BIM Clash Detection for Error-Free Construction Projects

Hard clashes

Hard clashes occur when two or more components occupy the same space in the 3D model. A conflict would be a nightmare to fix during or after construction. For example, an air conditioning duct running through a steel beam means one of them has to move.

Soft clashes

Soft clashes occur when objects do not have enough clearance for access and maintenance. Say for example an electrical panel is installed too close to a wall. This makes it tough for technicians to get in there for repairs. It is a soft clash.

Workflow conflicts

Workflow clashes occur when the construction sequencing is wrong. For example, scheduling plumbing before the concrete pour or installing ductwork before the structural frame is up creates major sequencing problems.

Regulatory clashes

Regulatory clashes occur when we see violations of industry codes and safety protocols. If we do not catch them, they can lead to legal and safety headaches. For instance if fire sprinkler equipment is installed too far apart, it is a clear violation of fire safety rules.

Operational interferences

Operational interferences occur when a design limits maintenance or future use. An HVAC control panel above a false ceiling is a pain for engineers, who have to keep removing tiles just to get access.

Purpose of clash coordination meetings

Holding clash coordination meetings early in the design stage are crucial as they let architects, engineers and contractors flag and resolve interferences before anyone steps on site. These meetings ensure that all building systems are aligned and free of clashes between architecture, structure and MEP trades.

Also, getting collaborative feedback on a platform like BIM 360 cuts down on RFIs and change orders. It also reduces onsite changes, which helps the project stay on schedule and improves overall constructability.

Use of tools like Revit and Navisworks to create and audit 3D models

Architects, designers, engineers and other construction team members use popular BIM tools like Revit and Navisworks to build and check 3D models. They then combine the individual 3D models from each discipline into a single, data rich model. That combined model has to be clash checked before we can use it in later project stages.

Once a detailed clash report is generated, 3D modeling teams can make the needed changes in Revit. Then they check it again for any new conflicts. Applying extra layers of QA/QC helps validate the 3D model for accuracy and data integrity.

Adopting a Common Data Environment (CDE) for seamless coordination

A Common Data Environment, or CDE, is a crucial tool. It helps multiple stakeholders save, access and share project models, drawings, documents, images and other files on one central platform. This helps everyone use the most up to date information, which reduces risk down the line.

Real time access and version control leads to faster clash coordination, greater clarity and integrated project workflows. All of these, ensure that projects are streamlined, resulting in an error-free construction process.

Eliminating rework and reducing costs

By coordinating 3D models from multiple trades, preemptive clash detection gets rid of rework early in the design stage. Detailed clash visualization and removal helps manufacturing teams and job site crews with seamless fabrication and installation. Eliminating that rework speeds up construction, which saves both time and money.

Enhanced team communication

Teams can use visualization to improve communication. Getting stakeholders involved early also promotes efficient collaboration. And using a CDE or a cloud tool like BIM360 makes sure every team is working with the latest files.

Reducing construction risks

Risks on construction sites can be catastrophic putting people’s safety on the line. Removing clashes quickly gives us a clean 3D model that helps visualize hazardous areas, reducing construction risks. Immersive 3D representations also help stakeholders spot risks and resolve them faster.

Lower material waste

Ordering too much or too little material causes big cost swings from the budget. But stakeholders can use the coordinated, clash free 3D model to get precise quantity takeoffs with BOQs and BOMs linked to component pricing. We can even use several Revit or Navisworks extensions to calculate accurate costs for every single building element.

Faster approvals and handovers

Projects get faster Turnaround Times (TAT) with quicker approvals from local authorities and fast handovers to clients. When we send a clash free 3D model to the client for feedback, it improves their decision-making. Once it is approved, a QA/QC check is run on the model for data integrity before using it in other project phases.

Step 1: Aggregate trade-specific 3D models

Once each discipline creates its 3D model from the client’s input, combine them into a single federated model.

Step 2: Do automated clash detection

Use clash detection tools like Navisworks and set up rules for element comparison and tolerance levels.

Step 3: Classify and prioritize clashes

Run the program to find and categorize conflicts into hard, soft and workflow clashes.

Step 4: Extract markups and clash reports

The Navisworks tool generates a comprehensive report. It shows the clash location, elements involved, clash severity and the team assigned to fix it.

Step 5: Hold coordination meetings and resolve issues

Hold coordination meetings to prioritize issues, assign roles, and track resolutions and any pending problems.

Step 6: Review and validate the BIM model

Validate the BIM model with multi-layered QA/QC workflows. This includes checking component placement, verifying object properties, doing alignment checks and assigning parameters.