Pre-Construction Information: A CDM 2015 Guide

Pre-construction information is the first compliance document on any UK construction project — and the one most often misunderstood. It is the client's job to provide it, not the contractor's job to chase it. Yet on a great many projects it arrives late, arrives thin, or never arrives at all, and the principal contractor ends up building a construction phase plan on guesswork.

This guide explains what pre-construction information actually is under the Construction (Design and Management) Regulations 2015, who is legally responsible for providing it, what it must contain, and how it connects to the other two CDM documents — the construction phase plan and the health and safety file. You can also download our free CDM document pack template, which includes a pre-construction information starter structure.

What pre-construction information is

Pre-construction information (often shortened to "PCI") is the package of health and safety information a client gathers and hands to the people designing and building a project, so that they can plan and carry out the work safely. It is one of the three core information flows that run through CDM 2015: pre-construction information at the start, the construction phase plan during the build, and the health and safety file at the end.

The Construction (Design and Management) Regulations 2015 (SI 2015/51) define pre-construction information in Regulation 2 as:

"information in the client's possession or which is reasonably obtainable by or on behalf of the client, which is relevant to the construction work and is of an appropriate level of detail and proportionate to the risks involved."

Two things stand out in that definition. First, it is information the client already holds or can reasonably get hold of — not information the client has to invent. Second, it must be proportionate: a domestic loft conversion needs far less than a city-centre refurbishment with live services and an asbestos register.

The definition goes on to set out, in broad terms, what the information covers:

details of the project, its planning and management, and the health and safety hazards involved — including the design and construction hazards and how they will be addressed; and
any information in an existing health and safety file from previous work on the same structure.

That last point is the link backward in the document chain: if a building already has a health and safety file from earlier construction work, the relevant parts of it become pre-construction information for the next project.

Who must provide pre-construction information

This is the part that catches people out. Under CDM 2015 the duty sits squarely with the client, not the contractor and not the designer. Regulation 4(4) states:

"A client must provide pre-construction information as soon as is practicable to every designer and contractor appointed, or being considered for appointment, to the project."

Read that carefully, because there are three practical consequences:

The client provides it. A client cannot delegate this duty away by assumption. On most commercial projects the client appoints a principal designer who collates and issues the information on the client's behalf, but the legal duty remains the client's.
It goes to everyone being appointed — including those only being considered. Designers and contractors need the information to price and plan the work accurately, which means it has to reach them during the tender or appointment stage, not after they start.
"As soon as is practicable." The information must be provided early enough to be useful. Pre-construction information that lands the week before work starts has missed its purpose — the whole point is to inform design and planning decisions before they are locked in.

For domestic clients (someone having work done on their own home, not in connection with a business), CDM 2015 transfers most client duties to the contractor or principal contractor automatically, so in practice the contractor takes on the information-gathering role.

What pre-construction information must contain

CDM 2015 does not prescribe a fixed template. HSE's guidance L153 ("Managing health and safety in construction") sets out what good pre-construction information looks like in practice, scaled to the project. A solid pre-construction information pack typically covers:

1. Project description and programme

What is being built, where, the intended use, the programme, and the key dates. This frames everything that follows.

2. The client's considerations and management requirements

The client's arrangements for managing the project — how the client will check that duty holders are doing their jobs, communication arrangements, and any site rules the client wants applied (for example, an occupied building that must stay operational during the works).

3. Environmental restrictions and existing on-site risks

This is the heart of the document. It includes:

Boundaries and access — neighbouring occupiers, restrictions on working hours, traffic management.
Existing services — live electrical, gas, water, and drainage runs; overhead and underground services.
Existing structures — condition, stability, and any structural information needed before demolition or alteration.
Hazardous materials — most importantly the asbestos survey or register where the building predates the year 2000, plus contaminated land, lead paint, and similar.
The site's history and surroundings — previous use, ground conditions, and anything that affects how the work can be done safely.

4. Significant design and construction hazards

The hazards that are already known — for example a fragile roof, a confined space, or a structure that can only be dismantled in a particular sequence — and the principal design assumptions about how they will be managed.

5. Existing health and safety file

Where one exists from previous construction work, the parts of it relevant to the new project.

The level of detail in each section is proportionate to the risk. The test is simple: would a competent designer or contractor have what they need to plan the work safely without having to guess?

How pre-construction information connects to the other CDM documents

Pre-construction information does not sit on its own. It is the first link in a chain:

Pre-construction information (client → designers and contractors) sets out what is known about the site and its hazards before design and construction begin.
The construction phase plan (drawn up by the principal contractor) takes that information and turns it into a plan for managing health and safety during the build. A construction phase plan built without proper pre-construction information is a plan built on assumptions — which is exactly the failure CDM is designed to prevent.
The health and safety file (prepared by the principal designer) captures the information that future projects on the structure will need — and feeds back in as pre-construction information next time round.

For the principal contractor's side of that chain, see our guide to the construction phase plan. For the duty-holder map that explains who is responsible for each document, see CDM principal contractor duties.

Common pre-construction information failures

In practice, the recurring problems are predictable:

It arrives too late. Provided after appointment rather than during, so it cannot influence pricing or planning.
It is generic. A boilerplate document with no site-specific hazard information — which is no better than no information at all.
The asbestos position is missing. For any building constructed or refurbished before 2000, the asbestos survey or register is the single most important piece of pre-construction information. Its absence is a common and serious gap.
Nobody owns it. The client assumes the designer is handling it; the designer assumes the client provided everything; the contractor receives a thin pack and builds the construction phase plan on guesswork.

The fix is ownership and proportionality: someone (usually the principal designer, acting for the client) is responsible for collating real, site-specific information and issuing it early enough to matter.

Bottom line

Pre-construction information is a client duty under Regulation 4(4) of CDM 2015. It must be provided to every designer and contractor — including those being considered for appointment — as soon as is practicable, and it must be proportionate to the risks of the project. Get it right and the construction phase plan that follows is built on facts; get it wrong and every document downstream inherits the gap.

For a starting structure covering both pre-construction information and the health and safety file, download our free CDM document pack template.

Sources

This guide is for informational purposes and does not constitute legal advice. For project-specific CDM duties, consult your CDM advisor or principal designer. Last reviewed against CDM 2015 (SI 2015/51) on 2026-06-04.