BIM clash detection is how professionals in architecture, engineering, and construction identify conflicts within their 3D building models.
It’s essentially a digital check, pinpointing instances where a pipe might run directly through a wall or a ventilation duct interferes with a structural beam. This process is key to preventing costly and time-consuming rework once construction begins.
The process works by analysing the different systems within a BIM model, such as the architectural layout, structural elements, and mechanical, electrical, and plumbing (MEP) components.
The software highlights where these elements improperly overlap; for example, if a large-diameter pipe intersects with a critical support column. Addressing these issues at the design phase leads to a more streamlined and accurate construction phase.
For AEC professionals, understanding and effectively using clash detection goes beyond just avoiding mistakes. It translates directly into better team collaboration, fewer delays, and projects that more closely match the original design intent.
Because of this, clash detection is an increasingly valuable skill to develop.
So today we are going to explore more about BIM clash detection and how you can use clash detection to improve your projects and advance your career.
Without further ado, let’s get to it!
Table of Contents
ToggleWhat is clash detection in BIM?
Clash detection in BIM is a systematic process for finding and resolving conflicts in a 3D building model.
It’s not just about identifying problems, but about actively making sure that all the different design elements fit together correctly. Think of it like a virtual dress rehearsal for your construction project.
By running clash detection, you can see if the different systems – like plumbing, electrical, and structure – interfere with each other before they become expensive problems on the job site.
This helps teams work together better and reduces the chance of errors during the actual build.
More on Interscale Education Blog: As-Built Documentation: Definition, Components, and Methods
What are the types of clashes in BIM?
Clashes in BIM aren’t all the same. They fall into a few different categories, each needing a slightly different approach to fix.
Here are the main types:
Hard Clash
A hard clash is the most obvious type of conflict.
It happens when two physical objects are trying to occupy the exact same space. For example, a pipe running directly through a steel beam or a duct colliding with a concrete wall are hard clashes. These are usually easy to spot and require a clear design change to fix.
Soft Clash
A soft clash is a bit more subtle.
It occurs when there isn’t a direct physical collision, but there is an overlap within a specified clearance zone. For example, a maintenance zone around a piece of equipment might overlap with a walkway. While not a direct physical clash, this can still create problems with maintenance or accessibility.
Workflow Clash
Workflow clashes are the least obvious, they usually involve scheduling or coordination issues between different systems or teams.
This could mean that one activity will block other activities that need to occur in the same space. For example, starting the electrical installation before the framing is completed can be a workflow clash that leads to delay and reworking.
How does clash detection work in BIM?
Clash detection in BIM uses specific software designed for analysing 3D building models.
These software are built to understand the geometry and relationships between different building elements, going beyond simple visual checks. They allow users to set up detailed rules for how different components should interact.
The process starts by establishing the criteria for what the software should consider a “clash.”
For example, you might define that any intersection between a structural element and a mechanical pipe is a clash. You might also specify that a certain clearance area around equipment needs to be free of any other elements.
These parameters dictate how the software will examine the model.
With the rules defined, the software automatically analyses the entire BIM model.
It systematically checks the location and geometry of every object against the defined clash rules, identifying conflicts between different systems. This automated process is much faster and more accurate than trying to find clashes manually.
The software then generates reports that clearly show where clashes are located.
These reports often include visuals and precise coordinates within the model, which helps the team quickly locate and understand each conflict.
Reviewing and resolving these clashes is an iterative process, and multiple rounds of clash detection and model adjustments are commonly needed to finalise a clash-free design.
Why is clash detection important in construction?
Clash detection is crucial in construction because it dramatically reduces risks and costs associated with building projects. Identifying and resolving conflicts early, during the design phase, is significantly more efficient and less expensive than dealing with them on the construction site.
Here’s why it’s so important in a construction project:
- Reduces Rework and Cost Overruns: Finding and fixing clashes in the digital model prevents expensive rework and change orders during construction. This helps keep the project within the allocated budget.
- Reduces Construction Delays: Conflict identification reduces construction delays brought on by unforeseen issues on the job site by proactively recognising conflicts prior to the start of construction. This maintains the project’s timeline.
- Improves Coordination: Clash detection promotes better communication and collaboration among the different project teams, including architects, engineers, and contractors. It ensures everyone is working from a unified and clash-free model.
- Betters Project Quality: By ensuring a better-coordinated design, clash detection leads to a higher quality end product with fewer on-site problems.
- Boosts Client Satisfaction: Delivering a project that is on time, within budget, and free from errors leads to increased client satisfaction and strengthens your professional reputation.
