One-Person Layout: Improving Work Efficiency with AR Guidance and High-Precision Positioning

Layout marking (positioning) is an indispensable task on construction sites that indicates baseline lines and positions on site to ensure structures are built according to design drawings. However, traditionally this layout work required multiple people and considerable effort, relied heavily on the intuition and experience of skilled workers, and if mistakes occurred they could affect the entire project. If this layout could be performed accurately and quickly by a single person, productivity could be greatly improved even on sites suffering from labor shortages.

This article introduces how to efficiently perform layout marking alone by leveraging the latest technologies: high-precision positioning (RTK-GNSS) and AR (augmented reality) guidance. From the challenges of traditional methods, the mechanism of high-precision positioning, the role of AR guidance that enables one-person operation, concrete on-site use scenarios, to the effects on standardization, labor reduction, and error reduction brought by these technologies, we explain everything from the perspective of field practitioners.

The importance of layout marking and traditional challenges

In building and civil engineering work, layout marking means the process of reflecting the positions and shapes of buildings and structures shown on design drawings onto the actual site, displaying baseline lines and points that serve as references. Marks made by layout—such as lines indicating the edge of foundations, centerlines for columns and beams, and reference levels for finishing heights—serve directly as construction guides. Naturally, the accuracy of the layout dictates construction quality, and slight deviations can lead to rework in later stages or distortion of the whole structure. Therefore, experienced surveyors carefully check and perform these tasks, but traditional methods had several problems.

The first problem is the manpower and time required. For example, when setting out a building’s position, a surveyor extracts offset dimensions from drawings and uses measuring tapes or total stations to mark the site. At this time, at least two people are required: one to operate the equipment and another to hold a staff (level rod) or prism at a distant point. In some cases, additional assistants are needed to mark layout points, making it a 2–3 person operation. Procedures such as mounting tripods and repeatedly walking back and forth to verify positions are cumbersome, and even setting out a single point takes effort. When there are many survey points, it is not uncommon for the work to take an entire day.

The second problem is dependence on skilled techniques and the risk of human error. Layout involves reading baseline dimensions from drawings, measuring on site, and drawing lines—processes that rely heavily on human hands and eyes. Inexperienced workers are prone to misreading numbers or measuring incorrectly. Even a small misread can shift baseline lines and cause construction errors. In practice, many tasks depended on veterans’ intuition and experience, making the work highly person-dependent. Also, simply marking layout points on site does not allow thorough verification against drawings at that time, so it is possible to discover later—after comparing with drawings—that the positions were wrong, causing rework. Under traditional methods, a single mistake could lead to a large loss, creating reliability issues in quality control.

The third problem is chronic labor shortages and declining work efficiency. The construction industry faces aging skilled workers and a lack of young personnel, making it hard to secure people capable of layout tasks. Performing layout that requires multiple workers with limited personnel is burdensome and constrains the overall site schedule. For example, when the surveyor is assigned to multiple sites, work can be temporarily suspended while waiting for “layout.” With the demand for greater efficiency, traditional layout methods have significant room for improvement in terms of manpower and time.

Mechanism of high-precision positioning (RTK-GNSS) that enables one-person work

The key to enabling a single person to perform layout is technology that measures positions accurately. Traditional GPS has errors of several meters, making it unusable for construction surveying. However, using the increasingly common RTK-GNSS (Real-Time Kinematic satellite positioning) technology, high-precision positioning with errors on the order of a few centimeters (cm level accuracy (half-inch accuracy)) is possible. In RTK-GNSS, both a reference station (base station) installed at a known position and a mobile unit (rover) receiving GNSS satellite signals correct the rover’s position in real time based on error information captured by the reference station. As a result, the current position can be determined with an accuracy of approximately 2-3 cm (0.8-1.2 in) horizontally and about 3-4 cm (1.2-1.6 in) vertically, delivering positioning performance comparable to traditional surveying instruments.

