Construction Phase Plan: The Complete UK Guide to CDM 2015 Compliance

A construction phase plan is one of the most important documents in UK construction. If your project falls under the Construction (Design and Management) Regulations 2015, you almost certainly need one.

Yet many contractors treat it as an afterthought — a document cobbled together the night before the pre-start meeting. That's a problem, because the construction phase plan is supposed to be the master document that keeps everyone on site safe.

This guide covers what a construction phase plan is, when you need one, who writes it, what goes in it, and how it connects to your RAMS documentation.

What Is a Construction Phase Plan?

A construction phase plan (CPP) is a document that sets out the health and safety arrangements, site rules, and specific measures for managing risks during the construction phase of a project.

Under CDM 2015, it's a legal requirement. Regulation 12 states that the principal contractor (or sole contractor on single-contractor projects) must draw up a construction phase plan before the construction phase begins.

The plan must be "proportionate to the nature and size of the project and the risks involved."

Think of it as the health and safety management plan for the entire site. Individual RAMS documents sit underneath it, covering specific tasks and activities.

When Do You Need a Construction Phase Plan?

Every construction project that falls under CDM 2015 needs a construction phase plan. This is a common misconception — many people think only notifiable projects need one.

CDM 2015 applies to all construction work in the UK. This means:

• A kitchen refurbishment? You need a construction phase plan.
• A new build house? You need a construction phase plan.
• Painting the outside of a building? You need a construction phase plan.
• Installing a new heating system? You need a construction phase plan.

The level of detail varies. A bathroom refit needs a proportionate, simple plan. A multi-storey apartment block needs a comprehensive document.

What Counts as "Construction Work"?

CDM 2015 defines construction work broadly. It includes:

• Building, alteration, fitting-out, commissioning, renovation, repair, upkeep, redecoration, maintenance
• Demolition and dismantling
• Installation, commissioning, maintenance, and removal of mechanical, electrical, gas, telecommunications, and similar services
• Site clearance, investigation, excavation, and ground preparation
• Assembly and disassembly of prefabricated structures

If in doubt: it's probably construction work.

Who Writes the Construction Phase Plan?

This depends on the project structure:

Projects with Multiple Contractors

The principal contractor must prepare the construction phase plan. They must do so before the construction phase begins.

The client must ensure a principal contractor is appointed in writing before the construction phase starts. If they don't appoint one, the client takes on the principal contractor duties — including writing the plan.

Single Contractor Projects

If there's only one contractor on the project, that contractor must prepare the construction phase plan. There's no principal contractor on single-contractor projects (that role only exists when multiple contractors are involved).

The Client's Role

The client doesn't write the plan, but they have duties:

• Ensure the plan is prepared before construction begins
• Provide pre-construction information (surveys, utility records, previous asbestos reports, site constraints)
• Ensure the plan is reviewed and updated as necessary

The Principal Designer's Role

The principal designer (or designer on single-contractor projects) provides design risk information that feeds into the construction phase plan. They don't write it, but their input is essential — particularly around residual design risks and assumptions.

What Goes in a Construction Phase Plan?

CDM 2015 Schedule 1 sets out the required contents. The plan must include:

1. Description of the Project

• Project name, address, and nature of work
• Client name and contact details
• Principal designer and principal contractor details
• Expected project duration
• Key project phases and milestones

2. Management of the Work

• The management structure and responsibilities
• Health and safety goals for the project
• Arrangements for cooperation between contractors
• Site induction arrangements
• Welfare facilities
• Consultation with workers

3. Arrangements for Controlling Significant Risks

This is the core of the plan. It must address arrangements for managing risks including:

• Site security and public protection — hoarding, signage, pedestrian routes
• Delivery and removal of materials — vehicle routes, loading zones, lifting plans
• Services and utilities — identification and protection of buried/overhead services
• Temporary works — design, installation, and removal of temporary structures
• Hazardous materials — asbestos, lead, COSHH substances
• [Working at height](/blog/working-at-height-regulations) — hierarchy of control, edge protection, scaffolding
• Excavations — ground conditions, shoring, service avoidance
• Demolition and dismantling — structural integrity, exclusion zones
• Noise and vibration — limits, controls, monitoring
• Fire prevention — hot works permits, fire points, evacuation routes

4. The Health and Safety File

Arrangements for the health and safety file, including:

• What information will be collected during construction
• How it will be gathered and organised
• When it will be handed over to the client

5. Site Rules

Practical rules including:

• PPE requirements by zone
• Smoking, alcohol, and drug policy
• Permit to work requirements
• Speed limits and vehicle rules
• Emergency procedures
• Toolbox talk requirements

Construction Phase Plan vs RAMS

A common question: if you have a construction phase plan, do you still need RAMS?

