i-Construction Success: 5 Key Points — From Surveying DX to Construction Management

*In recent years, "i-Construction" has attracted attention in the construction industry as an initiative to digitize on-site processes from surveying to construction management, dramatically improving productivity and efficiency. This article introduces five key points to successfully implement i-Construction. We explain concrete DX measures for the field, from the 3D construction cycle that starts with surveying DX (digital transformation), to single-person RTK surveying and AR utilization, cloud-based site-office synchronization, inspection efficiency through automatic report generation, and the use of simple tools anyone can operate. By addressing each of these points, you can realize a productivity revolution at construction sites and lead your i-Construction efforts to success.*

What is i-Construction? Background of On-site Digitalization

i-Construction is a productivity-revolution project for construction sites promoted by the Ministry of Land, Infrastructure, Transport and Tourism since 2016. It aims to comprehensively apply ICT (information and communication technology) to all processes — survey and measurement, design, construction, inspection, and maintenance — to improve the efficiency of the entire construction production system and reform the way of working. Measures include digitizing sites with drone photogrammetry and 3D laser scanners, and introducing machine guidance (automatic control of construction machinery) and BIM/CIM (design and construction using 3D models).

From fiscal 2023, the principle application of 3D models in public works (making BIM/CIM mandatory) began, ushering in an era where owners and contractors share three-dimensional data to carry out work. Moreover, the construction industry faces serious labor shortages and must respond to overtime regulations in 2024 (the so-called "2024 problem"), making it necessary to run sites efficiently with limited personnel. Against this background, the importance of i-Construction — which digitalizes whole sites to reduce labor — has grown even more.

Now, let’s look concretely at the five success points for practicing i-Construction on site and achieving results.

Success Point 1: Start the 3D Construction Cycle with Surveying DX

The first step toward i-Construction success is to begin by DXing (digitizing) the surveying process. Traditional surveying used total stations and levels to manually measure the height and position of key points on site and create plans and cross-sections. However, this method is limited in the number of points it can acquire and cannot capture fine details of the entire terrain. That is why surveying DX, using drone photogrammetry and 3D laser scanning, is attracting attention. With these digital surveying technologies, you can acquire an enormous amount of 3D survey data (point clouds) numbering in the millions in a short time, recording the site conditions as a digital twin.

Using 3D as-is data makes it easier to visualize the finished form from the planning stage before construction. For example, overlaying acquired point cloud data with design CAD data or a BIM model allows you to intuitively check discrepancies between the plan and the actual terrain. During construction, equipment operators can work with reference to 3D models, enabling a shift away from intuition- and experience-based construction and realizing a 3D construction cycle (a system that runs surveying→design→construction→inspection consistently with 3D data). After construction, the completed terrain or structures can be re-measured in 3D and compared with the design data to check as-built deviations. In this way, digitizing the initial survey to obtain accurate 3D as-is data provides the foundation that streamlines all subsequent processes and improves quality.

Point: By introducing surveying DX, you obtain high-precision data that covers the entire site, enabling quick responses to additional re-measurements or design changes. If the as-is point cloud is shared in the cloud with stakeholders, the terrain and dimensions can be checked remotely, significantly speeding up decision-making. Start by adopting digital surveying using drones, 3D scanners, or smartphone-mounted LiDAR sensors to build the foundation for i-Construction.

Success Point 2: One-Person Surveying and AR with RTK and Smartphones

The second point is to leverage RTK, a high-precision GNSS technology, together with smartphones to reduce labor and make surveying more intuitive. RTK (real-time kinematic) uses two GNSS receivers — a base station and a rover — to correct errors and determine positions with centimeter-level accuracy. While conventional GPS can have meter-level errors, RTK enables positioning with horizontal accuracy on the order of 2–3 cm. This allows surveying tasks that previously required two people (an observer and a target placer) with optical instruments like total stations to be performed by a single worker equipped with an RTK-GNSS receiver. Because positioning is possible even in sites with poor visibility due to obstacles, point measurement in mountainous areas or points behind structures becomes efficient.

Combining RTK with a smartphone makes surveying dramatically easier. By attaching a compact RTK receiver to a smartphone and using a dedicated app, the phone can function as a high-precision surveying instrument without specialized equipment. In addition, using AR (augmented reality) via the smartphone camera makes it possible to overlay design drawings and survey point data on live site images. For example, you can visualize baseline lines or structure positions from design drawings on the actual ground through the smartphone screen, or project pre-measured points as virtual markers into the real world. This enables immediate on-site "see, measure, and verify" workflows, greatly reducing the need to carry paper drawings back and forth across the site.

The effects of RTK×smartphone surveying go beyond productivity. The intuitive operation of smartphone apps makes surveying — which used to require expertise — easier for young or inexperienced staff. Measurements can be taken simply by pointing the phone at the desired location and pressing a button, and previously recorded points can be displayed on the screen so users can confirm the same position without confusion; following the on-screen guides, anyone can measure. The government has also noted the benefits of such labor-saving technologies, and high-precision RTK surveying equipment is eligible for subsidies as devices that contribute to "efficient surveying in a short time" and "productivity improvements by single-person operation." Establishing an environment where a single person can easily perform high-precision surveying will be a major asset in promoting i-Construction.

Success Point 3: Synchronize Site and Office with Data Integration and the Cloud

The third point is to synchronize site and office information in real time through cloud-based data integration. Digitized survey data and drawing files demonstrate their true value when stored and shared in the cloud. For example, if point cloud data, survey coordinate values, and photos collected on site are uploaded to the cloud on the spot, office staff can immediately view and check the data. This eliminates the traditional time lag of waiting for measurements to finish and transferring data via USB or paper, keeping the site and office always shared with the latest information.

