More information, less time, reduced risk

The traditional process for acquiring an as-built reading of an elevator shaft requires engineers to go floor-by-floor with a measuring tape to survey the width of the shaft at each floor opening. These measurements capture the changes in the shaft width from floor-to-floor, providing subcontractors with the necessary information to assess how far off the wall they need to shim the rails to ensure they are perfectly straight for the elevator to run smoothly through the shaft.

Not only does the traditional surveying process take a long time, but it also puts workers at risk every time they have to access a floor opening. Even more, traditional surveying only captures a fraction of the elevator shaft information. For example, with traditional surveying we are only obtaining the measurements at the floor openings, not in between floors. That is, until now.

Hoffman Town Center
Alexandria, Virginia

Accurate as-built data is a critical component of any planning and design process – a fact that rings especially true in the realm of adaptive reuse projects. That’s precisely why Balfour Beatty utilized laser scanning instead of traditional surveying on the first phase of its work at Hoffman Town Center in Alexandria, Va. When the project team considered how to approach the renovation of a 348,000-square-foot, 1960s-era office building in the development, laser scanning was the obvious choice to obtain an exact digital reproduction of existing conditions.

Among multiple applications of laser scanning on the project, the team developed a way to laser scan elevator shafts and as a result, accomplished three things: 1) engineered significant safety risk out of the process; 2) reduced the time it takes to survey elevator shafts; and 3) captured 100% of the elevator shaft data.

To leverage the laser scanning technology, the project team crafted an outrigger arm to safely hold the scanner in the middle of the elevator shaft. By using the outrigger arm, the team was able to keep safety barriers in place on each floor. And, because it was no longer necessary to secure team members in safety harnesses while surveying elevator shafts, a major risk was eliminated in the process.

Using the outrigger arm design, the Balfour Beatty team was able to scan three to four floors at a time, significantly cutting down the time it takes to survey an elevator shaft. In this manner, the laser scanner is able to capture a complete reading of the entire elevator shaft, cataloging 100 percent of the dimensions for accurate, information-rich, as-built documents. Once measurements had been obtained, the team was able to create a field-accurate as-built document, enabling subcontractors to ensure the rails were accurately installed.

View more info on Laser Scanning.