Accurate documentation of existing conditions is critical for successful structural engineering, especially when working on renovation projects. The U.S. Institute of Building Documentation (USIBD) has addressed this need with its recently updated Level of Accuracy (LOA) Specification v3.1, now available in its new Education Center. This document provides a comprehensive framework for specifying the required accuracy of building documentation projects, ensuring clarity and alignment among all stakeholders. For structural engineers, the LOA Specification is an indispensable tool for managing project expectations and achieving precise results.
The whole reason the LOA Specification was created was that there were no recognized standards for defining accuracy in building documentation. In my own practice, I often struggled to communicate and define accuracy on projects. I found that this issue was widespread—architects, engineers, and service providers alike faced challenges in determining what level of accuracy was appropriate. I recall one client confidently stating that they could achieve 1mm accuracy using a handheld laser range finder and therefore expected that accuracy level across the entire project. This reflected a fundamental misunderstanding of how accuracy is influenced by tools, methodology, and process.
Accuracy isn’t just a number—it’s an understanding of how error accumulates and how specifications should account for real-world conditions. The LOA Specification was born out of necessity, providing a shared language to prevent miscommunication and unrealistic expectations.
The Cost of Accuracy
One of the most common debates around accuracy specifications is cost. Higher accuracy requirements can drive up costs significantly, yet clients unfamiliar with the realities of data collection and processing often fail to recognize this. Educating stakeholders about the cost implications of higher accuracy is essential—but ironically, time spent on education itself adds cost to a project.
While it may seem logical to strive for the most accurate data possible, there is always a point of diminishing returns. I always start by asking, “What is the reason you think you need to achieve that level of accuracy?” This question gets to the heart of my philosophy: Intent defines process. Understanding the intended use of the data allows us to design an appropriate approach that meets project needs without unnecessary expense.
There’s a big difference between needing precise millimeter-level accuracy for prefabricated steel connections versus documenting a general space for planning purposes. Specifying accuracy beyond what is actually necessary can lead to overspending. The question then becomes: When is good enough, good enough?
Complementary to the BIM Forum’s LOD Specification
The LOA Specification works in harmony with the BIM Forum’s Level of Development (LOD) Specification, which focuses on the detail and completeness of building models. While LOD addresses the content and usability of BIM models, LOA establishes the accuracy of the underlying data used to create those models. Together, these specifications form a powerful combination for structural engineers who rely on precise, reliable information to make critical decisions.
Consider a renovation project involving seismic retrofitting. The LOD Specification can guide the modeling team in creating a detailed representation of the building’s structure, while the LOA Specification ensures that the underlying measurements are accurate enough to support the design. This integrated approach reduces uncertainty, streamlines collaboration, and minimizes risks.
Is the Industry Ready to Embrace a Standard?
The LOA Specification is now in its fourth publication, spanning over ten years. The USIBD has seen widespread adoption of the standard across the globe, but the question remains: Is the industry ready to fully embrace the USIBD’s LOA as a standard and incorporate it into project specifications and contracts?
Many firms use the LOA informally as a guideline, but until it becomes a standard contractual requirement, variations in expectations and misunderstandings will persist. Adoption of LOA in formal project documentation would reduce inefficiencies, provide clarity, and ensure that project teams are aligned on accuracy expectations from the outset.
The Implications of Implementation
By not addressing accuracy in project specifications and contracts, stakeholders leave themselves exposed to unmet expectations and potential project disputes. Defining intent early and crafting a specification that provides clear guidance on required accuracy—and nothing more—is crucial. When we all speak the same language, we are more likely to understand each other and minimize costly rework.
Training and Certification Opportunities
To help professionals fully understand and implement the LOA Specification, the USIBD now offers on-demand training and certification through its Education Center. These courses provide structural engineers and other industry professionals with the knowledge and skills needed to apply the LOA effectively in their projects. By earning certification, engineers can demonstrate their expertise in building documentation standards and enhance their professional credibility.
Recognizing Leadership in the Industry
The updated LOA Specification represents years of industry expertise and leadership. As chair of the LOA Subcommittee, I have been proud to work alongside our vice-chair Prof. Dr. Christian Hesse and dozens of other industry leaders to develop the LOA Specification helping to bring a much-needed tool to building documentation standards and fostering collaboration across the AEC industry.
Structural engineers face unique challenges when designing for renovation projects and working with existing conditions. The USIBD’s LOA Specification v3.1 provides a vital tool for addressing these challenges, offering a clear framework for specifying accuracy requirements and ensuring the reliability of building documentation. By complementing the BIM Forum’s LOD Specification and promoting effective collaboration, the LOA sets a new standard for precision and efficiency.
To learn more, download the LOA Specification for free and explore training opportunities at the USIBD’s Education Center at usibd.org/. ■
About the Author
John M. Russo, RA is the Founder, Past President and Board Member Emeritus of the U.S. Institute of Building Documentation. He is the President and CEO of Architectural Resource Consultants specializing in professional building documentation services in the U.S.