What is 3D Construction? The New Trend in On-site DX Enabled by LRTK

Introduction

The construction and civil engineering industries are rapidly advancing digital transformation (DX) aimed at improving productivity and efficiency. At the same time, challenges such as a shortage of experienced surveyors and an aging workforce are driving the need to reduce labor through digital technology. Among these innovations, "3D construction," which acquires and utilizes on-site information in three dimensions, is garnering attention as a core element of on-site DX (digital construction). Precise surveying that once required specialist surveyors and expensive equipment is being transformed by technological innovation into something anyone can handle. In this article, we explain what 3D construction is and explore how the emerging positioning and measurement technology LRTK is shaping a practical approach to on-site DX that anyone can implement.

Benefits Brought by 3D Construction

Recently, the use of surveying and design data in three dimensions at construction sites has increased dramatically. By capturing terrain and structures as point cloud data or 3D models and using them, it has become possible to visualize gaps between design and construction and to streamline verification of the as-built shape (the shape after construction). ICT construction promoted by the Ministry of Land, Infrastructure, Transport and Tourism (so-called *i-Construction*) also places great importance on the use of 3D surveying data. For example, it is becoming common to obtain detailed point clouds of existing terrain via drone photogrammetry or terrestrial laser scanners and to use them for earthwork volume calculations and construction planning. Introducing 3D data makes it easy to intuitively grasp site conditions that were not visible from drawings or figures alone, facilitating shared understanding among stakeholders. This contributes to improved quality and safety as well as shorter construction schedules. Furthermore, 3D surveying data is starting to be used in advanced technologies such as machine guidance (MG) and machine control (MC) for heavy equipment, creating workflows where as-built survey data and design models are directly reflected in construction. In this way, 3D construction is transforming the entire construction production process.

Challenges in Conventional Construction Management

While the value of 3D surveying and digital construction has become recognized, there have been several hurdles with traditional methods. High-precision surveying required specialized equipment such as total stations or high-end GPS surveying units and typically involved two-person teams including a surveyor. Detailed point cloud measurements using laser scanners or photogrammetry by drone involved high equipment costs and required advanced skills and dedicated software. As a result, smaller sites or sites with labor shortages often found it difficult to adopt these technologies despite interest. In particular, with an aging population of surveying technicians and a shortage of young personnel, reliance on human expertise for surveying and construction management has clear limitations.

In addition, using acquired 3D data on site required specialized knowledge such as coordinate transformation and data processing, making real-time information sharing and utilization difficult. Even if point cloud data were obtained, without processing on high-performance PCs the data could not be fully utilized, and in practice sites often reverted to verifying information on 2D drawings. In other words, to fully reap the benefits of 3D surveying and 3D construction, significant investment and expertise were traditionally indispensable.

What is LRTK? A New Technology Supporting On-site DX

Against this backdrop, LRTK has emerged as a solution that overturns conventional wisdom. LRTK is a next-generation positioning and measurement system that makes RTK-GNSS (real-time kinematic positioning) technology easily usable on a smartphone. By attaching a dedicated ultra-compact GNSS receiver to a smartphone or tablet, the usual meter-level errors in smartphone positioning can be dramatically improved to centimeter-level accuracy. In the RTK method, both a reference station (installed at a known point) and the rover (the point to be measured) simultaneously receive satellite signals; by canceling common error factors between the two, the rover’s position is corrected to centimeter accuracy. Performing this in real time allows any point to be positioned instantly with high precision. In recent years, network RTK using the Geospatial Information Authority of Japan’s electronic reference point network and centimeter-level augmentation signals (CLAS) from Japan’s QZSS "Michibiki" have become widespread, making high-precision positioning possible without setting up a dedicated base station. LRTK leverages these mechanisms and has succeeded in enabling precise positioning and 3D measurement to be completed with just a smartphone—something that previously required specialized surveying instruments.

LRTK consists of a small device that attaches to a smartphone (weighing only about 165 g) and a dedicated app, and is compact enough to fit in the palm of your hand and easy to carry. With integrated battery and antenna, you can take it out of your pocket on site and start surveying immediately. It is designed so that anyone can operate it with minimal instruction, allowing a single person to complete site surveying, measurement, and verification tasks. There is no need to transport heavy tripods or complex equipment, making the smartphone a true "universal surveying instrument."

