As-Built Point Cloud Scans Enable Accurate Record Keeping

There’s a scene in the classic 80s flick, Ferris Bueller’s Day Off, in which the three main characters visit the Art Institute of Chicago. One character, Cameron, becomes engrossed in the Georges Seurat masterpiece, A Sunday on La Grande Jatte—1884, which was painted in a style known as “pointillism.” As Cameron studies the painting more and more closely, it becomes evident that it is made up of individual dots. Only when viewed from a distance does the subject become apparent.   

Similarly, 3D maps and models are made up of individual data points.  A point cloud is a massive collection of virtual data points, with each one representing actual points in the real world. These millions of individual data points, taken together, create a usable dataset. Using software to model physical objects in digital space makes point clouds imminently useful.

Data is collected by laser scanning. Laser scanners have LiDAR sensors that use rapid infrared pulses to collect hundreds of thousands of measurements each second. The closer the scanner to the object, the finer the detail and the greater the accuracy.

Each data point has its own xyz coordinate. (When you add an RGB camera, you get 4D capability.) When input into mapping and modeling software, point clouds have the ability to produce almost unlimited applications, including accurate building information models (BIMs), digital twins, and as-builts for the construction industry.

As-Builts Serve Many Functions

As-builts created from laser scans are infinitely more accurate and useful than traditional as-builts created by hand. In addition to keeping a record of a construction project, 3D as-builts:

• Help architects, designers, and others on a team visualize a project. Facilitating collaboration among farflung parties saves time and money. With accurate scans and models, informed decisions can be made without site visits.
• Allow more control and monitoring. Frequent scans can reduce construction delays, detect flaws, and offer clash detection. Done frequently, as-builts can catch problems–such as building elements that won’t mesh or align properly–in the early stages when they are more easily fixed.
• Provide a visual record to document all changes made to the original building plan.
• Let everyone communicate more clearly, which is especially helpful as additional contractors come onsite. Having a current as-built for everyone to work from reduces the chance of miscommunication and clearly demonstrates the state of the project. In fact, if you are coming onto a work-in-progress, having a scan of the existing work can protect you if a dispute arises later.
• Reduce the necessity of repeat site visits for more data collection. The sheer amount of data collected during the initial laser scan decreases the likelihood that a revisit to the site will be necessary in order to get more info. All of the location data is stored for reassessment or to enable redesign, if necessary.
• Provide an accurate plan of a building that is slated for renovation, expansion, or demolition. This means you do not have to rely on old, possibly out-dated records.
• Offer a safe means of mapping and modeling fragile, historic structures. Because 3D scanning is non-invasive, measurements and structural details can be depicted without causing harm. And because it can be done remotely, no one has to risk life and limb entering an unstable structure.
• Protect you in case of a dispute down the road.

Keeping Accurate Records with As-Builts

As-builts are amazing tools for documenting a project from the design stage through completion. These same as-builts can be used to maintain the building in the future, provide guidance during renovation, and can even be useful during its eventual demolition.

One of the main benefits of as-builts is the proof they offer in case of a dispute. Disputes can arise years later. One might assume that the statute of limitations would start upon completion of a building, but the clock actually starts when a defect is discovered or an injury occurs. This means that technically, a lawsuit can be filed decades after construction.

Fortunately statutes of repose have been instituted, which definitively bar claims a set number of years after a structure’s completion, or after a substantial portion has been constructed. However, statutes of repose vary from state to state, with some being as long as 15 years. It pays to keep organized, voluminous records of every project.

After such a long period of time, you cannot rely on memory or sloppily maintained records; you need to have watertight documentation. When you have to prove that an alternative building material was okayed, a change of design was approved, or a specific contractor came onto the project before work occurred, you will be glad to have organized, complete records.

Complete records will include contracts, permits, meeting notes, emails and other correspondence, and specific details, such as the type of caulk and color of paint used. Whether or not such things were followed to the letter may be debatable, especially if years have transpired. However, if you have a series of as-builts completed during the construction project as visible evidence, you have ironclad proof.

Make 3D As-Builts Part of Every Project

With so much at stake on every construction project, you should use every tool at your disposal to make sure work goes smoothly and that the final structure satisfies the client’s vision. More than just a picture of an end result, as the name implies, as-builts serve a wide variety of functions during the building process and long after completion.