Bird Tools - Clash Preventor
Bird Tools Clash Preventor is a Revit add-in that detects clashes in real time while you model, running asynchronously in the background without freezing the interface, with Excel reporting and Navisworks clash report import.
Most clash detection workflows require a separate export-and-review cycle outside Revit. Bird Tools Clash Preventor brings that process into the authoring environment by testing modified elements for hard clashes as you work, flagging conflicts before they spread across sheets and schedules (Bird Tools, 2025).
Version 5.0 introduced asynchronous background processing, a feature the developer describes as exclusive to this add-in. All manual and real-time clash detection modes now run without freezing the Revit interface, so modeling can continue during detection. A live-updating clash preview list shows results as they appear, letting users fix issues while the scan is still running (Autodesk App Store, 2025).
Filtering options include category filters and parametric filters built on Revit Rule Filters (View Filters), with support for Revit links and IFC links. A link-to-link mode checks linked document instances against each other in a host file. Detected clashes display in a built-in Clash Browser with 3D section-box isolation and Excel export, and Navisworks XML clash reports can be imported for reconciliation inside Revit (Bird Tools, 2025).
Pricing is $20 USD per seat per year, with a discounted multi-seat plan at $299 per team (up to 20 users) per year. A 30-day free trial is available. The add-in supports Revit 2021 through 2026 on Windows.
Specifications
Pricing
Platforms
Used for
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Tasks
Pros and cons
Pros
- Real-time detection catches clashes during modeling, not after export.
- Background processing does not freeze the Revit interface (v5.0).
- Affordable pricing: $20 per seat per year with a 30-day free trial.
- Supports Revit links, IFC links, and link-to-link detection.
- Multi-seat discount at $299 per year for up to 20 users.
Cons
- Does not replace federated model review in Navisworks for large multi-trade projects.
- Parametric filtering relies on properly configured Revit Rule Filters in the project.
- Windows-only; no macOS or web version.
- Free trial is time-limited to 30 days with no feature restrictions noted.
Key features
Real-time clash prevention: Automatically tests modified elements for clashes as you model, catching conflicts before they propagate.
Asynchronous background processing: All detection modes run in the background without freezing the Revit interface (v5.0 exclusive).
Live-updating clash preview: Results appear in the clash list while detection is still running, so fixes can start immediately.
Link-to-link detection: Checks linked Revit instances against each other in a host document for inter-discipline coordination.
Category and parametric filtering: Filters elements by Revit category and parametric Rule Filters, supporting Revit links and IFC links.
3D section-box review: Frames clashing elements in a section box with an option to tile all open views for side-by-side review.
Clash Browser with Excel export: Built-in tabular clash report that exports to and imports from Excel.
Navisworks XML import: Brings Navisworks clash detection reports into Revit for visualization and resolution without leaving the authoring tool.
Multiple test configurations: Supports multiple category and parametric filter sets per project for flexible detection scoping.
Pricing
Free Trial
30-day trial
Free
30-day free trial for first-time downloaders. Full functionality included.
Single Seat (annual)
per year (12 mo)
$20.00
Per named user per year. Recurring and non-recurring options available. Verify on Bird Tools website (Bird Tools, 2026).
Multi-Seat Team (annual, up to 20 users)
per year (12 mo)
$299.00
Covers up to 20 named users per team. Recurring and non-recurring options available. Verify on Bird Tools website (Bird Tools, 2026).
Frequently asked questions
How much does Bird Tools Clash Preventor cost?
A single-seat license costs $20 USD per year. A multi-seat team license covering up to 20 users costs $299 USD per year. Both recurring and non-recurring subscription options are available.
Does Bird Tools Clash Preventor offer a free trial?
Yes. First-time downloaders get a 30-day free trial that starts when the download request is submitted. The trial includes full functionality.
Can I keep modeling while clash detection runs?
Yes. Starting with version 5.0, all detection modes run asynchronously in the background. The Revit interface stays responsive, and a live-updating clash list shows results while the scan is in progress.
Does Clash Preventor work with linked Revit models?
Yes. The tool supports Revit links and IFC links for category and parametric filtering. A link-to-link mode specifically checks linked document instances against each other in a host file.
Can I import Navisworks clash reports into Clash Preventor?
Yes. The tool includes a Navisworks Report Import mode that reads XML clash detection reports generated by Navisworks and displays them inside Revit for visualization and resolution.
Which Revit versions does Clash Preventor support?
The add-in supports Autodesk Revit 2021 through 2026 on Windows. Support for Revit 2026 was added in version 5.0, released in October 2025.
Is Bird Tools Clash Preventor a replacement for Navisworks?
It handles Revit-native clash detection and can import Navisworks reports, but it does not replace full federated model review or 4D simulation capabilities in Navisworks. It is best suited for catching clashes early during authoring.