Principal Contractor
Principal Contractor — One Team. One Contract. One Accountability.
RCB acts as Principal Contractor on residential and commercial projects across London. We control the construction phase, coordinate all trades, manage compliance, and deliver from start to handover.
One accountable team from start to handover.
The Principal Contractor controls the construction phase of a project. That means coordinating all trades, managing site safety, ensuring work flows correctly, and managing the flow of information between design and construction teams. It means one point of contact for the client and one accountable party for delivery.
When you appoint RCB as Principal Contractor, you are not managing five separate trades, chasing subcontractors, or trying to resolve disputes between specialists. You deal with us. We deal with everything else.
This model works for straightforward house extensions and complex multi-phase refurbishments alike. What changes is the scale of coordination — the principle does not.
What's included
How It Works
The RCB process for this service.
Pre-Construction Review
We review the design, specification and planning position. We identify any gaps in information, compliance requirements and the correct appointment structure.
Scope & Programme
We prepare a detailed written scope of works and a construction programme. These documents define what is being built, in what order, and to what specification.
Procurement
We appoint and manage all trades required to deliver the project. Subcontractors are selected, contracted and managed by RCB — not by the client.
Managed Construction
RCB controls the site. Weekly updates, variation management, Building Control inspections and quality control are all managed by us throughout the construction phase.
Handover
We compile and issue full handover documentation — including the health and safety file where required — and manage snagging through to formal completion.
Planning & Regulations
Under the CDM Regulations 2015, a Principal Contractor must be formally appointed on any project that will involve more than one contractor. The Principal Contractor is responsible for planning, managing, monitoring and coordinating health and safety throughout the construction phase. RCB takes this responsibility seriously. We prepare the Construction Phase Plan, manage RAMS, coordinate Building Control and maintain a health and safety file where required. For projects requiring a Principal Designer appointment, RCB coordinates the correct professional route.
FAQs
Common questions.
What is the difference between a builder and a principal contractor?
A builder typically carries out specific trade work — groundworks, brickwork, carpentry and so on. A principal contractor manages the entire construction phase — appointing and coordinating all trades, managing site safety, controlling the programme and acting as the single accountable party to the client. RCB acts as principal contractor, not just as a trade.
Do I need a principal contractor for a house extension?
Under CDM Regulations 2015, a principal contractor must be appointed on any project involving more than one contractor. In practice, this means the vast majority of house extension projects. The appointment does not need to be complex or expensive — it simply needs to be done correctly. RCB handles this as a matter of course.
What is a construction phase plan?
The Construction Phase Plan is a document prepared before construction starts that sets out how health and safety will be managed on site throughout the construction phase. It covers site rules, emergency procedures, welfare arrangements, risk management and how information will be communicated. Under CDM Regulations, the principal contractor is responsible for preparing and maintaining this document.
Who coordinates Building Control on a principal contractor project?
The principal contractor coordinates Building Control notifications, inspections and approvals on behalf of the client. RCB manages this from the initial commencement notice through to the completion certificate — including coordinating stage inspections and providing evidence of compliance.
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