Complete surveying to design verification on a smartphone!? How AR technology is transforming exterior construction sites

In exterior construction (landscaping) sites, it is not uncommon for rework or disputes to arise because work cannot be executed exactly according to the design drawings. A slight deviation from the site boundary can lead to disputes with neighboring properties, and an error in slope can prevent rainwater from draining properly—small mistakes can cause big problems. Why do such mismatches occur? Behind this issue lies a gap in conveying the designer’s intent to the field and difficulties in sharing information at the construction site.

In recent years, AR (Augmented Reality) technology has attracted attention as a trump card to solve these problems. With improvements in smartphone and tablet performance, AR can now be used on-site without special equipment. In fact, tools have emerged that allow surveying and drawing verification with just one smartphone, and they are poised to significantly change exterior construction sites. In this article, we look back at typical design mistakes in exterior work and their causes, explain in detail how a smartphone-centered workflow using AR technology can solve these issues, and discuss the effects of AR-based visual consensus building, its use for client proposals, and its contribution to work-style reforms that allow efficient operation with small teams. At the end of the article, we introduce the convenience of the latest tool that supports this realization, LRTK.

Typical design mistakes and construction troubles in exterior work

On exterior sites, slight measurement errors or differences in recognition can cause discrepancies between the design and the finished work. Typical failure examples include the following:

• Boundary or positional errors leading to disputes: Misplacing fences or walls so that the finished structure protrudes into a neighbor’s property, or a gate position that differs from the drawing and requires rework.

• Problems due to height or slope errors: Insufficient measurement of ground elevation causing errors in paving or drainage slopes. After completion, water may pool or steps may differ from the planned dimensions.

• Design breakdown due to dimensional errors: Misreading dimensions for an approach or garden layout, resulting in parts that don’t fit as drawn. As a result, the design balance collapses and rework becomes necessary.

Most of these mistakes can be prevented by thorough surveying and coordination before construction, but on-site they often occur because workers are pressed for time or overlook detailed instructions on drawings. When multiple contractors are involved, differing interpretations or lack of coordination can also cause discrepancies. Because exterior work is performed outdoors, weather and terrain have a large impact, and workers are frequently required to make prompt on-site judgments. If those decisions deviate from the designer’s intent, the finished result will be affected. In other words, it is crucial to accurately share the design intent with the field and detect deviations early.

Why design intent is hard to convey to the field

So why aren’t the contents and intentions of design drawings adequately conveyed to the site? Two underlying factors are the gap in understanding drawing information and the fragmentation of information transmission.

First, there is the difficulty of visualizing the finished product from drawings. With only 2D plans and elevations, it is not easy for everyone on site to accurately imagine the actual three-dimensional finish. Designers and construction managers can visualize the 3D form in their heads, but some craftsmen and site staff are not comfortable reading drawings. As a result, even if construction is carried out according to the dimensions on the drawing, the finish may still deviate subtly from the designer’s intended image when adjusted on site.

Next, there is the problem of information being transmitted in fragments. Detailed specifications or changes decided during the design stage sometimes are not fully shared with the field before construction proceeds. Exterior work often involves multiple disciplines—landscaping, civil engineering, electrical work—so drawings and instruction documents can be numerous. For example, if the plan and section drawings, meeting notes with the client, and emailed instructions are not centralized on site, you may end up executing work with only partial information at hand. Such omissions and confusion in information lead to discrepancies with the design intent.

Furthermore, inadequate communication between designers and contractors should not be overlooked. Paper drawings and verbal explanations alone cannot always convey subtle nuances or the designer’s intended “look and feel.” Consequently, aspects not written on the design drawing are left to on-site judgment, and if that judgment differs from the designer’s expectation, mistakes and design inconsistencies can occur.

In this way, there were limits to understanding and conveying drawing information, creating an invisible wall between design and the field. However, AR technology can remove that wall and make it possible for designers, contractors, and clients to share the same image of the finished product.

