Laser Scanning to Revit: As-Built Case Study

After 15 years in business, and over 13,000 As-Built surveys created, PPM finally took the plunge in February of this year and purchased our first laser scanner.  Starting with the “good old days” of tape measure, paper, and pencil, we have tested and implemented several different technological advancements in As-Built surveying over the years:  First it was the laser distance meter, which for about $500 literally changed the game for us (“You mean I don’t have to pull this tape 120 feet to get that measurement?”).  Then we started using the “COW” (Computer-On-Wheels) method where you skip the paper and instead bring your laptop with you on a rolling cart and create the As-Builts right there onsite.  After that, there were several iterations of more advanced surveying systems based on tablet computers with Bluetooth connectivity to the laser meter – enabling a skilled user to draw linework and insert objects directly from the measurements taken.  Each one of these and other innovations have enabled PPM to continue to provide the maximum value in the As-Built industry.  Laser Scanning will enable us to take our service to a whole level.

After 8 months of research and testing various laser scanners, we decided to go with the Zeb Revo mobile laser scanner from GeoSLAM.  The Zeb Revo takes 43,200 measurements per second, and generates a 3D point cloud that can be used in AutoCAD or REVIT to create traditional 2D As-Built drawings or 3D BIM models.  The device is extremely accurate (1/2” tolerance even in large spaces) and since it is mobile it is incredibly efficient – you hold it in front of you as you walk through the space capturing the 3D data.

One of the 1^st projects we scanned with our new toy was a 5,000 SF industrial building in Huntington Beach.  There was a new tenant moving into the space, and our client was the architect in charge of the tenant improvements.  He wanted a REVIT model of the existing conditions of the building, so we decided the laser scanner was the perfect tool for the job.

It took about 2 hours to scan the entire building:  Interior, Exterior, and Roof.  In addition to the scan, we always take some traditional measurements as a double-check to make sure the scan is accurate, and also to capture any data that the scanner might have missed due to obstructions in the way.  When the scan was completed, we had a point cloud model that looked like this:

Building exterior including roof detail and parking lot (yeah it gets everything)

A portion of the interior scan

Next came the much more time-consuming part – turning this point cloud into a REVIT model.  Our REVIT skills are rapidly improving but still not nearly where they could be, so it took us about 40 hours to model the building to the level of detail needed by our client.  Here’s a couple of those same perspectives in the finished REVIT model: