The simple truth is, scanning is the only cost-effective solution to collect the existing world.

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

Laser scanning is the only way to do it.

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

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

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

2004: 360-Degree Scans

The first 360-degree scanners came onto the scene around 2004. Before that, if you wanted to scan something above your mind, you had to tilt the scanner back and scan at a steep angle, because so many only had a 120-degree scan ability on the vertical axis. Several companies came out with full straight scanners about this time that managed to get much easier.

2006: Time-of-Flight Scans

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

At our firm, our first scanning projects were roads. In a very complicated area, we would scan 1"X 1". The time-of-fight scanners back then could collect 4,000 points per second. Now they can 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 develop a �-inch x �-inch pattern at a distance around 100 feet. This 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 almost anything in an acceptable about of time.

Present: Scan to BIM

Today, the big research money is certainly going towards Scan to BIM technology, which converts billions 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. (No more than this may seem, it is just a huge advancement.) This program may also recognize pipes and model them automatically about 50% of the time. (Another major advancement.)

Now many of the pipe programs are receiving to the same place and advancing the ball. Currently, we are at what I call the "Model T Ford" in software programs, but each year the programs progress.

The next evolution

Having now scanned may very complex areas in industrial sites, we have 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 process is so difficult that when an installer sees a less strenuous path, he generally takes it.

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

There is not a lot of motivation to do a completely new survey. But in case a design team takes these documents and models them into their computer programs, they're unknowingly creating multiple problems for the contractor on the brand new job.

We recently took a set of asbuilt documents for a complex project, modeled them and compared them to the point cloud to do a clash detection to determine potential interferences. The results was eye opening.


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

With the utility and cost of laser scanning, it could be best if you use one on every renovation project. If for BIM Surveys Warwick , insurance! Just one single field fit will often cost far more than 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 undoubtedly be. We have found conflicts that could have taken up to $100,000 to repair if they needed to be field-changed during construction. Some were fatal flaws in the mandatory design clearance which could not have been achieved and a completely new design could have had to been submitted.

Scanning to BIM is a big and extremely important part of surveying. Right now, it's the design software that is trying to meet up with the scanning potential. Already this year, several new programs have recently come out that are much better at accepting point clouds and computer models, but they still have quite a distance to go.

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

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