Yes. They serve different purposes:

Document: Construction phase plan — Scope: Whole site/project — Who Prepares: Principal contractor — When: Before construction starts

Document: RAMS — Scope: Specific task/activity — Who Prepares: Individual contractor — When: Before each task starts

The construction phase plan sets out the site-wide arrangements. Individual RAMS documents provide the task-specific risk assessments and method statements.

For example, the construction phase plan might state: "All working at height requires edge protection. Scaffolding must be erected by a competent contractor." The RAMS for "scaffolding erection" would then detail the specific hazards, control measures, and step-by-step method for that particular scaffold on that particular site.

How They Link Together

In a well-managed project:

1. The construction phase plan references the types of RAMS required
2. Each contractor produces task-specific RAMS that comply with the plan's requirements
3. The principal contractor reviews and accepts RAMS before work begins
4. The construction phase plan is updated as new risks emerge or conditions change

Common Mistakes

Writing it after work has started. The plan must be prepared before the construction phase begins. A retrospective plan defeats its entire purpose and is a CDM breach.

Copying a generic template. Every project is different. A construction phase plan must be site-specific and address the actual risks of your project. A generic plan for a "typical construction site" won't cover the 11kV cable running through your particular site.

Making it too long. The HSE is clear: the plan should be "proportionate." A 100-page plan for a bathroom refit is not proportionate — it's a sign nobody has thought about what actually matters.

Not updating it. The plan is a living document. When designs change, new contractors arrive, or unexpected conditions are found, the plan must be updated.

Not sharing it. Every contractor on site should have access to the relevant parts of the construction phase plan. If they don't know the site rules and emergency procedures, the plan isn't working.

Confusing it with the health and safety file. The construction phase plan covers the construction period. The health and safety file is the information handed to the client at the end of the project for future maintenance and alterations. They're different documents with different purposes.

Construction Phase Plan Template: Key Sections

While every plan should be project-specific, here's a structure that covers the CDM Schedule 1 requirements:

1. Project overview — name, address, client, duty holders, duration
2. Project description — scope of work, key phases, existing conditions
3. Management structure — organogram, responsibilities, competence requirements
4. Communication arrangements — site meetings, notice boards, toolbox talks
5. Site rules — PPE, permits, working hours, welfare, emergency contacts
6. Risk management — significant risks identified, control strategies, RAMS requirements
7. Specific risk arrangements — working at height, excavation, demolition, services, asbestos, fire
8. Welfare and first aid — facilities, first aiders, nearest A&E
9. Training and induction — site induction content, CSCS/competence requirements
10. Emergency procedures — fire, medical, structural collapse, environmental incident
11. Monitoring and review — inspections, audits, plan review triggers
12. Health and safety file — collection arrangements, format, handover

How AI Can Help with CDM Documentation

Preparing CDM-compliant documentation traditionally involves days of writing. The construction phase plan alone can take 4-8 hours for a medium project, plus individual RAMS for each activity.

AI RAMS software can dramatically reduce this burden. By describing your project scope, the AI can:

• Identify all the distinct activities requiring separate RAMS
• Generate task-specific risk assessments with relevant legislation citations
• Produce method statements with practical, activity-specific control measures
• Ensure consistent terminology and cross-references across all project documents

This doesn't replace the principal contractor's responsibility to prepare the construction phase plan — that requires professional judgement about site-specific arrangements. But it can produce draft RAMS that are ready for review rather than starting from a blank page.

For a medium-sized project like a house extension, AI can generate 5-8 task-specific RAMS in the time it used to take to write one manually. That's the difference between documentation that exists in theory and documentation that's actually complete before work starts.

Key Takeaways

• Every construction project under CDM 2015 needs a construction phase plan — not just notifiable projects
• The principal contractor (or sole contractor) must prepare it before construction begins
• It must be proportionate to the project — detailed enough to manage risks, not so long nobody reads it
• It's the site-wide management plan; individual RAMS sit underneath it for task-specific safe systems of work
• CDM Schedule 1 sets out the required contents — follow it as your checklist
• The plan is a living document that must be reviewed and updated throughout the project
• AI tools can generate the task-specific RAMS that support the construction phase plan, saving significant time on CDM documentation