Solve Labor Shortages! Easy 3D Construction with LRTK on Your Smartphone

Introduction: The challenges of labor shortages and improving site efficiency

In the construction industry today, labor shortage and improving on-site efficiency are major challenges. As veteran workers age and fewer young people enter the industry, the average age of site technicians is trending upward. In the 2020s it has been said that over 30% are 55 or older and only about 10% are 29 or younger, raising concerns about a future shortage of skilled workers as large numbers of experienced personnel retire. To handle workloads under these conditions, initiatives to reduce labor and improve productivity—that is, running sites efficiently with fewer people—are essential.

At the same time, DX (digital transformation) of construction sites is being promoted, typified by the Ministry of Land, Infrastructure, Transport and Tourism’s initiative *i-Construction*. Interest in digital technologies is growing even among small contractors and municipalities, but many are hesitant to adopt them thinking, “Don’t I need specialized knowledge?” or “Aren’t expensive devices required?” One promising approach is “3D construction.” This new method uses 3D data and ICT technologies across surveying, design, and construction management, and is expected to be a trump card for solving labor shortages and improving site efficiency. This article explains the basics of 3D construction, the benefits of adoption, concrete usage methods and case studies, and the challenges at introduction and how to overcome them. Learn the key points of 3D construction that even small sites can start right away, and at the end we introduce a tool you can start using easily on a smartphone: LRTK. If you are interested in DX but have not taken the first step, please use this as a reference.

What is 3D construction and why is it attracting attention?

3D construction moves beyond traditional methods that rely on 2D drawings and craftsmen’s intuition, using 3D data and ICT (information and communication technology) throughout the construction process. From surveying and design to construction, inspection, and maintenance, using digital 3D models and data at each stage enables automation, precision, and efficiency. In *i-Construction*, promoted by the Ministry of Land, Infrastructure, Transport and Tourism since 2016, this 3D construction (ICT construction) is a pillar of the productivity revolution, aiming to reduce manpower and time while ensuring quality.

The severe labor shortage mentioned earlier is a major reason 3D construction is gaining attention. With rising construction demand, manpower-based approaches have reached their limits, so digital technology is increasingly needed to “achieve high-quality construction with fewer personnel.” 3D construction also contributes to on-site safety improvements and workstyle reform. Automated or remotely operated heavy machinery can reduce the need for people to enter hazardous situations, and data-driven workflow reductions can help correct long working hours. Moreover, introducing digital technology can transform construction sites—once avoided as “three K’s” (difficult, dangerous, dirty)—into attractive workplaces with a “new three K’s” of “good pay, paid leave, and hope,” making it easier to retain young workers.

In short, 3D construction is a construction style where “data drives the site.” Digital data complements or replaces areas that relied on experience and intuition, allowing anyone to perform high-precision construction. This trend is expected to accelerate, and in fact the ministry announced a policy to make ICT construction essentially mandatory for public earthwork projects from fiscal 2023. In other words, 3D construction is becoming standard technology across the industry, not just at advanced sites. Therefore, rather than sitting on the sidelines thinking “this doesn’t concern us yet,” small and medium-sized companies and municipalities should see early adoption as valuable.

Differences between traditional construction management and 3D construction

So what concretely differs between traditional construction management and 3D construction? The main differences lie in how information is handled and the level of digitalization of work processes. Key differences include:

• Surveying and design: Traditionally, craftsmen used transits and levels to survey sites and performed design and quantity calculations on 2D drawings. Because measurement points were taken manually and then drafted, the obtainable information was limited, and complex terrain often relied heavily on craftsmen’s experience. With 3D construction, detailed terrain data are captured using 3D surveying equipment (drone photogrammetry, 3D laser scanners, GPS surveying instruments, etc.). Design is performed on the resulting 3D terrain model, and design data itself is created as a digital 3D model. This enables plans that accurately reflect actual terrain from the design stage.

• Construction: Traditional construction relied on paper drawings and layout markings on the site, with craftsmen operating heavy machinery and tools. The quality often depended heavily on veteran intuition, and rework was common. In 3D construction, created 3D design data is integrated into machinery and surveying equipment. For example, ICT-enabled construction machines—bulldozers and excavators equipped with GPS and sensors—can automatically control blade height based on 3D design data to perform precise excavation and grading without operator assistance. On site, workers can constantly view 3D models on tablets or smartphones, reducing the risk of misreading drawings. In other words, 3D construction sites are places where “machines move automatically” and “humans work while looking at data.”

