Beginner-Friendly and Easy! Point Cloud As-Built Management to Make Your Site Three Times Faster!

Many beginners and young engineers may feel that as-built management on site seems difficult... As-built management is the important process of checking and recording whether the finished shape after construction matches the design. However, conventional methods require time for measurement and recording, and can be tough for those who are not yet accustomed. Lately, a new approach using point cloud data has attracted attention for as-built management. By using point clouds, anyone can easily perform as-built management and significantly speed up on-site work. This article gently explains the basics — what as-built management is and what point clouds are — and how simple and efficient as-built management using point clouds can be. We introduce, in an easy-to-understand way for beginners, the differences from conventional methods, an image of the concrete operations, error visualization by heat maps, and the manpower and time savings achieved by adoption. We also touch on easy introduction cases using smartphones and tablets, points for cloud utilization, and what to do if things don’t go well. At the end of the article, we introduce a simple high-precision surveying method anyone can do using LRTK (smartphone × small GNSS). Even if you are unfamiliar with digital technology, don’t worry! Embrace point clouds for as-built management and grab tips to make your site operate at “three times the speed.”

What is as-built management? A gentle explanation of its importance

First, let’s briefly review what “as-built management” is. As-built management is the work in civil engineering and construction of checking and recording whether the finished shape of structures or terrain after construction matches the instructions in the design documents. For example, in road work you measure pavement thickness and width; in land development you measure slopes and heights of fills and cuts — confirming that the completed work meets the specifications. It is an essential process for quality assurance and inspection of the finished product, and site supervisors and construction management engineers carry this out responsibly.

As-built management is important because once construction is complete, it is difficult to fix things later. Many parts of a site can only be measured during construction, such as the ground shape before concrete is poured and filled, or the depth of trenches before pipes are buried. If these parts are not properly recorded at each construction stage, you may not be able to confirm later whether they were done correctly. If a defect or problem is discovered in the future, relying only on photos or notes taken immediately after construction feels precarious. To avoid regrets like “We didn’t properly measure that area…,” as-built management requires complete and reliable records without omissions.

Traditionally, as-built records have mainly been kept using photographs, hand-drawn drawings, and measurement field notebooks. Methods include taking photos of construction progress and compiling them into an album (photo ledger), or measuring specified points’ heights and widths with scales and measuring instruments and recording them. While these methods can preserve the bare minimum information, they have the problem of being prone to “forgotten photos” and “forgotten measurements.” On busy sites people can accidentally forget to take photos, and during final document compilation after completion you might break out in a cold sweat thinking, “Oh no! There’s no photo of that part…” Also, photos only preserve information within the captured frame, and some areas may be hard to see due to angle or lighting; without a scale in the photo, accurate dimensions cannot be read later. Records based on sectional drawings (cross-sections and longitudinal sections) are merely lines connecting a few measured points, so they cannot capture bumps and hollows in unmeasured areas. As a result, you may discover later subtle distortions that drawings and photos couldn’t reveal, such as “The drawings looked fine, but the finished product is slightly warped.” Especially when a client or third party questions the as-built accuracy, having only photos and paper documents may leave you unable to sufficiently explain or prove the results, which can be frustrating.

Thus, conventional as-built management methods carry a risk of omissions and gaps. To avoid failing to fully document the results of hard on-site work, it is worth adopting a more reliable and comprehensive recording method. Enter the new approach: as-built management that utilizes three-dimensional point cloud data. Next, I’ll explain what a “point cloud” is in an easy-to-understand way for beginners.

What is a point cloud, and how do you acquire it?

Point cloud data is digital data representing the surface of an object as a multitude of points. Simply put, it is a large collection of points that shapes the target obtained by laser scanning or photogrammetry, with each point having XYZ coordinates (position information). Because each point has coordinates in three-dimensional space, the object or terrain shape can be reproduced like a “cloud of points.” Modern measurement devices can also capture color with a camera, so point clouds displayed on a PC appear as three-dimensional, colorized points that look photographic.