Site Issues LRTK Can Solve

Let’s organize how LRTK can address the construction site issues mentioned above.

• Alleviating labor shortages: With LRTK, one smartphone and a small device enable a single person to handle everything from surveying to as-built verification, so sites lacking specialized surveyors can still cope. The intuitive operation means inexperienced young workers can use it after brief training, helping to mitigate workforce shortages.

• Improved surveying accuracy: Positioning errors that used to be on the order of meters with conventional GPS are reduced to centimeters with LRTK’s RTK positioning. This enables highly accurate stake-out and placement of structures, and allows as-built measurements to detect even small deviations. Reduced surveying error directly improves construction quality and reduces mistakes.

• Cost reduction: Costs for purchasing specialized equipment or outsourcing to surveying firms can be reduced. Since only a smartphone and the LRTK device are needed, initial investment is greatly lowered and maintenance costs are minimal. Preventing rework and additional work due to construction errors also contributes to total cost savings.

• Prevention of rework and redo: With LRTK, 3D measurement and verification can be conducted at any time during construction, allowing deviations or deficiencies to be identified on the spot. By overlaying design models with AR to check them, you can avoid discovering errors only after completion and having to correct them. Because construction can progress while staying close to the design, unnecessary rework is reduced, shortening schedules while ensuring quality.

Key Features of LRTK and Use Cases

LRTK includes a variety of functions that make on-site DX a reality. Here are its main features and concrete use cases.

• High-precision point cloud scanning: Using the smartphone’s built-in LiDAR sensor or camera, the surroundings can be scanned quickly to obtain high-density 3D point cloud data. The acquired point clouds are tagged with global coordinates (latitude, longitude, elevation), linking each point to real-world coordinates. Operation is simple: just walk while holding the smartphone. You can scan a wide area within minutes—for example, even a large slope can be recorded in about a minute. The scanned point cloud can be checked on-site immediately and used to measure distances, areas, and volumes. In disaster response scenarios, point cloud scanning helps quickly assess the volume of collapsed slopes or washed-away soil. It also allows safe recording of conditions in hazardous areas by scanning remotely. In civil engineering, it is used to calculate earthwork differences by scanning before and after excavation, or to keep digital records of finished terrain, among other applications.

• AR-based 3D model display: LRTK’s AR (augmented reality) functionality projects 3D models and drawing data created during design into real space, displaying them at full scale on the smartphone screen. Because models are placed based on high-precision positioning, no manual alignment is required and AR displays remain accurate. Simply load design data (for example, BIM/CIM models or 3D design drawings) into the LRTK app and display them on screen to overlay them on the actual site view. This enables direct comparison of design models and real-world conditions in structure construction, allowing verification on the spot that formwork and rebar positions match the drawings. For roadworks, AR can display the finished appearance so you can check whether paving thickness or curb lines match the plan. In the housing sector, such as detached house sites, projecting the 3D model of the completed building or exterior onto the lot helps with client consultations and shared understanding of the finished image. Additionally, if the locations of buried underground utilities (e.g., pipes) are scanned and recorded with LRTK in advance, that underground position can be visualized with AR during future excavations to reduce the risk of accidentally damaging utilities.

• Coordinate navigation (stakeout guidance): LRTK includes a function that navigates the user to any target coordinate. The app displays arrows and distance information toward pre-set coordinates on the smartphone screen—simply follow the cues to reach the target. This makes stakeout and setting reference points easy even without specialist surveying knowledge. For example, when placing foundation stakes at locations specified in drawings, the coordinate navigation feature lets you mark the position with centimeter-level accuracy. It’s also effective for finding boundary markers or existing survey stakes that are covered by vegetation or snow. Because one person can reach the target point with a smartphone in hand, it is suitable for narrow or steep sites and reduces the need for multi-person equipment handling. Coordinate navigation is useful not only for as-built inspections but also as a guide during routine inspections and maintenance tasks.

