDM 2015 does not prescribe a format. A digital health and safety file can be searched, shared, updated and stored without relying on a single paper copy. A cloud copy can be shared with future designers, contractors and building owners when needed.
If you do provide a paper file, consider also providing a digital copy on a USB drive or via a shared cloud folder. Make sure all drawings are legible at the printed size — an A0 drawing reduced to A4 is often unreadable. For digital files, use widely accessible formats like PDF for documents and DWG or PDF for drawings.
Using a project management tool like The Site Book keeps the documents you control — RAMS, drawings, safety data sheets, certificates — stored and retrievable in one place. That is a useful start, but the health and safety file is not just a bundle of your own paperwork: the principal designer compiles it from information that also comes from others, such as as-built drawings, residual hazards and maintenance details, so expect to collect material from beyond your own filing before handover.
Practical tips for builders
Whether you are creating a health and safety file or contributing to one, these practical tips will help you get it right:
- Take photographs of services, structural elements, and hidden features before they are covered up. A photo of drainage before backfilling is worth a thousand words.
- Record any deviations from the design drawings as they happen. Do not rely on memory six months later when the principal designer asks for as-built information.
- Use clear, plain English in all descriptions. The person reading the file in 20 years’ time will not know the project or the people involved. Avoid jargon, abbreviations, and references to conversations or decisions that are not recorded in writing.
- Include contact details for specialist installers where ongoing maintenance is required (e.g. the company that installed the fire suppression system or the structural engineer who designed the steelwork).
- If you are working on an existing building and there is already a health and safety file, add your project’s information to it rather than creating a separate document. The file should grow with the building.
- Make sure any drawings or documents you provide are clearly labelled with the project name, date, author, and revision number.
Frequently asked questions
Is a health and safety file required for every construction project?
Under CDM 2015, a health and safety file is required for every project that involves more than one contractor. For projects with only one contractor, the regulations do not specifically require a health and safety file, although it is still considered good practice to compile one — especially for projects that alter the structure of a building or introduce residual hazards that future workers or occupants need to know about. If a principal designer has been appointed, they must prepare or update the health and safety file. The file must contain information likely to be needed during any subsequent construction work, including cleaning, maintenance, alteration, or demolition.
Who is responsible for creating the health and safety file?
The principal designer is responsible for preparing the health and safety file as soon as practicable after their appointment, and for keeping it reviewed, updated and revised as the work progresses. Single-contractor projects have no principal designer — and no file requirement at all (see above). Where there is more than one contractor but no principal designer has been appointed, the fallback depends on the client: on a domestic project, the designer in control of the pre-construction phase is treated as the principal designer (regulation 7(2)); on every other project, the client must carry out the principal designer's file duties itself (regulation 5(3)). Once the project is complete, the principal designer must pass the file to the client. If the principal designer’s appointment finishes before the project is complete, they must pass the file to the principal contractor, who then takes on responsibility for maintaining it until handover to the client.
What is the difference between a health and safety file and a construction phase plan?
They serve completely different purposes. A construction phase plan (CPP) is a live working document used during the construction phase to manage health and safety risks on site. It covers how the project will be managed, the specific risks, and the arrangements for controlling them. The health and safety file, by contrast, is a permanent record intended for future use — it contains information that anyone carrying out subsequent work on the building will need. Think of the CPP as the instruction manual for building it safely now, and the H&S file as the maintenance manual for working on it safely in the future. The CPP is discarded or archived after the project; the H&S file stays with the building for its entire life.
What happens to the health and safety file after handover?
Once the client receives the health and safety file, CDM 2015 keeps one duty running: the file must be kept available for inspection by anyone who may need it to comply with legal requirements (regulation 4(5)(b)(iii)) — and if the client sells or otherwise disposes of their interest in the building, they comply with that duty by handing the file to whoever acquires it and making sure that person understands its nature and purpose (regulation 4(7)). Beyond that, keeping the file for the life of the building is HSE-recommended good practice rather than a statutory rule, and when further construction work is carried out it is that project's duty holders who review the file and add the new information to it. On domestic projects these client-side duties transfer to the contractor if there is only one contractor, or to the principal contractor if there is more than one contractor, under regulation 7(1) — or, where there is more than one contractor, instead to a principal designer who has agreed in writing to take the client duties. In practice, many H&S files are lost or forgotten after handover, which creates problems for future projects.