Effects of AR-driven visual consensus building

AR technology can make a finished image that is hard to convey on drawings visible “on the spot.” Imagine looking through a smartphone or tablet camera and seeing a CG overlay of the completed exterior on an unfinished site. Because you can visually perceive the finished product as if it were right there, all stakeholders can intuitively share the design image.

There are various effects of AR-based visual consensus. First, it enables sharing the design intent without mismatch. Clients can check the appearance of a gate or terrace simply by pointing a smartphone at their yard, without needing printed perspective drawings or physical models. Construction personnel can also grasp, in three dimensions on site, how the design will look from a particular angle and how it balances with the building. When everyone is looking at the same thing and discussing it, misunderstandings like “it looked different from what I expected” can be resolved in advance.

AR also contributes to faster decision-making. For example, when a client asks during a meeting, “How would it look if we raised the fence height a bit?”, you can instantly adjust the height in AR and show the result. Because you can confirm changes together on the spot without redrawing plans, plan revisions are agreed upon more quickly. This improves client satisfaction and reduces the risk of major rework later for the construction side.

Moreover, AR is effective for improving understanding among site staff. Even inexperienced staff can understand at a glance “what and how to build” when they see the finished image in AR. You don’t need long verbal or drawing-based explanations; sharing AR visuals makes it easy for the whole team to grasp the key construction points intuitively. In this way, AR visualizes the design and aligns everyone’s perspective, creating an environment that prevents mistakes and discrepancies.

Workflow for AR display, surveying, point cloud capture, and position verification using a smartphone

How exactly does the workflow at exterior sites change with AR adoption? Here we follow a series of steps in which surveying through AR-based design verification can be completed using a smartphone.

• High-precision on-site positioning and baseline setup: First, accurately measure baseline positions on site using a smartphone. Tasks that previously required total stations or levels for stakeout and leveling can now be performed by obtaining centimeter-level coordinates of the current location via a high-precision GNSS receiver connected to the smartphone or by matching known control points. This links the drawing’s coordinate system to real space and completes the spatial baseline alignment that underpins AR display in a short time.

• Overlaying design data via AR: Next, load exterior design data into an AR app on a smartphone or tablet. Prepared 3D models or plan data are displayed at full scale over the camera feed. For example, a CG model of the planned wood deck or carport appears on a vacant yard and integrates with the real scene. With high-precision alignment, the outlines and placements of structures are projected on site as in the drawing, effectively performing a “virtual stakeout.”

• On-site measurement and point cloud scanning: While confirming the AR display, perform any additional local measurements or scans as needed. Using the smartphone camera or built-in LiDAR, you can simply sweep the surroundings to acquire 3D point cloud data of terrain and structures. For example, scan existing trees or elevation differences to create a digital terrain model and check for interference with the design model. You can also measure, on the AR screen, "how far is it from the building to the wall" or "whether the CG placement aligns with the real peg positions." These data acquisitions previously required specialized equipment and complex procedures, but being able to perform them intuitively with only a smartphone is revolutionary.

• Confirming design positions and marking: Compare the AR-projected design model with actual site conditions to finalize construction positions. For example, check whether temporarily placed blocks or spray markings on the ground align with the design lines shown in AR. If there is any deviation, you can immediately correct and re-stake positions on site. If it matches perfectly, it is evidence that AR-based positioning is accurate, allowing you to proceed with construction with confidence. Additionally, following AR-displayed guides for stake driving or marking enables less experienced workers to place structures at the design-specified positions. In short, the smartphone screen effectively functions as both surveying instrument and stakeout drawing.

• Data storage and sharing: After completing the series of positioning and AR verification tasks, save and share the measurement data and site photos via the cloud. If acquired coordinates, point clouds, and images documenting the AR verification are automatically uploaded to the cloud on the spot, the effort of returning to the office to cross-check drawings and prepare reports is reduced. Real-time sharing between site, office, and client speeds up decision-making and approval processes.