How is a point cloud acquired? There are several representative methods. One is using a device called a 3D laser scanner. Ground-based laser scanners mounted on tripods emit laser pulses at high speed from the device and measure distances to surrounding terrain and structures in a surface pattern to obtain many points. Another is UAV (drone) photogrammetry. A drone captures dozens of photos from the air, and dedicated software analyzes the photos to reconstruct a 3D model, producing point cloud data. Recently, it has also become possible to obtain point clouds simply with sensors built into tablets and smartphones. For example, some newer tablets include a LiDAR distance sensor that allows you to scan nearby areas with a handheld device to produce point clouds. In other words, even without specialized surveying equipment, you can obtain 3D data with some ingenuity.

What point clouds provide is a vast number of points, but their real value is as a “precise 3D record.” Because they digitally preserve an object’s shape down to the details, using point clouds for as-built management lets you record the post-construction shape exactly as it was. Supported by initiatives like the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction* (i-Construction), the movement to utilize point cloud data in construction as-built management is expanding. Advanced 3D measurement that used to be handled only by surveying specialists is becoming accessible to anyone on site thanks to technological progress and the miniaturization and cost reduction of equipment. So what concrete benefits does implementing as-built management using point clouds bring to the site? Let’s look at that in the next section.

Benefits of as-built management using point clouds

Incorporating point cloud data brings various benefits to as-built management. Here are the main advantages from a site perspective.

• Measurement omissions and re-measurement effort are eliminated: Once the as-built is recorded with a point cloud, you rarely need to go back to the site thinking, “We have to re-measure that area…” All necessary dimensions can be obtained from the 3D data. For example, if you are asked after completion to “tell me the height here,” you can click that point in the saved point cloud and instantly read the height. You won’t have to worry about missing measurements on site, which prevents omissions in measurement work.

• Understand the as-built as a surface rather than just points: Point clouds record the entire surface of the object as surface data. Traditionally, you had to infer the whole from a few distant measured points, but point clouds allow you to grasp the entire structure’s shape as a surface. If you overlay the design data (the model or drawings of the finished form) and the point cloud and compare them, you can immediately see subtle bumps and hollows in unmeasured areas. Creating a heat map that shows deviations with colors makes it easy to see at a glance which parts match the design and which are out of tolerance. This surface-based management, which evaluates wide areas at once, drastically improves the accuracy of as-built management.

• Preserve and utilize as-built as 3D data for the long term: Point cloud data is digital, so if stored in the cloud or on a PC, it becomes a valuable record asset for the future. Unlike paper photos or drawings, as long as the data exists, you can display and check the 3D model years later. You can extract arbitrary cross-sections or recalculate volumes as needed. For example, if you save the point cloud of the finished terrain, you can compare it years later during maintenance to check for changes. It is also useful for future renovation or expansion design studies, and serves as insurance against regrets like “We don’t have the records.” Digitizing as-built management into 3D data has great significance.

• Improved safety and work efficiency: Point cloud measurement is basically non-contact and can measure wide areas quickly, contributing to improved on-site safety. You can obtain data from a distance for steep slopes where people cannot safely enter, or areas where heavy machinery is operating, reducing measurement risk. Work time is also greatly shortened: there are cases where surveying that took half a day by manual measurement was completed in just a few minutes by machine. Being able to measure quickly and accurately creates room in the schedule. With superior precision, efficiency, and safety, point cloud as-built management is a strong ally for construction sites.

With all these benefits, what changes can you expect on site when actually adopting point clouds? Let’s look more concretely while comparing with traditional methods.

How is it different from conventional methods? How on-site work changes

Imagine how on-site tasks differ between point cloud as-built management and conventional methods.

