Building Inspection: Drones Need Guidelines, Too
As a rule, building information modeling (BIM) is about so much more than designing in 3D. Its levels of information make a model useful for the entirety of a building’s lifetime, keeping track of many aspects of its design, construction, management and use.
However, any type of modeling can have difficulty with unpredictable factors like weather. BIM models have built-in limits so owners have to wait to see how real-world conditions affect the building.
So far, the approach has been to conduct regularly scheduled inspections of the façade. These inspections are often accomplished by outsourced specialists, each of which has its own notation method. This variability gets very confusing very quickly for a building owner who is tracking inspection history over a long period of time.
Luckily, this may not be the case for long.
Playing by the Rules
Notation, syntax and symbols are at the forefront of a new set of standards for exterior building inspection. These standards, issued by ASTM International, are part of the E3036 Guide for Notating Façade Conditions in the Field.
This guide is specifically designed for documenting deficient conditions in already-constructed buildings. Using a standardized shorthand notation system, building conditions can be documented either on existing drawings or photos of existing façades.
This standard process will help optimize BIM records and structural maintenance documentation for existing buildings. It will be especially useful for those with load-bearing exteriors, which typically require more frequent inspection.
“This standard will be particularly useful to building owners who maintain a database on the conditions of their façade,” said Michael Petermann, a principal at Wiss, Janney, Elstner Associates and an ASTM member.
“As periodic inspections occur, they can perform side-by-side comparisons of databases and drawings to confirm if conditions have worsened,” Petermann continued. “With the standard, they won’t waste time translating between notation systems of different firms.”
Guidelines for Drones
We’ve already heard about the future potential for drones to assist in infrastructure maintenance and repair and other BIM-related purposes. As this method becomes more feasible, it’s increasingly important to establish a set of rules for these robotic helpers—and that’s the next move for ASTM.
The standard for drones, which is still in development, is the WK52572 Guide for Visual Inspection of Building Façades Using Drones.
The guide will tackle the logistics for camera-equipped drones used to scan and document exterior conditions using video and still photography. It will likely encompass general guidance for safety, a protocol for video-scanning exteriors and storage of scan results for future use, among other things.
“This proposed standard will improve the quality of inspections by allowing drones with high-quality cameras to provide close-up views of parts of façades that can’t otherwise be seen,” said Petermann. Such inspection might include the tops of windowsills and other difficult-to-reach areas.