Scan to BIM: The Evolution of Scanning Technology

The simple truth is, scanning is the only cost-effective way to collect the prevailing world.

You simply can't get into a cathedral, petroleum refinery, or metropolitan multi-use entertainment facility and measure with rulers and be prepared to get the accuracy you have to confidently design renovations.

Laser scanning may be the only way to do it.

Up until recently, BIM users would take a group of "asbuilt drawings" put them into a 3D modeling program and develop a computer model to work from. Now, after many years to do that, the harsh realization has surfaced that there are many discrepancies between your "record drawings" and the actual environment to be constructed.

If it's sheetrock and wood, it can be adjusted to fit. But if it's glass, steel, concrete or mechanical equipment, a seemingly small error can grow very costly as it is much harder to warp and bend. (Putting expensive new equipment into a location that is too small is a nightmare for the installer, designer, engineer and the insurance company.)

These new 3D laser scanning technologies have dramatically changed the surveying industry - plus they have changed it fast. But to really understand the evolution, let's have a step back....

2004: 360-Degree Scans

The first 360-degree scanners came onto the scene around 2004. Before that, in the event that you wanted to scan something above your head, you had to tilt the scanner back and scan at a steep angle, as most only had a 120-degree scan ability on the vertical axis.  https://surveyorwarwickshire.co.uk/best-building-information-modelling-warwickshire/  arrived with full straight scanners concerning this time that made it much easier.

2006: Time-of-Flight Scans

Another evolution was time-of flight scanners. In 2006, a time-of-flight scanner took about 45 minutes to one hour for a complete 360-degree scan. In the event that you could do 8-10 scans each day, you were doing very well. Today, the same can be achieved in about 12-15 minutes, with regards to the density you want a scan.

At our firm, our first scanning projects were roads. In an exceedingly complicated area, we would scan 1"X 1". The time-of-fight scanners in the past could collect 4,000 points per second. Now they are able to easily collect 50,000 points per second!

2008: Phased-Based Scans

Today's phase-based scanners collect 2,000,000 points per second and can create a �-inch x �-inch pattern far away around 100 feet. That is incredible and as fast and dense because the average user needs. The hardware will eventually progress, faster and cheaper, but phase-based scanning works well, stable, and provides the ability to scan just about anything in a reasonable about of time.

Present: Scan to BIM

Today, the big research money is certainly going towards Scan to BIM technology, which converts vast amounts of points in the point cloud into useful data.

Several companies have begun addressing this including small independent companies like Pointools, which came up with a means for scanners to recognize flat surfaces. (As small as this may seem, it is just a huge advancement.) This program may also recognize pipes and model them automatically about 50% of that time period. (Another major advancement.)

Now lots of the pipe programs are receiving to exactly the same place and advancing the ball. Currently, we are at what I call the "Model T Ford" in software programs, but every year the programs get better.

The next evolution

Having now scanned may very complex areas in industrial sites, we've had a chance to compare them to the asbuilt drawings. In the horizontal view, they are generally close geometrically to the actual. But in their vertical axis, the pipes and duct work in the asbuilt drawings are rarely correct.

There are many known reasons for this, but frequently it is because the procedure is so difficult that when an installer sees an easier path, he generally takes it.

"Record drawings," or asbuilt surveys, are rarely done following the work is complete. Typically, the conversation goes something like this: "Listed below are the look drawings. Redline any changes that you made."

There is not lots of motivation to do a totally new survey. But if a design team takes these documents and models them to their computer programs, they are unknowingly creating multiple problems for the contractor on the brand new job.

We recently took a couple of asbuilt documents for a complex project, modeled them and compared them to the stage cloud to do a clash detection to find out potential interferences. The outcome was eye opening.

Several pipes, ducts, waterlines or fire lines in the ceiling were in the place shown on the record drawings. If these documents have been used, the MEP contractors would have spent ten times our fee "field fitting" the new utilities inside the old.

With the utility and cost of laser scanning, it would be smart to use one on every renovation project. If for nothing else, insurance! Just one single field fit will often cost far more compared to the scan itself.

If you scan the surroundings and put the proposed design into the point cloud, you can tell in just a few minutes where in fact the major interferences will be. We've found conflicts that could have taken up to $100,000 to fix if they needed to be field-changed during construction. Some were fatal flaws in the mandatory design clearance that could not need been achieved and a completely new design would have had to been submitted.

Scanning to BIM is a big and intensely important part of surveying. Right now, it is the design software that is trying to catch up with the scanning potential. Already this season, several new programs have come out that are far better at accepting point clouds and computer models, however they still have quite a distance to go.

Not having a design predicated on a laser scan of the actual environment is really a risk that few designers should take. I know I wouldn't want to tell an owner that there surely is a construction problem that could have been avoided with a cheap laser scan.

Laser scanning has evolved from a "luxury" to a best practice and it's really not a step that any prudent designer should skip.