The JCT suite of contracts is one of the most widely used frameworks in UK construction. A major strength lies in the way it defines responsibilities, making clear who does what. Here’s a breakdown of the main JCT roles you’ll come across.
Core Roles
Employer
The party commissioning the works. They appoint the contractor, provide information, make timely payments, and ensure funding is in place.
Contractor
Responsible for delivering the works in line with the contract. They manage labour, plant, and subcontractors, maintain health and safety, and notify the CA of claims for extensions of time or loss and expense.
Architect / Contract Administrator (CA)
Acts both as the Employer’s agent and as an independent certifier. They issue instructions and variations, certify payments, assess extensions of time, and decide on loss and expense.
Quantity Surveyor (QS)
Manages project finances: preparing interim valuations, pricing variations, monitoring costs, and producing the final account.
Additional Roles
Clerk of Works
Provides quality assurance on site, inspecting workmanship and compliance, and reporting back to the CA.
Subcontractors
Deliver specialist packages of work. JCT distinguishes between domestic subcontractors (appointed by the contractor) and named subcontractors (approved by the Employer).
Extended and Specialist Roles
Employer’s Agent
Common under Design & Build contracts, taking on many CA duties but without design responsibility.
Principal Designer & Principal Contractor (CDM 2015)
Statutory health and safety roles. The Principal Designer manages risk during design; the Principal Contractor oversees health and safety during construction.
Project Manager
Not always referenced in JCT, but often appointed by Employers to oversee delivery across time, cost, and quality.
Specialist Consultants
Structural engineers, M&E designers, and other consultants provide essential design input and technical advice, usually appointed directly by the Employer.
Why Clear Roles Matter
Clarity avoids duplication, reduces disputes, and ensures projects run efficiently. JCT’s structure means everyone knows their responsibilities, but the challenge is making sure they carry them out consistently.
How Metroun Consultants Can Help
At Metroun Consultants, we help Employers, Contractors, and project teams understand and manage their roles under JCT contracts. From advising on contract administration to supporting claims, payments, and compliance, our guidance keeps projects moving and disputes to a minimum.