In conventional as-built management, staff and surveying instruments are first deployed on site to carry out measurements. For example, to confirm the subgrade height of a road, staff walk to the measurement points, use a level (surveying instrument) and a staff rod to measure heights at intervals of several tens of meters, picking up points one by one. Because measurements are taken manually, the number of points that can be obtained at once is limited. Measured values are recorded by hand in field notebooks or later compiled in Excel. Afterwards, you compare with the design drawings to calculate deviations and, if necessary, create hand-drawn cross-sections and reports. Photograph-based records also required extra work, like taking photos on site and then organizing and pasting them into ledgers back at the office.

In contrast, point cloud as-built management dramatically changes the flow from on-site measurement to record creation. First, the personnel required for measurement is minimized. In some cases, one person can complete the measurement. For example, a drone flight can often be handled by a single operator, and ground laser scanning can be done by a small team that sets up and operates the device. Measurement is automated, so even large areas can be completed quickly. The large point cloud datasets are processed on a PC or in the cloud, and software can perform deviation detection and comparison with drawings at the push of a button. Tasks previously done by humans manually are handled instantly by computers, reducing human error.

Record creation for as-built management is also streamlined. Where you previously had to manually compile charts in a fixed format, point cloud data can automatically generate cross-sections and terrain profiles or produce inspection results with color maps. The process of printing and pasting photos into an album is unnecessary with 3D data. Attach the electronic data to a report, and you have objective and persuasive explanatory materials for the client. For example, when explaining “This fill was constructed with the design slope,” showing a cross-section from the point cloud or a heat map makes it obvious. Information that used to be communicated only verbally or with still images can be visually conveyed with 3D data, making it easier to gain approval from clients and supervisors.

Overall, switching to point cloud as-built management significantly changes how site work is done. You measure more while reducing manpower and time, and the comprehensiveness and accuracy of records improve. Even newcomers will be surprised, with the help of digital tools, to exclaim, “I can do as-built management this easily!” Next, let’s walk through an operational image of point cloud as-built management.

Operational image of point cloud as-built management (for beginners)

Here’s a step-by-step image of how as-built management using point clouds is performed, explained so beginners can understand.

• Preparation for measurement: First, prepare the measurement equipment on site. For drone use, plan the flight; for ground lasers, set up the scanner in a position with a clear view of the area to be measured. Recently, cases of attaching small sensors to smartphones or tablets for measurement have increased; in those cases, simply launch the dedicated app. There is basically no difficult machine operation — pressing the measurement button completes the preparation with simple operations.

• Acquisition of point cloud data: When measurement starts, automatic acquisition of surrounding 3D data begins. A drone captures the entire site from the air; a laser scanner emits lasers 360 degrees and captures reflected points. For smartphone measurements, you can scan the surrounding point cloud simply by walking around while holding the phone. Even without being an expert, moving the device as if surveying the site generates a fine aggregation of points (point cloud) in real time.

• Data processing and checking: The acquired point cloud can be displayed and checked on a tablet or PC on site. Some systems upload data from the device to the cloud as soon as measurement finishes, and a 3D model is created in the cloud after just a few minutes. Once the point cloud is displayed, do a quick check for missing areas (data gaps). If any parts are missing, you can perform additional scans to fill them in. Being able to verify the data quality on site prevents discovering deficiencies after returning to the office and having to redo work.

• Overlay with design data: After obtaining the point cloud, next overlay it with the design data for comparison. Load design drawings or 3D design models into the software and align them with the current point cloud. If the point cloud includes absolute coordinates (such as a global geodetic system), it will automatically align with the design coordinates; if not, you can align by specifying known control points or a reference plane. Once positioned, the computer will determine which parts are constructed according to the design and which are deviating.

• Visualize deviations with heat maps: After computing differences from the design, create an as-built heat map. If you color-code the differences between the point cloud and the design surface in the software, you get a color map that shows at a glance which areas meet standards and which are off. For example, areas within the design range might show blue to green, spots that are too high could be red, and low areas purple — visualizing deviations with a color gradient. Even beginners can intuitively understand from the heat map, for instance, “The red area looks like overfilling here, so we should trim it down.” You can of course check numerical values for each point (how many centimeters high or low), but color visualization makes overall trends much clearer.