- Increases Project Profitability: Reducing rework, delays, and errors ultimately leads to more profitable projects due to increased efficiency and better resource management.
In short, clash detection is not just about avoiding errors, but it’s about building more efficiently. The goalis to deliver higher quality projects, and make sure project success.
What tools are used for clash detection in BIM?
Effective clash detection relies on specific software that can analyse complex 3D building models. These tools range from dedicated review platforms to integrated features within design software and cloud-based coordination systems.
So what are the tools used for clash detection in BIM? Here are some of the examples:
Navisworks
Navisworks is a dedicated BIM project review software that provides advanced clash detection capabilities. It’s designed to consolidate models from various BIM authoring platforms, creating a unified environment for clash analysis.
Key Features for Clash Detection:
- Aggregated Model Support: Combines models from different file formats (e.g., Revit, AutoCAD, etc.) into a single project for comprehensive clash analysis.
- Advanced Clash Rules: Allows the creation of detailed clash rules, including tolerances, clearance zones, and selection sets, to fine-tune the clash detection process.
- Clash Grouping and Management: Enables the grouping and classification of clashes by type, level, and severity, simplifying the review process.
- Clash Reporting and Visualisation: Generates interactive reports and visual representations of clashes for clear communication and issue tracking.
- Timeline-Based Clash Detection: Supports 4D simulations to identify clashes that occur over time, critical for construction sequencing.
Navisworks is particularly beneficial for large, complex projects with multiple stakeholders using different design tools, offering robust features for thorough clash analysis.
Revit
Revit is a BIM authoring software used extensively for design and documentation, which also offers built-in clash detection capabilities for model review and issue resolution.
Key Features for Clash Detection:
- Interference Check: Detects clashes between different elements within the Revit model based on specified categories and tolerances.
- Real-time Clash Visualisation: Visually highlights clashes directly within the 3D model environment as they are detected.
- Basic Clash Reporting: Generates simple reports of detected clashes, including locations and involved elements.
- Clash Resolution Tools: Provides basic tools for editing elements to resolve clashes directly within the Revit environment.
- Coordination Model Integration: Allows the linking of external models as coordination models for clash detection.
Revit is well-suited for teams who primarily work within the Revit environment, offering a direct and integrated approach to clash detection.
BIM 360 Coordinate
BIM 360 Coordinate is a cloud-based platform that facilitates model coordination and clash detection workflows across project teams. It emphasises collaboration and accessibility through its cloud-based environment.
Key Features for Clash Detection:
- Centralised Model Hosting: Stores and manages BIM models in a cloud environment, enabling all stakeholders to access the latest versions.
- Automated Clash Detection: Runs clash detection tests automatically at specified intervals, using preset rules and parameters.
- Clash Visualisation and Navigation: Provides a web-based interface for visualising and navigating detected clashes, promoting collaborative review.
- Issue Management: Allows team members to create, assign, and track clash-related issues, facilitating structured collaboration and problem resolution.
- Version Control: Enables comparison of model versions to understand changes that impact the project and allows pinpointing newly introduced clashes.
BIM 360 Coordinate is suited for larger projects with geographically diverse teams because it offers collaboration and clash detection capabilities via its cloud platform.
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Learn BIM Software for Clash Detection
Skills in software like Autodesk Revit, Navisworks, and BIM 360 are critical for effectively implementing BIM clash detection. These software solutions enable you to combine models, set up comprehensive clash tests, and resolve issues efficiently, moving beyond basic visual checks.
But where can you gain the practical skills?
Interscale Education offers online courses designed to equip AEC professionals with the hands-on software skills needed for BIM clash detection.
Here’s how Interscale Education can help you learn BIM software:
- Extensive Course Library: Access a wide range of over 100 certified courses in BIM software like Revit, Navisworks, and BIM 360.
- Practical, Real-World Lessons: Learn through video lessons that demonstrate how to practically use BIM software for real AEC projects and resolve clashes effectively.
- Expert Instructors: Benefit from experienced instructors with over 60 years of combined experience in both IT and construction.
- Flexible Learning Options: Watch over 60,000 minutes of on-demand video content whenever it suits you, and learn at your own pace.
- Industry-Recognised Certification: Earn certifications that are recognised within the industry, backed by our status as an Autodesk Gold Partner.
Interscale Education’s certified BIM software courses provide the skills you need to confidently integrate clash detection into your project workflows. These courses will help you manage project coordination, reduce conflicts, and ultimately, achieve more successful projects.
Build your technical skills with certified BIM online courses—sign up today.