By using this RTK technology, layout work can be completed by one person. If a worker carrying a receiver can measure their standing position with high precision, they can stand at the coordinates from the drawing on site and indicate points directly. For example, as long as the coordinates for column positions or structural reference points are known, a single worker can move to those coordinates and mark the specified points, completing the layout. There is no need to set tripods and measure angles each time like with a total station, or to call back and forth with a partner to fine-tune positions. Even when measuring multiple distant points across a large site, there is no need to repeatedly set up equipment; the worker can simply walk around with the mobile unit in hand, enabling dramatic efficiency improvements in surveying and layout processes. Also, as long as radio signals reach, positioning is possible even at points shaded by obstacles, making layout easier in locations that were previously hard to sight.

Achieving high-precision positioning requires an environment where GNSS signals can be received well and a communication means to obtain correction information from the reference station. In Japan, network RTK services using electronic reference points and the centimeter-level positioning augmentation service (CLAS) by the Quasi-Zenith Satellite “Michibiki” are making it possible to obtain stable correction information even in mountainous or communication-outage areas. By utilizing these services, high-precision positioning based on public coordinate systems can be achieved without installing a dedicated base station on site. In addition, ultra-compact RTK-GNSS receivers that can be attached to smartphones have recently appeared, enabling centimeter-level positioning to be performed with the feel of carrying a smartphone (centimeter-level positioning (cm level accuracy (half-inch accuracy))). With these advances, surveying for layout that previously required specialized equipment and skilled operators is becoming a measuring technology that anyone can handle easily.

The role of AR guidance and its impact on work efficiency

Even if high-precision positioning allows each person to obtain accurate coordinates, site work will not become sufficiently efficient unless there is a system to intuitively grasp the location those coordinates indicate. This is where the power of AR (augmented reality) guidance comes in. Through a smartphone or tablet camera, the site viewed on the screen has design lines and pile locations overlaid as virtual objects—this is the idea of AR-guided work. For example, if a point corresponds to a building corner on the design, a virtual pin or glowing marker will appear at that point on the phone screen. The worker simply moves their position or orientation slightly until the AR marker on the screen aligns with the actual ground position, then marks that spot. Tasks that used to rely on intuition—comparing paper drawings to the ground and guessing “this should be about here…”—become tasks where the worker can confirm positions just by looking at the screen.

AR guidance enables significant efficiency gains and error reduction in layout work. Because positions can be matched visually and intuitively, rework due to misreading or measuring errors decreases. Even beginners can reliably perform layout by following instructions on the smartphone screen, without advanced surveying knowledge. AR apps track and display positions in real time, so a single worker can proceed to successive target points without getting lost. Steps that previously required two people to call out “a little more to the left” or “mark here” can be carried out by following on-screen guides. In addition, since the design lines and virtual stakes shown in AR are always based on accurate coordinates, work can proceed without stringing physical lines or chalk lines. If needed, the worker can leave marks at key points on the ground and continue the work with lines displayed on the screen. By using AR guidance in this way, one-person operations can achieve fast and reliable layout. Furthermore, because design information and site status can be compared on the screen at all times, misplacements can be detected and corrected immediately on site, preventing rework.

Actual on-site use scenarios

Now, let’s look at concrete scenarios showing how site work changes when AR guidance and high-precision positioning are combined.

• Pile driving work: For layout of baseline lines or pile-driving positions, craftsmen traditionally walked the site repeatedly and coordinated with surveyors to mark positions using wooden stakes or chalk. With RTK×AR technology, pointing a device at the location corresponding to the pile position on the design makes a virtual pile or marker appear on the screen. The operator can drive the actual pile using that as a guide, and even where physical piles cannot be driven—such as on bedrock or steep slopes—the exact position can be indicated. When there are multiple pile points, the AR display shows the next design position as the worker moves, allowing one person to sequentially indicate pile locations.