Can a health and safety file be digital?
Yes, absolutely. CDM 2015 does not specify a format. A digital health and safety file can be searched, shared, updated, and stored securely without relying on a single paper copy. A cloud copy can be shared with future contractors, designers, and building owners when needed. The key requirement is that the file is kept available for inspection — a digital format meets this requirement as long as it is accessible and can be produced when needed.
What if the previous health and safety file has been lost?
This is unfortunately common, especially with older buildings. If you are working on a building and the existing H&S file cannot be found, you should make every effort to gather the information it should contain — check with the building owner, previous designers, local authority building control records, and any available as-built documentation. For the current project, the principal designer must create a new health and safety file that captures all relevant information about the work being carried out. Going forward, the client should be advised of their duty to keep the file safe and pass it on with any future sale of the property.
How The Site Book helps
- • All project documents stored in one place — RAMS, drawings, certificates, and safety data sheets.
- • Document sharing — export or share your stored project documents when it is time to hand information over.
- • Compliance dashboard shows the status of every document, so nothing gets missed.
- • Cloud-based storage keeps your project documents retrievable in one place — the file itself stays with the client for the life of the building.
Health and Safety File — why it matters after the job ends
Pros
- The H&S file is the ONE document that survives to the next contractor — good data here prevents accidents in year-10 maintenance.
- Only required on multi-contractor projects, so small single-contractor domestic jobs are automatically out of scope.
- You only need information 'relevant to future construction, maintenance, demolition' — not every RAMS from the whole job.
- A clean H&S file at handover is a professional signal — it gets you recommended for bigger projects.
Cons
- Mixing CPP content into the H&S file creates a messy 500-page document nobody can use later.
- Skipping the H&S file on a multi-contractor project is a CDM 2015 breach - reg 12 makes the file a legal duty, not paperwork theatre.
- The client owns the file at handover — lose it and the next refurb contractor has no information to plan around.
- File content that is too vague ('electrical services: various routes') is useless and not compliant.
| Item | H&S File | CPP |
|---|---|---|
| As-built drawings with service routes | Yes | No |
| Hazardous materials remaining in structure (asbestos, lead) | Yes | Yes (during works) |
| Structural engineering calcs for residual loads | Yes | No |
| Day-to-day site rules + PPE policy | No | Yes |
| Emergency procedures during the build | No | Yes |
| Named duty holders during construction | No | Yes |
| Maintenance strategy for fragile/high-level elements | Yes | No |
“…the principal designer must prepare a health and safety file appropriate to the characteristics of the project…”
Keep the information your H&S File needs in one place
The Site Book generates the CPP, RAMS and COSHH assessments for the construction phase, and stores the drawings, certificates and safety data sheets you will draw on when the dutyholder compiles the health and safety file. The file itself is compiled by the principal designer (or the PC once the PD’s appointment ends) — not generated automatically.
Related guides
What is CDM?
A complete guide to the Construction (Design and Management) Regulations 2015.
Principal Contractor Duties
What the principal contractor is responsible for under CDM 2015.
What is a Construction Phase Plan?
How to write a CPP and what it should contain.
Domestic Client CDM
How CDM 2015 applies when the client is a homeowner.
Keep all your project documents in one place.
The Site Book stores RAMS, drawings, certificates, and safety documentation — so the information you need at handover is easy to find. No credit card required.
Sources
- Principal Contractors — HSE · Accessed 17 April 2026
- CDM 2015, Regulation 12 — construction phase plan and health and safety file — legislation.gov.uk · Accessed 4 September 2026