• Construction management and inspection: Traditionally, after construction the surveying team would perform cross-section surveys and elevation measurements to verify as-built conditions and compare them with drawings for inspection. These tasks required time and manpower, and it was uncertain whether all areas had been checked until measurements were taken. In 3D construction, you can capture current 3D point cloud data during or after construction using drones, terrestrial scanners, or LiDAR-equipped tablets, and verify as-built conditions digitally in their entirety. Overlaying the design 3D model and the as-built point cloud makes it possible to detect discrepancies and excesses across wide areas at once. Local errors that people might miss can be highlighted by color-coding. Report preparation is also simplified as quantities and drawings are automatically generated from the data, greatly reducing the effort needed to produce inspection documents.

• Information sharing: Traditionally, site agents and managers reported progress with daily photo albums and paper drawings, explaining to subcontractors or owners as needed. Such explanations required experience, and there was often a time lag when conveying information to distant parties. With 3D construction, site 3D data and progress models can be shared with stakeholders in real time via the cloud. Office staff can check site point cloud models and machine operation logs remotely and issue instructions from afar. Visualized 3D information is intuitively understandable and useful for explanations to owners and local residents.

Thus, 3D construction stands apart from traditional construction management in that it “manages the site with data.” Data and machines support and reproduce tasks that used to be dependent on individual craftsmen, enabling standardized quality and dramatic improvements in work efficiency. Adoption does introduce new hurdles such as creating 3D data and preparing equipment, which are discussed in the challenges and countermeasures section below. Next, we’ll look at the representative technologies and functions that 3D construction makes possible.

What can you do with 3D construction? (point cloud data, AR, as-built management, etc.)

By introducing 3D construction, various advanced methods can be used on site. Here we highlight three particularly notable technologies and applications.

• Understanding and measuring the current site with point cloud data: The starting point of 3D construction is the use of point cloud data. Point cloud data is a collection of countless measured points acquired by laser scanners or photogrammetry that digitally reproduces site terrain and structures with high accuracy. For example, aerial surveys by drone can rapidly produce a wide-area terrain point cloud model. On the ground, recent LiDAR built into smartphones and tablets makes it easy to scan surrounding point clouds. Because point clouds are measurement data that capture reality almost as-is, they let you grasp subtle bumps and depressions of complex terrain or structures that were previously difficult to measure. You can freely measure distances, areas, and volumes from acquired point clouds—for instance, calculate excavated soil volumes by comparing point clouds or analyze slope angles on the point cloud. Digitizing the current condition entirely removes worries about “I forgot to measure that” or “I forgot to record it.” Point cloud technology, which lets anyone easily perform precise surveying, is the foundation of 3D construction.

• Intuitive construction support with AR: AR (augmented reality) is also a powerful tool for 3D construction. AR technology can overlay design data onto the real world through a tablet or smartphone screen. For example, in paving work, displaying the completed design model in AR makes it instantly clear how much fill is needed to reach the design elevation. In piping work, a translucent 3D model of buried pipes can be displayed on the ground to check excavation zones and possible interference with other buried utilities. Recent smart devices have dramatically improved GPS and sensor accuracy, and when combined with dedicated applications they can achieve cm-level precision AR positioning (cm level accuracy (half-inch accuracy)). The design model stays aligned even while walking around the site, making it feel as if the completed structure exists there. AR makes the design more “visible,” which is helpful during as-built inspections with clients or as a training tool to show site staff work procedures. If 3D records of previously buried pipes or cables are saved, future work can see through the ground with AR to reduce the risk of accidental damage. AR construction raises everyone’s spatial awareness regardless of experience level, leading to safer and more accurate work.

• Streamlining and enhancing as-built management: As-built management is the quality control process of verifying that completed structures or embankments match the design shapes and dimensions. Digital technology is very effective for this process in 3D construction. Using point cloud data as mentioned earlier, you can fully verify post-construction terrain. For instance, in road work you can overlay the design completion model and the acquired point cloud and display deviations as a heat map—areas matching the design in blue to green, and over-excavation or insufficient fill in red—so acceptability is instantly apparent. This finds errors that partial inspections would miss and helps prevent rework. Computing differential volumes on software reveals concrete correction amounts like “add X cubic meters of soil to meet the design” instantly. Cross-section drawings and tables for reporting are automatically generated, greatly shortening time to prepare inspection documents. If you attach global coordinates (latitude/longitude in a geodetic datum) to point clouds and photos, the data is useful for future maintenance. For example, leaving inspection records of a bridge or tunnel with 3D data allows accurate reproduction of the same location for later inspections and comparisons of changes over time. In this way, 3D construction data become assets after project completion and add value to long-term infrastructure management.

These are the main functions that 3D construction enables. Related technologies such as remote monitoring of heavy equipment operation and VR-based construction planning simulation continue to advance daily. The key point is that “using data and digital technology can make site work smarter.” Even people with little site experience can let machines do precise excavation, or complete all surveying alone—effects that directly contribute to labor and effort reduction. Next, we’ll look at real-world case studies and specific application scenes that utilize these 3D construction technologies.

