Stage 2 of 7 · Design
BIM coordination and clash detection
Combine discipline models, find clashes and resolve them before they reach site.
- ProfessionalIDS 1.0 and BCF 3.0: check model data, raise and close issues +1 more
- Free videos2 videos
- Output
- Federated model, clash report and BCF issues
- Module
- BIM, CAD and coordination
- Documents
- Standards and references
What it is
BIM coordination brings the architectural, structural and services models together into a federated model and checks that they fit. Clash detection finds hard clashes, where elements occupy the same space, and clearance clashes, where space for access, maintenance or insulation is missing. The aim is to fix problems in the model before they become rework on site.
Coordination runs as a regular cycle: models are uploaded and checked, clashes are grouped and assigned, and the design team resolves them by the next round. Issues are exchanged in BCF so each discipline sees the viewpoint in its own tool. Rules agreed at the start, such as tolerances and which discipline moves for which, keep meetings short.
Who does it
- BIM coordinator
- Federates models, runs clash tests and chairs coordination meetings.
- Discipline modellers
- Resolve assigned issues in their authoring models.
- Information manager
- Sets the information requirements and the exchange schedule.
- Contractor's site team
- Checks buildability and installation sequences against the model.
How it runs
Agree requirements
Set model requirements, levels of information need, origins and clash rules in the BIM execution plan.
Receive and check models
Import discipline models and check origin, naming and required properties.
Run clash tests
Run tests by discipline pair with agreed tolerances and clearance rules.
Triage and group
Remove duplicates, group clashes by cause and assign each group to a responsible discipline.
Exchange issues
Issue BCF topics with viewpoints and track responses.
Verify and repeat
Re-run tests on updated models, close resolved issues and report the remaining ones.
How it differs by country
- United Kingdom
- BS EN ISO 19650 and the UK BIM Framework set information management on projects, with exchange information requirements and a BIM execution plan. Central government projects are expected to follow this approach.
- Germany
- DIN EN ISO 19650 is adopted, and federal infrastructure projects have used BIM requirements under the government's BIM masterplan. GAEB bills of quantities can be linked to model elements through DIN SPEC 91350 BIM-LV containers.
- France
- BIM requirements are usually set in the project's charte BIM and convention BIM. Open exchange through IFC is commonly required.
- United States
- The National BIM Standard-United States and owner-specific BIM requirements are common. COBie is used to pass asset data from models to facility owners.
- International
- ISO 19650 defines information management across the asset life cycle, and buildingSMART maintains open standards such as IFC, BCF and IDS.
Common mistakes
- Models with different origins or units, producing false clashes.
- Testing every discipline against every other at once, giving thousands of meaningless clashes.
- No agreed tolerance or priority rules, so meetings argue about who moves.
- Tracking issues in screenshots and emails instead of BCF.
- Not re-running tests to confirm fixes.
- Ignoring clearance for access, maintenance and insulation.
In OpenConstructionERP
Module: BIM, CAD and coordination
The BIM, CAD and coordination modules support this cycle. CAD Import converts DWG, DGN, RVT and IFC, and BIM Hub stores models and elements with model diffs. BIM Requirements handles IDS and COBie requirement formats. Clash Detection runs interference and clearance checks with a discipline matrix and BCF export, Clash AI Triage assists triage, and Clash Cost Impact estimates rework cost per clash. BCF Issues & Viewpoints manages BCF topics, and Coordination Hub rolls up federations, clashes and BCF activity.
CAD Import · BIM Hub · BIM Requirements · Clash Detection · Clash AI Triage · Clash Cost Impact · BCF Issues & Viewpoints · Coordination Hub
The app runs at openconstructionacademy.com/app for course learners.
Free videos
Courses
Practise it in OpenConstructionERP
The free videos explain the process. The full course lets you run it yourself in the ERP, task by task.