RIBA Plan of Work

The RIBA Plan of Work is the UK construction industry's standard project lifecycle framework, setting out eight stages: Stage 0 Strategic Definition, Stage 1 Preparation and Briefing, Stage 2 Concept Design, Stage 3 Spatial Coordination, Stage 4 Technical Design, Stage 5 Manufacturing and Construction, Stage 6 Handover, and Stage 7 In Use. Each stage has defined core objectives, outputs and information exchanges, creating a consistent vocabulary used across architects, engineers, contractors, clients and project controls teams on UK projects.

For project controls work, the RIBA stages correspond to different levels of estimate and programme maturity. Stage 2 Concept Design typically corresponds to AACE Class 4-5 estimates with wide confidence ranges; Stage 4 Technical Design corresponds to Class 2-3; post-Stage 4 construction pricing is typically Class 1. QRA at Stage 2 is structured to account for high inherent uncertainty; QRA at Stage 4 and beyond is expected to be materially tighter. Understanding where a project sits in the RIBA stages determines what confidence levels are realistic to claim.

The RIBA Plan sits alongside the Government Soft Landings (GSL) framework and the CIC (Construction Industry Council) Scope of Services, with the three together providing the standard framework for building projects in the UK. Infrastructure projects often use sector-specific alternatives — HS2 Plan of Work, Network Rail GRIP, National Highways PCF — but the underlying logic of stage-gated lifecycle management is similar across all of them.