Understanding the London Construction Industry: Trades, Roles & How Projects Are Organised
For homeowners and property investors undertaking construction projects for the first time, the structure of the UK construction industry — the different trades, professional roles, contractual arrangements, and delivery routes — can be confusing. Here is a practical explanation.
The Main Delivery Routes
Design-and-build: A single company (the design-and-build contractor) takes responsibility for both design development and construction. The client deals with one party from early design through to practical completion. This is what RCB Design & Build provides.
Traditional (design by architect, build by contractor): The client separately appoints an architect (who designs) and a main contractor (who builds). The architect acts as contract administrator. The client has two separate professional relationships and must coordinate between them.
Self-build / direct labour: The client manages trades directly, without a main contractor. Cheaper in principle (saves main contractor margin) but transfers all coordination, programme management, and risk to the client. Suits experienced self-builders; high risk for first-timers.
Principal Contractor vs Subcontractor
Principal Contractor (PC): Under CDM 2015 regulations, the PC has specific legal duties — managing the construction phase health and safety plan, coordinating subcontractors, controlling the site, and managing construction phase risk. For projects with more than one trade on site, a principal contractor must be appointed. RCB Design & Build acts as principal contractor.
Subcontractor: A trade company appointed by the main contractor to carry out a specific package — groundworks, structural steel, brickwork, plastering, electrics, plumbing, joinery, decoration. Subcontractors work to a main contractor's programme and are managed by the main contractor.
The Main Construction Trades
Groundworks: Foundation excavation, drainage, concrete slab. Often the first trade on site for an extension.
Brickwork / masonry: Structural blockwork, brickwork facing, cavity wall construction.
Structural steel: Erection of steel beams, lintels, and structural columns.
Carpentry: First-fix carpentry (roof structure, stud walls, floor joists) and second-fix (doors, skirtings, architraves, built-in furniture).
Plastering: Wet plaster or dry lining (plasterboard + skim) to walls and ceilings.
Plumbing: Pipework, drainage, hot water, heating systems.
Electrical: Wiring, consumer unit, sockets, lighting, data.
Tiling: Wall and floor tiles in kitchens, bathrooms, and other areas.
Flooring: Timber, engineered wood, LVT, carpet (though RCB does not supply or install carpet).
Painting and decorating: Internal and external decoration.
The Professional Team
Architect: Designs the project, produces planning and building regulations drawings.
Structural Engineer: Designs structural elements — beams, foundations, roof.
Party Wall Surveyor: Manages party wall notices and awards where applicable.
Planning Consultant: Advises on planning strategy and may manage the application process.
RCB Design & Build
RCB Design & Build provides an integrated design-and-build principal contractor service — managing architects, structural engineers, and all trade subcontractors from a single point of responsibility.