Cloud integration also facilitates smooth remote support and instructions. For example, a veteran survey chief in the office can review field survey data uploaded to the cloud and instantly provide feedback like "let’s measure this point additionally." The field staff can perform the additional measurement and share the results back to the cloud, creating an integrated site-office work cycle. This makes it possible to allocate limited specialist personnel efficiently across multiple sites, enhancing the ability to respond despite labor shortages.

Moreover, centralizing data in the cloud makes it easier to manage the latest versions of drawings and survey results, which is an important point. When someone makes a revision, it is immediately reflected for everyone, preventing mistakes caused by referring to outdated drawings at the site or in design. Switching from carrying Excel ledgers or paper drawings to accessing up-to-date information from a tablet or smartphone reduces unnecessary travel and transmission time and decreases information transfer errors. Data integration and cloud utilization form an indispensable foundation to support the speed and accuracy required under i-Construction.

Success Point 4: Streamline Inspections with Automated Reports and As-Built Management

The fourth point is to digitalize as-built management after construction and streamline inspection tasks by automating report creation. As-built management is the process of measuring and recording whether constructed structures and ground conditions conform to the design shape and dimensions, and proving this to the project owner. In public works, it is necessary to measure and report as-built conditions at specified points according to prescribed accuracy controls. The traditional approach relied on tape measures, staffs (leveling rods), and levels to measure manually, with results recorded by hand in field notebooks and later transcribed into Excel in the office to create reports — a time-consuming process. This analog method not only took time for point-by-point checks but also carried the risk of human errors like recording mistakes or forgetting to attach photos.

Under i-Construction, using ICT in as-built management enables dramatic efficiency gains. Specifically, methods that measure as-built conditions in a surface or volumetric manner using 3D scanners or RTK-GNSS and compare the acquired data with design data in dedicated software to determine pass/fail are becoming widespread. With point cloud data, the overall shape of a structure can be densely recorded, enabling detection of slight depressions or dimensional errors that were previously overlooked. Measurement results can be automatically analyzed in the cloud, and if any areas deviate beyond allowable thresholds they are immediately flagged, allowing on-site corrections to be made then and there. As a result, the risk of failing inspection and rework is reduced, enabling smooth handover while ensuring quality.

Notably, such digital as-built measurement enables automatic generation of inspection documents. If measured values are linked to design values in advance, as-built management charts and report forms can be created automatically without manual data entry. For example, you can output lists of as-built dimensions following specified formats, cross-sections, and photo logs at the push of a button. Tasks that used to take days to prepare inspection documents are significantly compressed, reducing the workload on site supervisors and inspection staff. The introduction of automated reports and digital as-built management will both streamline inspection operations and improve record accuracy, allowing the finishing stages of i-Construction to proceed smoothly.

Success Point 5: Eliminate Dependency on Individuals with Easy-to-Use Tools

The final point is to build a system that does not rely entirely on specialized personnel in site DX. Even if new technologies and tools are introduced, their true benefits cannot be realized if only a few people can operate them. Dependency on individuals — where only veteran employees know how to operate surveying equipment or only certain staff can process data — becomes a bottleneck to productivity improvements. What’s important is to permeate the site with simple tools that anyone can use.

Fortunately, recent ICT construction tools have dramatically improved usability, with smartphone and tablet applications as prime examples. As mentioned earlier, a surveying system that combines a smartphone with RTK can be learned quickly by younger staff thanks to its intuitive UI. Following on-screen prompts completes surveying and recording, overturning the conventional notion that surveying is a specialist job and enabling each site worker to perform surveying and as-built verification as needed. If everyone on site can use digital tools, workload will not concentrate on specific individuals, and robust backup arrangements will be in place for emergencies.

Easy-to-use tools are also effective from the perspective of skills transfer. While advanced craftsmanship can be difficult to pass on, digitalized surveying and construction management tools make it easy to create manuals and educational content. Young staff can learn by practicing on real equipment under the guidance of seniors, and veterans can delegate parts of the work to tools, allowing them to focus on higher-level decision-making. As a result, each person can concentrate on higher value-added tasks, raising the organization’s overall productivity. The introduction of simple, user-friendly DX tools is a key to eliminating individual dependency and strengthening organizational site capabilities.

Conclusion: Smartphone Surveying with LRTK Supports i-Construction Practice

Above, we explained five key points for successful i-Construction. The 3D construction cycle starting from surveying DX, RTK×smartphone surveying and AR enabling one-person operations, real-time site-office linkage via the cloud, digitalization of as-built management and automated report creation, and elimination of individual dependency with easy-to-use tools — by steadily implementing these measures, productivity and quality at construction sites can improve dramatically.

One solution that brings these efforts closer to reality is smartphone surveying with LRTK. LRTK is a surveying system composed of a compact RTK-GNSS receiver that can be attached to a smartphone, a dedicated app, and the cloud; it is characterized by its ability to realize the points mentioned here all-in-one.

With just a smartphone, high-precision 3D surveying becomes possible (surveying DX and one-person surveying), and measured data is shared to the cloud in real time (site-office synchronization). Because photos and point cloud data with position information are recorded automatically, digitalization of as-built management and report creation is smooth (inspection efficiency). Above all, the simple UI design makes it usable without specialized knowledge, so anyone on site can operate it (eliminating individual dependency). With LRTK functioning as a true "one device per person" site DX tool, these five measures can be implemented without difficulty.

For companies and personnel seeking to promote i-Construction, smartphone surveying with LRTK is an ideal first step. Utilize cutting-edge surveying DX tools and realize a productivity revolution at your sites.