Why Design Verification Should Start Before Clash Detection

The current spectrum of the U.S. AEC industry is much more complex and poised than ever before. Perhaps the costliest issue is coordination challenges between verticals.

Evidently, when MEP, structural, and architectural systems are designed in silos, the consequences are overlaps, coordination issues, and clearance breaches. More importantly, they remain unidentified until clash detection takes place.

Nevertheless, waiting until clash detection is pursued to spot problems is a basic workflow gap. Well, it costs construction projects considerable time and money.

So, if design verification happens before clash detection, it helps establish a baseline of precision, making clash detection more efficient and eliminating expensive design rework later.

The reality for current AEC professionals is that teams that prioritize early design verification strongly outperform those that consider clash detection as the main quality control initiative. Design verification entails extensive validation tasks involving code compliance checks, system performance authentication, and confirmation of design intent. Note that these verification activities should precede clash detection. The benefits? To ensure models have error-free, conformant, and coordinated data ahead of being compiled for geometric conflict evaluation.

Design Verification in AEC Operations

Design verification is a vital systematic procedure that confirms that MEP, architectural, civil, and structural designs align with project requirements, design standards, and building codes prior to final coordination. We know that the main focus of clash detection is exclusively on geometric conflicts among physical components. On the contrary, design verification emphasizes the examination of the core accuracy of individual discipline models.

It is important to understand that AEC professionals differentiate between verification and validation. While verification tests whether designs are made correctly as per specifications, validation examines whether the design itself matches project needs. In reality, design verification involves verifying MEP equipment clearances against architectural plans and authenticating structural framing loads. It further necessitates checking that electrical and plumbing systems conform to guidelines like IPC/UPC and the NEC.

Therefore, if AEC firms avoid early verification, they accumulate errors throughout several discipline models before clash detection starts. Keep in mind that these unverified models comprise code breaches, specification gaps, and coordination assumptions. Essentially, clash detection tools simply cannot address these. They can identify geometric conflicts.

Importance of Clash Detection in Design Coordination

Undoubtedly, clash detection is now an industry-standard approach. It is an AEC firm’s go-to tool to spot coordination issues among building systems. Leveraging dedicated BIM software like Navisworks, AEC teams merge discipline-specific models into a unified model and perform automated tests to spot hard, soft, and workflow clashes.

Bear in mind that clash detection signifies only one element of a robust coordination strategy. It operates within defined parameters—when teams create clash detection norms and tolerances, the tool looks for conflicts that match those parameters. If individual discipline models have unconfirmed data, flawed specifications, or unvalidated design assumptions, clash detection operates on compromised information.

Apparently, when clash detection is executed, it flags the physical interference, while the underlying design mistakes remain unresolved. Then, the team has to spend significant time resolving a clash that shouldn’t have been there if early verification had spotted the specification issues beforehand.

Value of Design Verification Preceding Clash Detection

The true value of design verification lies in the establishment of model precision before clash detection. This sequencing is of great importance. By substantiating individual discipline designs first, AEC teams can avoid specification mistakes, design assumptions, and code violations that would otherwise make clash resolution complicated. Early-stage verification activities play the role of quality gates, removing poor-quality information from entering the clash detection process.

The main reasons for favoring early design verification are as follows:

• Confirming Code Compliance Before Coordination

Architectural, structural, and MEP models must individually satisfy applicable building codes. This should be ensured before being integrated. If AEC teams wait until clash detection, some models may contain code breaches that were undetected during coordination reviews.

• Validating Equipment and Component Specifications

AEC firms must validate the size, clearance, and mounting specifications of every piece of equipment against manufacturer protocols. Again, this validation should be executed before merging the models. The result is that clash detection spends less time trying to address conflicts triggered by specification mistakes.

• Establishing and Communicating Design Intent

Verification procedures mandate that teams verify whether their models precisely represent the intended design direction. This helps prevent misinterpretation and design assumptions.

• Testing System Performance Assumptions

Early-stage verification guarantees that mechanical equipment selections, plumbing fixture counts, and electrical loads meet project requirements prior to detailed coordination.

• Establishing the Relevance of Coordination Rules and Tolerances

When individual models have already been authenticated for precision, clash detection norms and tolerances become valuable parameters. They assist in catching genuine conflicts instead of false positives stemming from unconfirmed data.

Repercussions of Skipping Early Design Verification

Bypassing the early design verification has severe financial and schedule implications. They are well documented in construction industry research. Studies indicate that 30% of all construction work requires rework, with 70% attributed to design-induced issues. Moreover, research also reveals that direct rework expenses average 5% of overall construction expenditures. This means that a $10 million project typically incurs around $500,000 in rework costs.

Thus, when AEC firms delay verification until clash detection takes place, they face the following downstream problems:

• Rework Increases During Clash Resolution

When clash detection flags conflicts, teams have to assess whether the conflict stems from actual coordination issues or from design mistakes. This assessment takes substantial time and prolongs coordination cycles.

• Clash Resolution Becomes Costlier

Addressing clashes late in design creation leads to ripple effects throughout all disciplines. Changes executed to address one clash seldom create new clashes. This extends the time of the coordination process indefinitely.

• Construction Phase Rework Multiplies Drastically

Undetected design errors from preconstruction phases inevitably emerge at the time of actual construction. On-site teams find that equipment is not a good fit, systems are not connected, or components are in violation of local code amendments. These revelations result in costly change orders and schedule delays.

• Team Collaboration Worsens

When all discipline teams take too much time in clash resolution without any resolution progress, trust worsens, and communication breaks down. So, design verification at the onset ensures the avoidance of this scenario.

• Project Schedules Compress Unusually

Reduced schedules pressure teams to overlook verification steps entirely. This creates a self-reinforcing cycle where later phases have to absorb quality control tasks that should have taken place earlier.

Sound Strategies for Incorporating Early Design Verification

Prioritizing the implementation of early verification necessitates that an AEC business set clear workflows to authenticate design precision before coordination commences. The firm should define verification roles matching design standards, code rules, and project specifications. Remember that verification initiatives must happen during every discipline’s model creation.

Practical verification efforts consist of confirming model precision against structural and architectural base models, authenticating MEP equipment choices’ alignment with space constraints, verifying code adherence for MEP systems, and validating fixture and equipment schedules in line with design specifications. Teams also need to establish collaboration tools, such as BIM 360, and utilize coordination tools proactively during model creation and not responsively after models are completed.

Clearly, when design verification happens before clash detection, the consecutive clash identification cycles become more focused and shorter. Then, teams can set valuable clash detection tolerances, as underlying models comprise error-free data. On-site teams also get coordination drawings that mirror genuine coordination choices instead of unaddressed conflicts brought to construction.

Conclusion

From the analysis above, it emerges that design verification and clash detection constitute sequential workflow elements within robust AEC coordination procedures. Design verification ensures the accuracy of the model and code compliance before clash detection kicks off. Implementing early design verification prior to clash detection allows AEC firms to attain quantifiably better project outcomes in comparison with firms that favor clash detection as the main QC approach.

Uppteam’s holistic BIM modeling solutions and 3rd-party QC offerings particularly address this coordination need. Our experienced team pursues in-depth design verification throughout all disciplines using tools like Navisworks, Revit, and BIM 360.

Reach out to Upstream now to explore how remote design verification and QC services can transform your coordination workflows.