Through this workflow, surveying, design verification, and record-keeping can be completed with a single smartphone. The key point is the ability to perform what used to be separate tasks—"surveying" and "drawing verification"—in parallel. You can measure while verifying designs on site and record the data immediately, eliminating the time spent “taking it back to the office to stare at drawings and hunt for errors.”

Preventing construction errors by on-site design checks and as-built comparisons

The AR-based methods described above also have a tremendous effect on quality assurance during and after construction. In particular, the ability to immediately compare the design and the as-built condition on site leads to early detection and correction of construction errors.

Traditionally, problems were often not discovered until after completion, when as-built measurements with a total station or tape measure were compared with the drawings back at the office. If concrete had already hardened or heavy machinery had been removed during that interval, correcting any discovered mistake could incur significant cost and effort. Using AR, you can intuitively check on site whether construction is being executed according to the design, preventing mistakes before they happen.

For example, consider confirming formwork positions with AR before concrete placement. Display the design shape of the foundation concrete on the smartphone AR screen and overlay it on the on-site formwork. If the formwork’s position or dimensions deviate from the design model, the discrepancy will be clearly visible on the screen. Prompt corrective instructions can fix the issue before pouring concrete, preventing critical rework. Likewise, when checking the height and straightness of a stacked block wall, display the design reference lines and height standards in AR to detect deviations from the actual structure on the spot. Even a few centimeters of tilt or sag—easily missed when relying on a craftsman’s intuition—can be amplified and visualized through the camera, so small errors that would otherwise be overlooked are made visible.

More advanced uses include visualizing errors by comparing point cloud data with design data. You can scan the finished structure with the smartphone’s LiDAR, have the cloud compute differences between the point cloud and the 3D design model, generate a color-coded heatmap of deviations, and then import that heatmap back into AR. Overlaid on the real structure, this reveals intuitively which parts are higher or lower than the design—for example, coloring areas 5 cm higher in red. The heatmap AR that makes deviations obvious helps quickly identify areas needing repair and dramatically improves the PDCA cycle of quality inspections.

If on-site design checks using AR become routine, variability in construction quality will decrease significantly, and a system to nip errors in the bud at the field will be established. Construction managers are freed from the anxiety of having to "check later against the drawings," and can proceed with work while ensuring quality in real time.

Application to client proposals and progress explanations

AR technology is not only powerful for contractor-side management and verification—it is also an excellent tool for proposals and explanations to clients. In exterior construction, sharing the final image with clients is key to winning contracts and improving satisfaction, and AR can make this communication dramatically smoother.

In proposal-stage use, bring a smartphone or tablet to the client’s house before construction and show the planned exterior design overlaid on their yard or entrance. Because CG models of carports, decks, planting, and lighting can be placed in real space, clients can experience a realistic view of how those elements will look on their own property. This not only relieves anxiety about “what if the finished product is different,” but also elicits specific requests and feedback on the spot—such as "this tree is taller than I thought; let's change it to a small tree." Being able to convey texture and depth that catalogs and drawings alone cannot makes aligning client expectations much easier.

AR is also effective for explaining construction progress. When reporting progress to clients at a partly completed site, you can show, via the smartphone screen, the fully planned exterior even if only the skeleton is built. Statements like "a fence will be installed here later" or "this empty area will be sodded" are immediately understood when the finished image is overlaid in AR. Clients can imagine the final result while waiting for completion and feel assured about progress; sudden on-site changes can also be explained visually for quicker understanding.

Additionally, AR allows quick responses to client requests for design changes. For example, if during construction a client says, "I want to expand this flower bed," redesigning would normally take time. But if you adjust size and placement in the AR system and show the client the revised plan on the spot, they can confirm immediately. If they approve, you achieve quick consensus and minimize rework. In this way, AR-enhanced proposals and explanations contribute to building trust with clients. If clients feel the contractor provided thorough explanations throughout, satisfaction after handover and word-of-mouth recommendations are likely to improve.

