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 make i-Construction successful. We explain concrete on-site DX measures, from the 3D construction cycle that starts with surveying DX (digital transformation), RTK surveying and AR that a single person can perform, cloud-based site-office synchronization, inspection efficiency through automatic report generation, to the use of simple tools anyone can use. By addressing each of these points, you can realize a productivity revolution on construction sites and lead i-Construction 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 is an initiative to fully utilize ICT (information and communication technology) across all processes — investigation/surveying, design, construction, inspection, and maintenance — aiming to improve the efficiency of the entire construction production system and reform workstyles. Measures include digitizing sites with drone photogrammetry and 3D laser scanners, and introducing machine guidance (automatic control of construction equipment) and BIM/CIM (design and construction using 3D models).

From fiscal 2023, the principle of applying 3D models to public works (making BIM/CIM mandatory) began, ushering in an era where clients and contractors share three-dimensional data to carry out work. In addition, the construction industry faces serious labor shortages and the need to respond to overtime regulations in 2024 (the so-called "2024 problem"), so it is necessary to operate sites efficiently with limited personnel. Against this backdrop, the importance of i-Construction, which digitizes entire sites to reduce labor, has increased significantly.

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 to i-Construction success is to start by DX (digitizing) the surveying process. Traditional surveying used total stations and levels to measure heights and positions at key points manually and create plan and long/ cross-section drawings. However, this method is limited by the number of points that can be acquired and cannot fully capture fine details of the entire terrain. Attention is therefore focused on surveying DX using drone photogrammetry and 3D laser scanning. Using these digital surveying technologies, you can acquire enormous 3D survey data (point clouds) numbering in the millions in a short time, and record the site’s current state as a digital twin.

Using three-dimensional as-built data makes it easier to visualize the finished shape from the planning stage before construction. For example, overlaying acquired point cloud data with design CAD data or BIM models lets you intuitively confirm discrepancies between the plan and the actual terrain. During construction, machine operators can work with reference to 3D models, moving away from construction based on intuition and experience and enabling a 3D construction cycle (a system that consistently runs surveying → design → construction → inspection with 3D data). After construction, the completed terrain or structure can be measured again in 3D and compared with the design data to check for as-built errors. In this way, digitizing the initial survey to obtain accurate 3D as-built data lays the foundation for streamlining and improving quality across all subsequent processes.

Point: Introducing surveying DX yields high-accuracy data that covers the entire site, allowing rapid response to re-measurements or design changes. If current point clouds are shared in the cloud with stakeholders, the terrain and dimensions can be checked remotely, dramatically speeding up decision-making. Start by building the foundation for i-Construction with digital surveying using drones, 3D scanners, or smartphone LiDAR sensors.

Success Point 2: Solo Surveying and AR Use with RTK and Smartphones

The second point is to reduce labor and make surveying more intuitive by using RTK, a high-precision GNSS technology, together with smartphones. RTK (real-time kinematic) is a technology that uses two GNSS receivers — a base station and a rover — to correct error information and determine positions with centimeter-level accuracy. Conventional GPS has errors on the order of several meters, but with RTK you can position with a horizontal accuracy of about 2-3 cm (0.8-1.2 in). This enables surveying to be performed by a single operator carrying an RTK-GNSS receiver in situations that previously required two-person optical surveying with a total station (one observer and one target placer). Because RTK can position even where visibility is poor due to obstructions, measurements in mountainous areas or points behind structures can be done efficiently.

Combining RTK with a smartphone makes surveying dramatically easier. Attaching a compact RTK receiver to a smartphone and using a dedicated app turns the smartphone into a high-precision surveying instrument without specialized equipment. In addition, using AR (augmented reality) technology with the smartphone camera allows design drawings and measured point data to be overlaid on the live view of the site. For example, you can visualize design reference lines or structure locations on the actual ground through the smartphone screen, or project previously measured points as virtual markers into the real space. This allows you to “see, measure, and verify” measured data on site immediately, greatly reducing the need to carry paper drawings back and forth.

The benefits of RTK×smartphone surveying go beyond productivity. The intuitive operation of smartphone apps makes surveying tasks that previously required skill accessible to young or inexperienced workers. You can measure simply by pointing the smartphone at the desired location and pressing a button, or confirm the same recorded point effortlessly because previously recorded points appear on the screen, enabling anyone to measure by following the guide. The government has recognized the benefits of such labor-saving technologies and provides subsidies for high-precision RTK surveying equipment as devices that contribute to “shorter, more efficient surveying” and “productivity improvement through one-person operations.” Establishing an environment where one person can easily perform high-precision surveying is a major asset in promoting i-Construction.

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

The third point is to synchronize site and office information in real time through cloud-based data integration. Digitized surveying data and drawing data realize their value when stored and shared in the cloud. For example, if point clouds, coordinate values of survey results, and photos obtained 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 by USB or paper, keeping the site and office constantly updated with the latest information.

