- Watch out
- What it costs
- Experienced readers
- Remember
- In BIMpedia
The general contractor (main contractor) is responsible for building the project: it plans the work, buys it in packages from subcontractors, runs the site, manages health and safety, and carries the risk of delivering on time and on price. For a coordinator, the contractor's needs are practical: what's approved, what's in each package, and what's coming next week.
| Role | What they do | What they need from information |
|---|---|---|
| Project manager | Runs the contract, programme and cost | Status, change, risk |
| Planner | Programme, sequence, logistics | 4D, zones, quantities |
| Commercial manager / QS | Package costs, valuations, change | Quantities by package |
| Design manager | Coordinates design and subcontractor design | Issues, approvals, model status |
| Package manager | Procures and manages subcontracts | Package scopes and interfaces |
| Site manager / superintendent | Runs the works daily | Approved information by area |
What contractors need from the model
- Package scopes: elements and quantities filterable by package, so each subcontract is clear.
- Zones and levels that match how the work is sequenced.
- Clear status: what's approved for construction and what's still changing.
- Interfaces between packages: where one trade ends and the next begins.
The fire-stopping around services is in neither the drylining package nor the MEP packages; each subcontractor assumes the other does it. At inspection, hundreds of penetrations are open, and the building control sign-off slips by a month.
The package manager uses the model to list every service penetration through fire-rated walls, assigns fire-stopping explicitly to one package, and attaches the list to the subcontract. Inspections pass the first time.
A school's packages are: groundworks, steel frame, roofing, curtain wall, MEP, drylining and ceilings. List three interfaces between packages where scope gaps often happen, and how the model can help.
Key takeaways
- The main contractor plans, procures, builds and coordinates the works, through a team of project managers, planners, QSs, engineers and site managers.
- Work is bought in packages (groundworks, frame, envelope, MEP, fit-out), each with its own subcontractor.
- Contractors use models for planning, logistics, quantities, package scopes, coordination of trades and site queries.
- They need information split by package, zone and level, with clear status: what's approved to build.
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Related tool
Play the programme on the IFC model: see it built day by day, find late work and sequence errors.
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