Amogh N P
✦ In loving memory of Amogh N P — Architect · Designer · Visionary ✦
A computer screen showing a federated Building Information Model with structural beams, ducts and pipes of different colours overlaid, and a highlighted clash where a duct meets a beam, BIM clash detection, no people.
Unit IIBIM-Based Construction Management

BIM Technology & Clash Detection

The toolbox, openBIM, and finding clashes before site.

≈ 45 min + studio task

BIM runs on a family of tools and one of its most valuable powers. Learn the BIM software ecosystem — authoring, coordination and analysis tools — and the open standard IFC that moves a model between them without lock-in; and the signature capability of BIM-based management — automated clash detection, which finds the hard, soft and workflow clashes between disciplines on screen, days before they would be an expensive problem on site. Try the clash-type explorer.

Learning objectives

By the end of this lesson, you will be able to — mapped to the course outcomes for BIM-Based Construction Management:

1
CO2 · Understand

Review the BIM software ecosystem — authoring, coordination, analysis.

2
CO2 · Understand

Explain IFC and openBIM interoperability.

3
CO2 · Apply

Explain automated clash detection and its types.

4
CO2 · Analyse

Explain why finding clashes in the model saves cost on site.

Authoring, coordination, IFC

The BIM toolbox & openBIM

Disciplines model in different authoring tools, federate in coordination tools, and exchange via IFC (openBIM) without lock-in — the skill is coordinating models, not standardising on one app.[1, 3]

The BIM toolbox AUTHORINGarchitecture model structure model services model COORDINATIONfederate + clash-check ANALYSISenergy · cost · structure IFC Disciplines model in different tools and exchange via IFC — coordination matters more than one app. 'BIM means everyone uses one program' is a myth — the skill is coordinating and exchanging models.
DiagramThe BIM toolbox — authoring tools where disciplines model, coordination tools that federate and check, and analysis tools, exchanging via IFC

Authoring, coordination, analysis

BIM is delivered by a family of TOOLS. AUTHORING tools (Revit, ArchiCAD, Tekla) are where each discipline MODELS its part — architecture, structure, services. COORDINATION tools (Navisworks, Solibri, BIM 360) COMBINE those models into a federated whole and check them. ANALYSIS tools read the model for energy, structure, cost and more. No single tool does everything, and the disciplines model in different software — which is exactly why exchange between them matters. MISCONCEPTION→correct: 'BIM means everyone uses one program' — disciplines use different authoring tools; the skill is COORDINATING and EXCHANGING their models, not standardising on one app.[1]

openBIM — exchange without lock-in software A software B IFC open · vendor-neutral (buildingSMART) A model authored in one tool can be read, checked and coordinated in another through IFC. 'A BIM model is trapped in its software' is a myth — open standards keep the DATA portable. Data is the asset.
DiagramIFC is the open vendor-neutral standard that lets a model move between different software without lock-in
Find it on screen, not on site

Clash detection

Clash detection federates every discipline's model and finds conflicts automatically — hard (collision), soft (clearance) and workflow (timing) — turning a costly site stoppage into a quiet click-and-fix.[1]

Find it on screen, not on site structural beam AC duct CLASH! caught in the MODEL — days before site. a quiet click-and-fix, not a site stoppage. Combine every discipline's model and the software finds conflicts automatically. 'Coordination is checking drawings by eye' is a myth — automated detection catches what humans miss.
DiagramClash detection federates every discipline's model and finds where a beam passes through a duct, on screen before site

Find it on screen, not on site

The most celebrated power of BIM-based coordination is CLASH DETECTION. Combine (federate) every discipline's model and the software automatically finds where elements CONFLICT — a beam through a duct, a pipe with no room for its valve, two trades in the same place at the same time. Catching these in the MODEL, days before construction, turns a costly site stoppage, rework and dispute into a quiet click-and-fix. MISCONCEPTION→correct: 'coordination is checking drawings by eye' — humans miss clashes that automated detection across a federated 3D model catches in seconds; clash detection is one of BIM's clearest, measurable wins.[1]

Interactive

Explore clash types

Pick a clash type — hard, soft (clearance) or workflow — and read what it is and an example, and see why soft and workflow clashes cause real problems with no geometry overlapping.

Types of clash · pick one

Hard clash

What it is: Two objects physically occupy the SAME space — a direct geometric collision.

Example: A structural beam passing straight through an air-conditioning duct.

Soft and workflow clashes (clearance and timing) cause real site problems with no geometry overlapping.

Technology & clashes

At a glance

AspectDetailNote
AuthoringRevit, ArchiCAD, TeklaEach discipline models
CoordinationNavisworks, SolibriFederate + clash-check
IFC / openBIMOpen, vendor-neutral exchangeData outlives any vendor
Hard clashObjects collideBeam through duct
Soft / workflowClearance / timing conflictNo geometry overlap needed
Vocabulary

Key terms

Authoring tool

Where a discipline models its part (Revit, ArchiCAD, Tekla).

Coordination tool

Where models are federated and checked (Navisworks, Solibri).

IFC / openBIM

The open, vendor-neutral standard that moves a model between tools.

Federated model

Every discipline's model combined into one for checking.

Clash detection

Automatically finding conflicts between elements in the model.

Hard / soft / workflow clash

Geometric collision / clearance violation / time-sequence conflict.

Apply it

Studio task

For a typical ceiling void packed with a beam, a duct, a pipe and a cable tray, describe one hard clash, one soft (clearance) clash and one workflow clash that clash detection might find. Then explain in two sentences why catching these in the model is cheaper than catching them on site.

Check your understanding

Self-assessment

1. Automated clash detection is valuable mainly because it —

2. IFC (openBIM) exists to —

3. A 'soft' clash is —

In a nutshell

Recap

BIM runs on a toolbox — authoring (model), coordination (federate + check) and analysis tools.
Disciplines use different authoring software, so exchange matters; IFC (openBIM) moves models without lock-in.
Clash detection federates every discipline's model and finds conflicts on screen, before they cost money on site.
Clashes are hard (collision), soft (clearance violation) or workflow (time/sequence) — a good process catches all three.
Catching clashes in the model is one of BIM's clearest, measurable wins over checking drawings by eye.
The evidence

References & further reading

  1. [1]Sacks, Eastman, Lee & Teicholz, BIM Handbook — BIM tools, coordination and clash detection.
  2. [2]Autodesk Navisworks / Solibri documentation — federated models and clash detection types.
  3. [3]buildingSMART — Industry Foundation Classes (IFC) and openBIM.

Further reading

  • Sacks, Eastman, Lee & Teicholz — BIM Handbook.
  • Karen Kensek — Building Information Modeling.
  • buildingSMART — IFC / openBIM documentation.

Sources gathered and fact-checked June 2026. Published values vary by source, sample and method — treat as indicative and confirm against the cited standard before structural use.