• Foundation layout: AR guidance is also effective for marking the building outline and foundation positions. Normally, you would measure dimensions from drawings, mark the ground with chalk lines, or string lines to indicate the foundation shape, but this method carries the risk of measurement mistakes causing misalignment. By loading the building’s design data (plan lines) into an AR-capable device, the foundation outline is virtually displayed along the ground simply by pointing the camera. The worker then marks key points along that line to complete accurate positioning. A single person can draw an accurate building perimeter, preventing rework due to foundation misplacement and enabling smooth handover to subsequent construction stages.

• Boundary setting: Before starting work, it is necessary to clearly indicate the site boundary, but if existing boundary stakes are unclear, surveying takes time. By importing boundary point coordinates obtained with RTK-GNSS into an AR app, the cadastral boundary can be virtually displayed on site. The boundary appears on the smartphone screen as a glowing line, making it immediately clear “where the site begins and ends.” The worker can mark required points along the on-screen line, greatly reducing the effort of stringing ropes. When confirming boundary positions with surrounding stakeholders, the overlaid line on the actual scenery reduces misalignment in recognition and facilitates quicker agreement.

Contribution to standardization, labor reduction, and error reduction in layout

By incorporating high-precision positioning and AR guidance, the following effects can be expected for layout work.

• Standardization: Because layout is performed according to digital design data and positioning systems, anyone can follow the same procedures, enabling uniformity in work quality. Results are less likely to vary between veterans and newcomers, transforming a person-dependent task into a highly reproducible process. Reliance on the ability to read paper drawings or on experience is reduced, decreasing variability across sites and maintaining stable accuracy overall. Additionally, layout point coordinates and records remain as data, making it easy for third parties to verify or for different workers to take over. This promotes standardization and information sharing, improving construction management reliability.

• Labor reduction: If one person can complete layout, the assistants previously required can be reassigned to other tasks. In extreme cases, one person with one smartphone surveying device can independently set out positions, eliminating wasted time spent “waiting for someone to be available.” On sites where survey scheduling caused queues, layout can be done immediately when needed, enhancing overall work efficiency. There are reports where a layout that previously took three people 20 minutes was completed by one person in 10 minutes; one-person operation has led to significant reductions in labor hours, shorter schedules, and cost savings. Labor reduction contributes not only to lowering personnel costs but also to creating a flexible site organization that operates with fewer people.

• Error reduction: With fewer human interventions in reading measurements or marking points, human error decreases. AR allows immediate detection of deviations from the design on site, preventing rework and redo. Traditionally, layout marks made on site were checked against drawings back at the office, and if discrepancies were found, the site had to be revisited for corrections—an inefficient cycle. AR guidance greatly increases the likelihood of getting it right on the first attempt. Fewer errors lead to improved quality and shorter schedules, and they significantly reduce site stress and waste.

Recommendation for simple surveying with LRTK

Finally, as a concrete solution enabling the one-person surveying and layout described above, we introduce LRTK. LRTK is an all-in-one surveying system consisting of a compact RTK-GNSS receiver that can be attached to a smartphone and a dedicated app. By simply attaching the receiver—weighing only about 125 g—to a smartphone, you can perform centimeter-level positioning (cm level accuracy (half-inch accuracy)), record points, carry out layout (positioning), and even capture point clouds and overlay completed images in AR, covering almost all surveying and measurement functions needed on site. No specialized operations are required: tap a button on the smartphone screen at the point you want to measure to immediately record coordinates, and follow the displayed AR guide to move directly to pile-driving or as-built verification points. Measurement data can be shared with stakeholders via the cloud, enabling smooth coordination between site and office.

LRTK’s concept is “anyone, anywhere, measure immediately,” aiming to make site surveying and layout a simple extension of daily tasks. For example, not only veteran technicians but also young site managers and heavy equipment operators themselves can take a device from their pocket, measure required dimensions, or check baseline lines on the spot. On sites that introduced LRTK, some reported that tasks that previously stopped while waiting for the surveying team can now be measured on the spot by a single person, leading to significant time savings. By utilizing such simple surveying tools that combine high-precision GNSS and AR, traditional layout methods can change, directly improving site productivity and reducing labor. As a new option suited to an era of labor shortages, it is certainly worth considering for introduction at your site.