Case studies and on-site application scenes

Even if you understand the concept of 3D construction, it may be hard to picture how it is actually used on site. Here are examples of concrete application scenes to demonstrate the usefulness of 3D construction.

• Case study 1: Streamlining earthwork quantity management and as-built verification: In a medium-sized site development, supervisors and surveyors traditionally spent days conducting cross-section surveys to calculate earthwork volumes. After switching to 3D construction, they could rapidly acquire the as-built point cloud using drone aerial surveys and smartphone LiDAR scans, and complete volume calculations and as-built verification on the same day. Sharing point cloud data in the cloud allowed remote design staff to check instantly. As a result, personnel dedicated to surveying dramatically decreased, and one person could manage as-built verification. Visualizing errors with point cloud heat maps enabled early detection and correction of rework areas, contributing to improved quality.

• Case study 2: 3D recording of buried pipes and AR use: In a municipal sewer replacement project, accurately preserving replacement locations for future maintenance was required. Traditionally, only paper records were kept, but on one site 3D scanning with a smartphone during open-cut work converted pipe locations and depths into point cloud data and stored them in the cloud. After backfilling, the buried pipes can be shown translucent on a tablet using AR, allowing managers to “see what is invisible.” This practice achieved zero accidental breakages due to excavation, and future repairs can precisely locate utilities. No special markers or veteran intuition were needed—anyone can intuitively detect and confirm buried assets, which was highly valued.

• Case study 3: ICT adoption on small sites: A sole proprietorship civil contractor with only a few employees handles small site development and exterior works. They couldn’t afford a full-time surveyor and site management was always uncertain. As a simple 3D construction approach, they equipped a backhoe with an aftermarket machine guidance device, enabling operators to check design and current excavation depth on an in-cab monitor while working. They also surveyed sites themselves before and after construction using a smartphone and RTK receiver to create 3D models. After adoption, one machine and one operator could perform high-accuracy excavation, and tasks that used to take half a day for site grading were completed in a few hours. ICT technologies that work on small sites improved productivity and gave them confidence that “digital construction is doable for us too.”

As shown, 3D construction is applicable regardless of site size. While it can be fully utilized in large infrastructure projects, the point is “small sites can also achieve significant effects with ingenuity.” The ministry has recently prepared ICT construction guidelines for small projects to support adoption by small and medium-sized enterprises. For example, criteria such as “ICT use is acceptable for earthwork volumes of around 100 cubic meters or less” have been indicated, and systems are being put in place to allow contractors to adopt 3D construction by request. It’s a misconception to think “we only have small sites so it doesn’t apply”; in fact, 3D construction benefits are often greater where labor is limited. The growing number of local, practical examples of digital technology adoption is encouraging for those considering introduction.

Challenges of 3D construction and how to overcome them

Even convenient 3D construction has several challenges at introduction. Here are frequently heard challenges and suggested ways to overcome them (countermeasures).

• Cost concerns: Cost is often the first objection. Full-scale equipment like 3D laser scanners and ICT-enabled machines can be expensive. A useful countermeasure is to start with inexpensive and easy-to-use equipment. For example, products that enable high-precision surveying using a smartphone + compact GNSS receiver, or simple machine guidance devices that can be retrofitted to existing machines, are now available. You can also consider phased introduction such as renting equipment only when needed or outsourcing drone surveys. There’s no need to procure everything at once—start small according to purpose and scale up gradually to control costs. Also check for subsidies and municipal support programs that may be available.

• Technical skill concerns: There are worries like “I don’t have expertise with 3D or ICT—can we really use it?” While some tasks require different software operations and data processing than before, modern tools have become more intuitive with refined UIs. Some software allows point cloud processing and surveying with a smartphone app interface, and there are cases where site personnel could use them without formal training. Systems designed for fieldwork are made to be usable by non-specialists. If concerns persist, take advantage of manufacturer or dealer training and support services. In the early stages, have experts provide advice and learn on the job (OJT) so your staff can operate independently over time. If you have digitally savvy younger staff, actively involve them to lead DX from a young cohort.

• Creating and operating 3D data: 3D construction requires 3D design data (BIM/CIM models) as a foundation. People often say “converting design drawings to 3D is time-consuming” or “we’re not used to CAD on PCs.” There are two countermeasures. One is to use external resources—services that create 3D design data or design support software with BIM/CIM compatibility are increasingly available. Outsourcing parts of the work to specialists rather than trying to do everything in-house is often faster. The other approach is that you don’t need a perfect 3D model from the start—use 3D in only parts of your workflow. For example, you can keep design drawings as 2D but combine them with current point clouds for planning, or use 3D only for as-built inspections. Gradually expand the scope as you gain experience and see the convenience of 3D.

