CDM 2015 Regulations: A Guide for London Homeowners

CDM 2015 places legal duties on every party involved in a construction project: the client (the homeowner), the Principal Designer, the Principal Contractor, designers, and contractors. The regulations are enforced by the Health and Safety Executive (HSE).

The purpose of CDM 2015 is to ensure that health and safety is considered and managed at every stage of a project — not only during construction but in the design and planning stages, and in the future maintenance and use of the building.

For domestic clients (homeowners), the regulations recognise that most homeowners are not construction professionals and may not be aware of their duties. CDM 2015 therefore provides that where a domestic client does not fulfil the client duties (e.g. appoints no Principal Designer), those duties transfer to the Principal Contractor by default.

• **Why it matters in practice:**
• A contractor who does not understand or follow CDM 2015 duties:
• •May not appoint a Principal Designer for a notifiable project
• •May not produce a Construction Phase Plan
• •May not maintain a Health and Safety File
• •May not manage subcontractors' health and safety obligations

This creates risk for the homeowner as well as the contractor. A properly run CDM-compliant project has a Construction Phase Plan, a named Principal Contractor, and (for notifiable projects) a named Principal Designer and HSE notification.

• **Client (the homeowner):**
• As a domestic client, you have legal duties under CDM 2015 — but these are limited in practice. Your main duties are:
• •To make suitable arrangements for managing the project, including welfare facilities
• •To allow sufficient time and resources for each stage
• •To provide pre-construction information (information you have about the property that is relevant to health and safety — e.g. asbestos surveys, structural surveys, drainage plans)
• •To ensure that a Principal Designer is appointed for notifiable projects

In practice, for most domestic projects, your contractor will manage CDM compliance on your behalf. You should, however, expect your contractor to discuss CDM requirements with you, particularly on larger or notifiable projects.

• **Principal Designer:**
• The Principal Designer is the designer in overall control of the pre-construction phase — typically the architect, but may be a specialist CDM consultant. The Principal Designer's role is to:
• •Plan, manage, monitor and coordinate health and safety in the pre-construction phase
• •Identify, eliminate or control foreseeable risks
• •Ensure cooperation between designers
• •Prepare the pre-construction information pack
• •Produce the Health and Safety File at project end

For smaller domestic projects (non-notifiable), the Principal Designer role is sometimes absorbed into the Principal Contractor's responsibilities.

• **Principal Contractor:**
• The Principal Contractor is the contractor in overall control of the construction phase. On a design-and-build project with a single main contractor (such as rcbGroup), the Principal Contractor role is fulfilled by that contractor. The Principal Contractor's role is to:
• •Plan, manage, monitor and coordinate the construction phase
• •Produce the Construction Phase Plan before work begins
• •Manage the safe interface between trades and subcontractors
• •Ensure welfare facilities are provided
• •Cooperate with the Principal Designer on matters affecting both phases
• •Produce the Health and Safety File at project end (where no Principal Designer is appointed)

**Designers:** All designers (architects, structural engineers, specialist designers) have a duty to consider health and safety in their designs and to communicate design risks to the Principal Designer and Principal Contractor.

**Contractors:** Subcontractors have duties to cooperate with the Principal Contractor, follow the Construction Phase Plan, and not carry out work that is likely to endanger any person.

• Not all construction projects are notifiable to the HSE. Notification is required only where the project is expected to:
• •Last more than 30 working days with more than 20 workers simultaneously employed at any point, OR
• •Exceed 500 person-days of construction work

**In practice for London domestic projects:** Most domestic extensions and loft conversions are not notifiable — they typically involve fewer workers and person-days than the thresholds. A full house refurbishment with multiple trades working simultaneously over an extended period may cross the threshold.

Where notification is required, the client (or the Principal Contractor on behalf of the domestic client) must notify the HSE using the HSE's online F10 notification form before the construction phase begins.

• **Even where the project is not notifiable, CDM 2015 still applies:**
• The threshold for notification is separate from the threshold for CDM compliance. CDM 2015 applies to all construction projects. Non-notifiable projects still require:
• •A Principal Designer (or the duties to transfer to the Principal Contractor)
• •A Construction Phase Plan
• •A Health and Safety File

The Construction Phase Plan for a small domestic project can be brief — a document that sets out the site rules, traffic management, welfare arrangements, emergency procedures, and the principal risks on the project. It does not need to be a lengthy document for a small renovation.

One of the client's specific duties under CDM 2015 is to provide the Principal Designer and Principal Contractor with relevant pre-construction information about the property. For a domestic renovation in London, this typically includes:

**Information the homeowner should try to obtain before the project:**

• •**Asbestos survey:** A domestic survey (formerly called a Type 1 Survey) that identifies whether asbestos-containing materials are likely to be present. Essential for any pre-2000 property where intrusive work is planned. An asbestos survey costs £150–£350 for a standard Victorian terrace. If asbestos is found, a management plan and (for removal) a licensed contractor are required.

• •**Previous structural surveys or structural engineer reports:** Any prior reports about the property's structure, movement, or defects. These inform the design and safe working approach.

• •**Drainage plans:** The position of underground drainage, manholes, and public sewers. Relevant where extensions or groundworks may affect drainage routes. The sewerage undertaker (Thames Water in most of London) can provide records.

• •**Party wall information:** Any Party Wall Awards or agreements from previous works. Relevant to the Principal Designer's assessment of shared structure risks.

• •**Contamination or ground condition information:** Where the property is on former industrial land, fill material, or near known contamination, a ground investigation report is relevant.

**The practical implication:** Providing good pre-construction information allows the contractor to produce a better Construction Phase Plan, price the project more accurately, and avoid unexpected discoveries that cause delay and cost. A contractor who does not ask for pre-construction information, or who starts work without it, is not running a CDM-compliant project.