• As-built management (detecting deviations from design): By overlaying point cloud data acquired with LRTK onto design data, as-built management can be made more efficient. You can intuitively confirm whether the current shape matches the design with color-coded displays and quantify quality during construction. For example, comparing uploaded point clouds on the LRTK cloud with design surface data can produce a heat map where areas matching the design in height/slope appear green, areas exceeding the design appear red, and areas below the design appear blue. This instantly shows where additional work or cutting is needed. Because the difference in earthwork volume between current conditions and design is calculated automatically, on-site decisions such as "how many cubic meters of soil need to be delivered" or "how much must be cut to meet the design surface" can be made immediately. For example, in slope construction or revetment works, measurements required by as-built management procedures can be obtained from LRTK-scanned point clouds to generate cross-sections and volume calculations useful for preparing inspection documents. As-built verification that used to rely on craftsmen’s intuition and manual methods can now be performed objectively and quickly based on data, offering major benefits for quality assurance and inspection responsiveness.

• Cloud integration and data sharing: Coordinate data, point clouds, photos, and other data acquired with LRTK can be uploaded to the cloud on site and accessed from the office or remote locations immediately. Data can be managed on a dedicated cloud service and viewed from a web browser as 2D drawings or 3D point clouds, with the ability to measure distances, areas, and volumes. Without expensive installed software, anyone with an internet connection can work with on-site 3D data. By issuing a shared link from the cloud, you can easily share data with subcontractors or clients who do not have a license. Recipients don’t need a high-performance PC or a dedicated viewer—just opening the shared link allows them to view 3D models and point clouds. This enables stakeholders to grasp progress and as-built conditions without visiting the site, smoothing communication. For example, a remote site manager or designer can review point cloud models on the cloud during a meeting and issue immediate additional instructions. In disaster recovery situations, quickly sharing scanned data of affected sites via the cloud allows municipal headquarters and experts to assess damage from the office and rapidly consider countermeasures.

Improved Efficiency and DX Effects from LRTK Adoption

As described above, using LRTK dramatically improves the efficiency of site surveying and construction management. Tasks such as as-built surveying and earthwork calculations that previously took days can now be completed on-site and shared immediately, speeding up decision-making. There is less need to arrange specialist surveyors or halt equipment, improving construction productivity. Allowing one person to handle tasks reduces labor costs and staffing needs, enabling efficient operations where limited personnel can manage multiple sites.

Data-driven construction is more repeatable than analog work that relies on "instinct and experience," making it easier to ensure consistent quality regardless of who performs the work. This is a major DX benefit that reduces dependency on individuals and raises overall organizational capability. As construction records accumulate in the cloud, they become digital assets that support analysis of past cases and planning for the future. For example, storing point cloud data makes future maintenance comparisons with current conditions easier, extending benefits into the post-construction lifecycle.

Above all, advancing on-site DX helps address long-standing industry issues of safety and work styles. Remote surveying of dangerous slopes and reducing heavy labor such as layout stake installation can both reduce worker burden and ensure safety. Paperless operations and improved data sharing reduce reporting time and communication errors, making construction management itself smarter. Thus, LRTK adoption is not only an operational efficiency improvement but also contributes to workstyle reform and business model transformation in construction.

Conclusion

We have looked at "3D construction" and the LRTK technology that supports its realization—what do you think? 3D technologies that were once limited to large-scale sites or specialists have become much more accessible with the advent of LRTK. The ease of performing high-precision, lightweight surveying with a single smartphone is a strong ally for sites beginning digital construction. Feedback from sites that have adopted LRTK includes comments like "even newcomers could take surveys right away" and "we can check as-built conditions daily, which gives a sense of security," making it a well-received entry point for on-site DX.

LRTK’s small, lightweight, and easy-to-use design allows it to be incorporated into existing construction workflows without difficulty, lowering barriers to on-site adoption. No special equipment preparation or complicated settings are required—just take it out when needed and measure or record. This ease and immediacy not only link directly to productivity gains but also help reduce resistance among site staff to DX. If your company is considering DX to address labor shortages, improve efficiency, or enhance quality in your projects, why not try [LRTK](https://www.lrtk.lefixea.com/lrtk-phone) on-site once? You are likely to experience a new level of speed and accuracy in construction management. As an accessible on-site DX tool, LRTK is poised to become the new standard in the construction industry. Please try it on your site and confirm its effects for yourselves.