Clash Detection
Concrete Bureau identifies and resolves conflicts between architectural, structural and MEP models before construction begins. We turn a pile of discipline models into a clear, tracked list of clashes — and drive each one to resolution.
What is clash detection?
Clash detection is the process of testing discipline models against each other to find physical interferences — a duct through a beam, a pipe through a wall — before they reach the site. Catching these in the model is a fraction of the cost of fixing them in concrete.
We audit the input models first, run detection across every discipline, and deliver an NWD model with viewpoints plus a structured report so nothing is lost between detection and resolution.
Who it is for
- General contractors and subcontractors coordinating trades
- Project teams that want fewer RFIs and less on-site rework
- Owners who need an independent check before construction
Types of clashes we catch
Not every clash looks the same, and each type needs a different fix:
- Hard clashes — two elements physically occupy the same space, such as a duct running through a beam
- Soft/clearance clashes — elements that technically fit but leave no room for insulation, access or maintenance
- Workflow clashes — sequencing conflicts, such as a wall scheduled before the ductwork that needs to pass through it
Setting the clash matrix and tolerances
Before running any test we agree a clash matrix with you — which discipline pairs get checked against each other (structure vs. MEP, architecture vs. structure, MEP vs. MEP) and what tolerance counts as a real clash for each pair. A structural connection might get zero tolerance, while a duct running near a beam gets a clearance allowance for insulation and access.
Getting the matrix right before the first run is what keeps a report a short, prioritised list instead of hundreds of false positives nobody has time to review — it's the main technical difference between a clash test that actually gets used and one that gets ignored after the first pass.
What you get
- Clash detection across all disciplines, with input models audited first
- An NWD model including viewpoints for every issue
- A structured report (Google Sheet format) tracking each clash
- Communication via chat and coordination meetings
- Direct communication with contractors and subcontractors
- CDE maintenance and administration
- Integration into your internal project meetings
Why catch clashes before the site does
A clash caught in the model costs a few minutes to flag and reassign. The same clash caught on site costs a stop-work order, a rework crew and a delay — often at a multiple of the price. That gap is the entire business case for running detection before construction starts.
Beyond avoiding rework, a tracked clash report gives every trade a single, shared list of what's outstanding, so nothing gets lost between the coordination meeting and the person actually fixing it in the model. Estimators and schedulers work from the same report to price and sequence the job — a set of drawings that clash on paper isn't a schedule anyone can actually commit to.
Our process
Model audit
We check every input model for readiness and a shared coordinate system.
Detection
Clash tests across all disciplines, grouped and prioritised by impact.
Reporting
An NWD model with viewpoints and a tracked report for every issue.
Resolution
Coordination meetings and contractor communication until clashes are closed.
FAQ
- How is clash detection different from coordination?
- Clash detection is the focused technical check that finds interferences; BIM coordination is the wider process of managing models, standards and resolution over a project. We offer both.
- How are reports delivered?
- As an NWD model with viewpoints plus a structured report (Google Sheets) so each clash is traceable from detection to closure.
- Can you coordinate directly with our contractors?
- Yes. We communicate with contractors and subcontractors and integrate into your internal project meetings.
- How often do you re-run detection during a project?
- As often as the models change — typically on a weekly or milestone-based cycle, so new clashes are caught while design changes are still cheap to make.
- Do you detect clearance and workflow clashes, or only hard clashes?
- All three. Hard clashes are the most obvious, but clearance and sequencing conflicts often cause just as much rework if they're missed.