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By Bryan A. Merritt
Projects to renovate, expand, or alter existing buildings present challenges for both owners and the design/construction team. As-built drawings often are missing or do not reflect subsequent changes, and hidden or concealed conditions are often unknowns. In addition, RFPs rarely provide accurate information or articulate level-of-accuracy requirements. One team’s bid may be based on tape-measure orthogonal-based dimensioning, another on accuracy to 1/8-inch, a third on advanced geospatial technology. Often, levels of accuracy are difficult to achieve, or an owner’s expectations, when not defined, differ from the design team’s proposal.
Both the American Institute of Architects (AIA) and the Associated General Contractors (AGC) have created level of development (LOD) specifications that are gaining acceptance within the architecture, engineering, construction, owner/operator (AECO) industry. These essentially determine how definitively or accurately a detail can be measured, in terms of costing. LOD defines intent. What was missing was a commonly recognized standard within the industry for building documentation standards. The U.S. Institute of Building Documentation (USIBD) has developed a level of accuracy (LOA) specifications to fill this gap.
Design teams have long grappled with finding a way to eliminate error and develop specifications and documentation that achieve a consistent and specific level of accuracy. The USIBD LOA specifications guideline enables design teams and owners to specify and document existing conditions with a high level of accuracy. In particular, the successful matching of intent and means with methods was needed.
Clients often have a hard time defining or specifying their LOD or LOA requirements in RFPs, which rarely go beyond intent to describe expectations. When project disputes have arisen, they often centered on clients’ unmet expectations, which invariably could be traced back to poorly defined or nonexistent LOA or LOD specs. These new specifications give owners the accuracy and means to represent and document existing conditions. This is particularly important in existing-building renovation and improvement projects.
The new LOA specs focus on two primary goals: managing client expectations and functioning as a risk-mitigation tool. An example of the former is a retail project. The retail company had been using a consulting engineering firm for both scanning and MEP design for years. The client decided to “go out” to another scanning provider and do the design in-house. The client did not provide specs and went sole source with the aim of saving money. The new scanning firm indicated it could provide the registered point cloud in two weeks. It actually took two weeks to scan and then another four weeks to register the points. The new scanning provider did not use any controls or quality checks, or follow any type of specifications. The “final” point cloud showed that the store was 3 feet shorter than the construction documents indicated. Though this could be true and confirmed by a simple use of a tape measure, it appeared that the point cloud was inaccurate. The original engineering firm was brought back in to redo the project completely.
Starting with an LOA puts the emphasis on the final deliverable by placing a specification on the initial accuracy. Having a known starting place helps define the amount of time it’s going to take to complete the task. By not doing this in this project, the original provider got its tail caught in the door and could never catch up to its promises.
As a risk-measurement tool, LOA evaluates project risk. Without specs, risk increases. Risk is measurable uncertainty: You mostly know what you are getting into. But uncertainty results in immeasurable risk: You don’t know what you don’t know.
On another project, the proposal included the LOA for the project. This was a sensitive project that could become a court issue. The project was a new business built into a hillside, with a new keystone retaining wall. After a year, the client noticed that the vertical retaining wall had begun to bulge. While scanning the area with the bulge, the consulting engineering firm discovered additional “nonvertical” areas that were not initially part of the project. Because the firm followed a spec that was part of the LOA, it accomplished more than expected, found a problem no one had expected, and avoided issues later on.
The new LOA specifications are gaining acceptance within the industry, and many companies and organizations, including NASA, are incorporating them into their hardware/software programs. The new LOA specifications guide can be obtained by contacting USIBD at www.usibd.org.
Bryan A. Merritt, PSM/LS, is geospatial services core business leader, Erdman Anthony. He is vice president and secretary of USIBD.