A major advantage of cloud linkage is that remote support and instructions become smoother. For example, a veteran survey supervisor in the office can check site survey data uploaded to the cloud and give immediate feedback such as “please measure this point additionally.” The field staff then perform the additional measurements and share the results on the cloud, establishing a work cycle in which the office and site operate as one. This enables efficient allocation of limited specialists across multiple sites and enhances responsiveness amid labor shortages.

Also important is that centralized cloud management makes it easy to maintain the latest version of drawings and survey results. If someone makes a change, it is reflected for everyone immediately, preventing mistakes caused by referring to outdated drawings at the site or in design. Switching from carrying Excel ledgers or paper drawings to accessing the latest information from tablets or smartphones reduces unnecessary travel and transmission time and decreases information transfer errors. Data integration and cloud use form an indispensable foundation that supports the speed and accuracy required under i-Construction.

Success Point 4: Streamline Inspections with Automatic Reports and As-built Management

The fourth point is to digitize as-built management after construction and streamline inspection tasks by automating report creation. As-built management is the process of measuring and recording whether the constructed structures and ground have the shapes and dimensions specified in the design and proving this to the client. In public works, it is necessary to measure and report as-builts at specified locations according to the prescribed accuracy standards. Traditionally, this involved manual measurement with tape measures, staffs (level rods), and levels, handwriting results in field notebooks, and transcribing them into Excel in the office to create reports — a time-consuming process. This analog method was time-consuming for checking each point and carried risks of human error such as recording mistakes or forgetting to attach photos.

Under i-Construction, using ICT for as-built management can dramatically improve efficiency. Specifically, methods that measure as-builts in a planar and 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. Point cloud data records the overall shape of structures at high density, allowing detection of slight unevenness or dimensional errors that would have been missed previously. Measurement results are automatically analyzed in the cloud, and if any area deviates beyond tolerance it is pointed out immediately, enabling on-site corrections on the spot. This reduces the risk of failing inspections and having to redo work, allowing smooth handover while ensuring quality.

Notably, digital as-built measurement enables automatic generation of inspection documents. Using a system that links design values and measured values, as-built management tables (report forms) can be created automatically without manual data entry. For example, lists of as-built dimensions formatted to the specified template, cross-sections, and photo ledgers can be output at the touch of a button. Tasks that used to take days to produce inspection documents are greatly compressed, reducing the burden on site supervisors and inspection staff. By introducing automatic reports and digital as-built management, inspection work becomes more efficient and recording accuracy improves, allowing the finishing stages of i-Construction to proceed smoothly.

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

The final point is to create a system that does not rely solely on specialized personnel in site DX. Introducing new technologies and tools will not deliver true benefits if only a few people can use them. Reliance on individuals — for example, only veteran employees knowing how to operate surveying equipment or only certain staff capable of data processing — hinders productivity improvement. Therefore, it is important to disseminate simple tools that anyone can use across the site.

Fortunately, recent ICT construction tools have dramatically improved usability, with smartphone and tablet applications being representative examples. As mentioned earlier, a surveying system that combines a smartphone and RTK can be learned in a short time by young employees thanks to an intuitive UI. Measurements and records are completed simply by following on-screen instructions, overturning the conventional notion that “surveying is a specialist’s job,” and enabling each site worker to perform surveying and as-built checks as needed. If everyone on site can use digital tools, the burden will no longer concentrate on specific personnel, and backup systems in emergencies will be robust.

Easy-to-use tools are also effective from the perspective of technical succession. While advanced artisan skills are difficult to pass on, digitalized surveying and construction management tools make it easy to develop manuals and educational content. Young workers can learn by operating actual equipment under the guidance of seniors, and veterans can delegate parts of the work to tools and concentrate on higher-level decision-making. As a result, individuals can focus on higher value-added tasks, raising the overall productivity of the organization. Introducing simple, user-friendly DX tools is key to eliminating reliance on individuals and strengthening organizational site capabilities.

Conclusion: Smartphone Surveying with LRTK Supports i-Construction Practice

We have explained the five key points for i-Construction success. Implementing the 3D construction cycle that starts with surveying DX, RTK×smartphone surveying and AR that one person can handle, real-time site-office linkage via the cloud, digital as-built management and automated reporting for streamlined inspections, and eliminating reliance on individuals with easy-to-use tools — by steadily putting these into practice, site productivity and quality will dramatically improve.

One solution that makes these initiatives more accessible 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 cloud services, and it is characterized by its ability to realize the points discussed here all in one.

With just a smartphone, high-precision 3D surveying becomes possible (solo surveying, surveying DX), measurement data is shared in real time via the cloud (site-office synchronization), and location-tagged photos and point cloud data are automatically recorded, making digital as-built management and report creation smooth (inspection efficiency). Above all, its simple UI makes it usable even without specialized knowledge, so anyone on site can operate it (eliminating reliance on individuals with easy tools). With LRTK functioning as a true “one-device-per-person” site DX tool, you can implement these five measures without difficulty.

For companies and personnel looking to promote i-Construction, smartphone surveying with LRTK is an excellent first step. Use cutting-edge surveying DX tools and realize a productivity revolution on your sites.