• Obtain and share various measurement results: After assessing the overall situation with a heat map, inspect details as needed. You can measure the distance between any two points on the point cloud, and enclosing an area can automatically calculate fill or excavation volumes. The software performs these calculations instantly, so there’s no need for calculators or rulers. Save the results as reports on your PC or in the cloud. If uploaded to the cloud, supervisors or clients in the office can view the data in real time. Getting confirmation from your supervisor on the spot, “No problems!” provides assurance even for a first-time measurement.

That is the general workflow. It may seem difficult at first, but in reality the steps are simply “measure, compare, and check by color.” Dedicated software or apps guide you through the process, and following on-screen instructions is usually sufficient. Handling 3D data on-site is often much easier than taking paper notes and crunching numbers with a calculator. Now, let’s add a little more on the heat map that appeared in this workflow.

Visualize deviations instantly with heat maps

A heat map is a graphic that color-codes deviations between the point cloud and the design data. In as-built management, determining whether deviations fall within specified tolerances is important, and heat maps are very useful for that judgement. As mentioned earlier, changing colors according to the magnitude of error makes it easy to see acceptance and trends at a glance.

For example, if the difference between the design surface and the point cloud is within ±3 cm (±1.2 in), it might be shown in blue to green; areas with larger bulges may appear yellow or red; and areas dug too deep may appear purple. If green areas dominate, you can conclude “It’s roughly according to design,” while a few red spots indicate “We’ve overfilled a little here, so let’s cut it back.” With a heat map, you can intuitively grasp the as-built accuracy without reading long lists of numbers.

Heat maps are also effective explanatory materials for clients and other team members. Showing a red-colored section in a heat map is more immediately clear than writing “There is an overfill of +5 cm” in text. In modern ICT construction sites, attaching these as-built heat maps to reports or displaying them on large screens for stakeholders to review is increasingly common. As the phrase “visualization” suggests, making data easy to see helps build consensus on site. Point cloud data may sound technical and difficult, but representing it as a colorful visual like a heat map makes it easy for beginners and executives to understand.

Once you’ve visualized the site’s situation with a heat map, you only need to address the parts that require correction. If large deviations are found, discovering them early reduces rework. The ability to quickly run PDCA cycles is another advantage of point cloud as-built management.

Manpower reduction and time savings lead to “site three times faster”! Here’s why

As introduced so far, as-built management using point clouds greatly increases on-site productivity, especially through manpower reduction and time savings. If surveying and inspection that previously took three people a whole day can be completed by one person in a few hours, the work speed can be “three times faster or more” in practice.

Consider a site checking earth volumes. Traditionally, a team of two to three went outdoors, measured heights at points and took notes, and then returned to the office to calculate and map the results, which could take half a day to a full day. By introducing point cloud measurement, the measurement might be completed by a drone flight in 20 minutes, and data processing automatically in about 30 minutes, so everything is finished while still on site. Only one person is required, and other staff can be assigned to different tasks. This major time reduction and personnel savings are core strengths of point cloud technology.

Time savings come from the fact that “the amount of information captured in one go is on a completely different scale.” Manually you might measure at most one point per second, while laser scanners can capture hundreds of thousands of points per second. Drone photogrammetry covers wide areas in a single flight. In other words, the need to repeatedly visit the site because you couldn’t measure everything, or to slowly measure and stitch things together, disappears — measurements can be completed in one shot. Automation of data processing also plays a big role: software takes over tasks previously done manually, shortening work time. Newcomers, in particular, often spend a lot of time on unfamiliar calculations and drawing creation, but digitalization covers those tasks as well.

The manpower reduction benefit is also significant. With severe labor shortages in construction, the ability for one person to complete measurement and checks is extremely helpful. Fewer personnel required makes staffing easier and is also advantageous for infection control and safety management. Of course, the knowledge of experienced surveyors remains valuable, but using technology to make “anyone capable up to a certain level” raises the overall baseline on site. New staff who can use digital tools can work efficiently with veterans to maintain quality control.