Contribution to work-style reform and small-team operations for exterior contractors

AR technology and smartphone utilization not only transform on-site work but also contribute to work-style reforms for exterior contractors. With labor shortages and an aging workforce, these technologies are key to achieving high-quality construction efficiently with limited personnel.

First is the prevention of skill centralization. Tasks that relied on the veteran’s intuition and experience—such as surveying and stakeout—can be performed accurately by juniors with AR and smartphones. Visual guidance reduces the number of "things only a veteran can sense," allowing anyone on the team to achieve a consistent level of accuracy. This prevents work from concentrating on particular skilled individuals and promotes sharing knowledge and know-how. In training and handovers, AR-based hands-on experiences accelerate skill acquisition compared to verbal instruction alone.

Next is labor reduction and efficiency. With single-person smartphone surveying, tasks that used to require two-person teams for total station measurements can be done by one person. One staff member carrying a smartphone equipped with LRTK can walk the site, measure required points, and record data while others attend to different tasks. By leveraging these technologies, small contractors can manage multiple sites concurrently with fewer people. Shortened times for surveying, drawing checks, and recording increase the daily workload capacity, contributing to reduced overtime and better work–life balance.

The benefits also extend to responsiveness and information sharing. Previously, unexpected on-site issues often required returning to the office for redesign or re-evaluation. But with a cloud-connected AR system, the site situation can be shared as-is and the office can immediately provide advice or revised designs. Remote supervisors or designers can discuss the site while viewing on-site AR visuals and survey data in real time, minimizing downtime caused by waiting for decisions. This capability is a major support for small-team operations.

Finally, using AR and smartphones can help make the work itself more attractive. Sites that leverage cutting-edge technology appeal to younger workers and aid recruitment. Reducing physical labor and improving productivity raise employee satisfaction. Digital technology can help dispel the industry’s reputation for being "tough, dangerous, and time-consuming," contributing to its overall improvement.

Convenience of simple surveying and AR display functions with LRTK

As we have seen, the combination of smartphones and AR technology brings various benefits to exterior sites. One of the solutions supporting this realization is our company’s “LRTK”. LRTK is a groundbreaking system that transforms a smartphone into a centimeter-accurate surveying instrument by attaching a palm-sized high-precision GNSS receiver and using real-time satellite positioning corrections (RTK). This allows smartphone GPS, which previously had meter-level errors, to determine positions with centimeter-level accuracy. No special setup is required—simply attach the LRTK device to a smartphone, launch the dedicated app, and anyone can immediately use high-precision positioning and AR display with ease.

By introducing LRTK, you can perform the entire workflow—from surveying and point cloud measurement to position guidance and AR projection of design data—using only a smartphone. For example, by attaching an LRTK receiver to an iPhone or Android device and walking the site, you can complete coordinate acquisition for necessary points and 3D scanning of terrain. The acquired data is stored in the cloud in real time, enabling instant information sharing with office staff. Of course, if you load design drawings or 3D models into the app, you can accurately overlay them on site in AR mode. LRTK’s centimeter-level positioning delivers stable AR projection without misalignment, enabling construction management where "you don’t have to imagine it in your head—just look and you’ll understand."

Despite these advanced functions, LRTK balances ease of use and low cost from a field perspective. The device itself is lightweight and compact with a built-in battery, so it can be carried like a handheld GPS or attached to a helmet without burden. Its initial cost is significantly lower than traditional surveying equipment, making it accessible for small and medium exterior contractors. The smartphone app features an intuitive UI so site staff without specialized knowledge can master it after a short training. LRTK is truly a tool that enables "anyone to easily perform high-precision surveying," and it is a next-generation construction support system that complies with ministry-driven initiatives like i-Construction.

AR technology and smartphone surveying are accelerating toward becoming the new standard in exterior construction. By using LRTK, even small teams can efficiently handle everything from surveying to as-built management, achieving both quality and productivity. If you are thinking about transforming your site with smartphones and AR, please consider trying out LRTK. Embrace cutting-edge digital technology and take your exterior construction work to the next stage.