Concept design selects the route
Concept design tests viable systems, major plant, energy implications, utility requirements and spatial allowances. It should explain why a strategy is suitable before detailed information is produced.
Spatial coordination proves it can fit
Plant rooms, risers, ceiling zones and principal routes need to be coordinated with architecture, structure and specialist systems before technical design is fixed.
Technical design defines the information
Calculations, equipment criteria, drawings, schematics, schedules, specifications and interface details develop to the level required by the procurement and responsibility route.
Responsibility still needs to be explicit
A Stage 4 label does not define who completes contractor or specialist design. The appointment should assign each output, review and interface clearly.