By reducing the labor required for as-built management, you free up time for other important tasks: thorough pre-planning to improve quality, meetings with clients, and arranging the next processes. Being able to allocate the extra time generated by point cloud as-built management to overall site management improvement is a major advantage.

Easy to introduce with smartphones and tablets! Latest on-site cases

You might hesitate thinking, “We don’t have a high-performance 3D scanner or drone at our site…” But rest assured: cases of easily starting point cloud as-built management with familiar devices like smartphones and tablets are increasing.

For example, at some small-to-medium sites, measurements are performed using a smartphone equipped with a compact dedicated device. This device links with the phone to provide high-precision GNSS positioning and 3D scanning; the site staff simply walk around with it. In minutes you can capture the surrounding point cloud, and a 3D model and heat map appear on the phone screen. Tasks that used to require specialist contractors are now handled by young in-house staff using a smartphone app. Even first-time users can proceed using intuitive app screens, and some say it’s “fun like a game!”

In another example, tablets are used for as-built checks. A tablet like an iPad with built-in LiDAR sensors can scan small structures for as-built confirmation, or drone-acquired point clouds can be displayed on a tablet via the cloud for on-the-spot reviews with supervisors. Parts that were hard to understand from paper drawings or photos become obvious when everyone can rotate a 3D model on a tablet and say, “Ah, so it’s like this!” Even staff inexperienced with ICT found they could handle 3D data on a tablet the same way they view photos, making introduction smooth.

Such smartphone and tablet use cases are appearing everywhere. You don’t have to buy expensive dedicated equipment right away; starting with familiar devices lowers the barrier to entry. Hands-on experience reduces reluctance toward digital measurement, and once you see the effects, proposing full equipment adoption internally becomes easier. Doesn’t the idea of “your phone turning into a powerful as-built management tool!” sound exciting? Try using familiar tools to explore point cloud applications at your site.

Points for cloud utilization: easy data sharing

Cloud utilization is indispensable when discussing point cloud as-built management. Point cloud data tends to be large because of its high density, but using cloud services effectively makes data sharing and management smooth. Here are the key benefits and points for cloud use.

● Large data safely stored and instantly shared: Storing point clouds in the cloud prevents overloading your PC’s storage and allows access from anywhere via the internet. If you upload data captured on site directly to the cloud, your supervisor or colleagues can check the data in a browser by the time you return to the office. There’s no need to copy to a USB drive — you can share information between site, office, and client in real time.

● Viewable without special software: Using a cloud-based point cloud platform, not only contractors but also clients can sometimes view 3D data without dedicated viewers. Services that display 3D models in a web browser have emerged, solving the problem of “I can’t show it because the client doesn’t have the software on their PC.” This is convenient when reporting or negotiating as-built matters online.

● Offload processing to the cloud: Heavy point cloud analyses and heat map generation are increasingly performed by cloud services automatically. Even if your local PC is not very powerful, cloud machines can handle the processing. It is common to perform quick checks with a tablet or laptop on site and send detailed analyses to the cloud to wait for results. When choosing tools, check how well they integrate with the cloud.

● Security and backup: Cloud data raises security concerns, but many services provide encrypted communications and access controls, and if used properly they enable safe data sharing. Uploading to the cloud also prevents data loss if your PC fails — the cloud is effective backup for important as-built data.

With cloud use, handling point cloud data becomes much easier. However, in some sites uploading large files may be difficult due to network conditions. In such cases, perform minimal data checks on site and upload later from the office. The key is to use a system that provides “one-stop support from data capture to sharing, storage, and utilization.” Fortunately, many contemporary point cloud tools standardize cloud integration, so beginners should proactively use these features.

Troubleshooting: solutions for beginners’ concerns

When trying point cloud as-built management for the first time, you might worry, “Can I really use this well?” or “What if I fail?” Here are common stumbling points and remedies for beginners. If you get into trouble, remember these tips.