• Internal understanding and securing human resources: New technology often meets internal resistance. Veterans may be cautious, saying “the old ways are fine” or “I don’t trust digital.” The best remedy is to accumulate small successes to persuade others. Try 3D construction on a single site and present concrete results such as “work time was reduced by X%,” “the site ran with fewer people,” or “no quality issues were found.” Share outcomes through site tours or internal presentations to foster positive attitudes. Developing human resources to champion DX is also important—send young employees to external seminars or hire ICT-savvy people to form an internal digital promotion team. To obtain management buy-in, share a sense of urgency based on national policies (ICT mandatoryization or future changes to competitive bidding criteria) so stakeholders understand that “not doing this now may risk future contract opportunities.”

As shown above, challenges to introducing 3D construction can be overcome through phased implementation and careful support. Don’t try to change everything at once; start digitizing where you can, verify results, and broaden internal and external understanding. Fortunately, guidelines and educational support from government agencies have progressed, making adoption easier than before. Rather than being intimidated by perceived difficulty, take the first step.

Summary: 3D construction that small sites can start right away

We’ve covered the overview of 3D construction, use cases, and key points for introduction. 3D construction is not only for large companies or big projects—it delivers great benefits even for small contractors and municipal small sites. In times of labor shortage, leveraging digital technology to achieve high-quality work with limited resources is essential.

Start DX with small steps. For your next site, try drone or smartphone-based as-built surveying, or hold meetings with craftsmen using 3D models on a tablet instead of paper drawings. Even if it feels awkward at first, once you experience “it was easier than expected” or “efficiency improved,” that will build confidence. Those experiences will support DX on subsequent sites and spread within your company. Ministry statistics indicate that companies that use ICT to improve productivity tend to see increases in orders and profit margins. In other words, 3D construction is an investment, not a cost, and early adopters can gain first-mover advantages.

For younger staff, sites that use digital tools are attractive and rewarding workplaces, which positively affects recruitment and company vitality. If you’ve hesitated thinking “our scale is too small for 3D construction,” please try digital construction where you can. Small successes will be the first steps toward major site reform.

Finally: Make 3D construction even easier with LRTK. Why not start with surveying?

If you want to start 3D construction, it’s recommended to begin by capturing the site in 3D. A helpful solution for this is “LRTK,” which enables easy, high-precision surveying and point cloud scanning using a smartphone.

LRTK is a portable surveying device that mounts a compact RTK-GNSS receiver (positioning terminal) on a smartphone or tablet such as an iPhone or iPad. By attaching a pocket-sized receiver weighing just a few hundred grams to your smartphone, satellite positioning errors can be corrected to within a few centimeters, allowing centimeter-level positioning (cm level accuracy (half-inch accuracy))—which previously required specialized equipment—to be accessible to anyone. A major feature is that the dedicated app, working with the smartphone’s built-in LiDAR and camera, allows one person to walk the site and capture precise 3D point clouds. For example, using LRTK you can scan a 30 m (98.4 ft) square site in a few minutes and immediately generate a 3D terrain model. Acquired data are automatically saved to the cloud and can be checked from the office PC in real time.

LRTK also provides all-in-one functions for the AR display and as-built management described earlier. If you upload the design 3D model to the cloud in advance, you can accurately project that model in AR on the phone screen at the correct position on site. Because the model does not drift while walking around, LRTK makes it easy for anyone to perform layout and alignment. Saved scans of buried assets enable the aforementioned AR see-through function with a single tap, allowing safe site understanding without trial excavations. The app also supports as-built analysis, automatically creating heat maps by comparing acquired point clouds with design data. Even without expert knowledge, a single button press can tell you “how much and where to fix to meet the design,” simplifying inspection preparation.

With LRTK, surveying, construction management, and reporting can be completed with just a smartphone. There’s no need to carry heavy equipment—the portability of a pocket device is highly attractive to busy site managers. Even in mountainous areas with no mobile coverage, LRTK can receive Japan’s positioning satellite “Michibiki” high-precision augmentation signals (CLAS) directly, maintaining high-precision positioning offline. It is also suitable for urgent surveying at disaster sites or measurements in GPS-shadowed locations (under bridges, etc.), making it a reliable ally in critical situations.

Thus, LRTK is designed so that “anyone, anywhere, immediately” can take the first step in 3D construction. If you’re wondering where to begin, try high-precision smartphone surveying with LRTK. Scan the site to create a point cloud and experiment with as-built checking and AR—you’ll likely be surprised by the difference from conventional methods. For small sites especially, introducing digital surveying with LRTK can help you experience the benefits of solving labor shortages and improving efficiency.

3D construction is not difficult—using the right tools, you can start tomorrow with just a smartphone. LRTK can be your reliable partner. Bring 3D construction to labor-short sites step by step. The digital revolution that will change the future of sites is right around the corner. From today, why not take on site DX with a smartphone in your hand?

(For details and introduction methods for LRTK mentioned in this article, please refer to the manufacturer’s official website and materials.)