• The equipment and software seem difficult to operate… ⇒ Modern point cloud tools are surprisingly user-friendly. Dedicated equipment comes with easy-to-understand Japanese menus, and smartphone-linked products provide on-app guidance. The basic flow is usually just pressing buttons, so even those uncomfortable with PCs need not worry. Operation training often takes only a few hours, and you can start with the same feeling as using photo management software.

• The data volume is too large to handle on my PC… ⇒ If concerned, use cloud services. As mentioned, some systems automatically upload point clouds from your phone to the cloud and provide web-based viewing and analysis. With cloud streaming you don’t need to download all data to your PC, and sharing via cloud avoids the client being unable to open files on their machine. Choose tools that also handle data management for you, and beginners will have few handling problems.

• I’m worried about the accuracy… ⇒ Hearing about measurements with smartphones or simple devices may raise questions like, “Is the accuracy enough for as-built management?” But rest assured: recent advances in RTK-GNSS (high-precision positioning) and photogrammetric technology provide sufficient accuracy for as-built management. In fact, modern small GNSS receivers can achieve fixed solutions (stable RTK) with horizontal accuracy of approximately ±1–2 cm (±0.4–0.8 in) and vertical accuracy of approximately ±2–3 cm (±0.8–1.2 in). This rivals traditional total-station surveying. Software that automatically verifies as-builts by comparing acquired point clouds to design data has also become practical. If you’re uneasy, measure known control points together to verify errors as an on-site double-check. The Ministry of Land, Infrastructure, Transport and Tourism has provided example guidelines for as-built management using 3D measurement techniques, and following those guidelines will yield acceptable accuracy.

• What if the measurement fails… ⇒ Worrying that data captured on site turns out unusable is natural. That’s where real-time data checks and cloud sharing help. After acquiring a point cloud, always preview it on site to confirm no missing parts or errors. If you’re unsure, ask a supervisor or senior to check via the cloud. If defects are found while still on site, you can immediately re-measure. The reassurance that “you can retake it” is comforting for first-time measurements. If problems persist, consider contacting the manufacturer or a specialist; many vendors provide helpful support, especially since the government is promoting ICT construction.

In short, modern point cloud tools are designed with beginners in mind and include support mechanisms. You may hesitate at first, but after trying them you will likely find them easier and more convenient than expected. Take your time and get used to them step by step.

Closing: Try simple high-precision surveying with LRTK!

Have the appeal and ease of using point clouds for as-built management come across? Although it may seem daunting at first, the era when beginners can step into digital measurement has already arrived. Recently, high-precision measurement using a smartphone plus a small GNSS receiver has been especially notable — a prime example being LRTK. LRTK is a system where a small RTK-GNSS device is attached to a smartphone, enabling centimeter-class positioning and point cloud scanning without complicated settings. For example, simply walking around the site with a smartphone equipped with LRTK produces high-precision 3D point clouds quickly. You can immediately compare the acquired data with design data for as-built checks and share data with the office via the cloud — such advanced workflows are available to anyone.

Absolute-coordinate point cloud measurement, which used to require expensive fixed equipment or large drones, can now be done easily with palm-sized tools and smartphone apps like LRTK. The cost is much lower than traditional dedicated equipment, making adoption easier — a “one device per person” era is approaching. Small sites no longer need to give up because of cost. Even beginners who tried LRTK report, “I feel like I can record as-builts in 3D myself!”

3D and DX transformation of as-built management will continue to progress. It is likely that keeping three-dimensional as-built records will become the norm in the future. Gaining early experience on site will help differentiate your company and build client trust when the time comes. Please take the first step into point cloud utilization. With affordable and simple smartphone-based measurement tools already available, there is nothing to fear. Try it boldly for your first time — you’ll likely think, “I’m glad we implemented this!”

Thank you for reading to the end. With point cloud as-built management that beginners can start easily, let’s achieve threefold efficiency improvement at your site!