Site surveying before exterior design can be completed with a smartphone! Accurate and fast on-site measurement with LRTK

When designing exteriors (landscaping and hardscaping), on-site surveying of the lot is an indispensable step. However, conventional surveying has been time-consuming and labor-intensive and required specialized knowledge. If accurate site surveying could be completed using only a smartphone, operational efficiency would improve dramatically. This article introduces how to achieve accurate and rapid on-site measurement using the smartphone-linked high-precision positioning system LRTK. We explain in detail the points that allow exterior contractors to handle everything from surveying to proposals seamlessly in their exterior work.

The importance of site surveying in exterior design

In residential exterior (landscaping and hardscaping) work, it is extremely important to conduct accurate site surveys before construction begins. If the lot boundary is mistaken, it can lead to boundary disputes with neighbors; even a slight positional error can cause fences or walls to protrude into adjacent land or make an approach path not match the plan. To prevent such troubles and rework and to achieve the designed quality, meticulous surveying before starting work is essential.

In exterior planning, understanding elevation differences and slopes on the site is also important. For example, if ground elevations are not measured accurately, it can impair drainage planning or cause the final finish heights to be off. In concrete slab slopes and garden construction, errors of a few centimeters can greatly affect rainwater flow and appearance, so precise elevation measurement and leveling work are required. In this way, site surveying is a highly important process that underpins the quality and smooth progress of exterior work.

Conventional surveying methods and challenges for exterior contractors

Surveying methods traditionally used by exterior and landscaping contractors include total stations (TS), optical levels, and manual work using tape measures, rods (staffs), and spirit levels. Skilled craftsmen can achieve high accuracy with these methods, but there have been the following challenges on site.

• Handwork and time burden: When using a TS, at least two people (instrument operator and prism holder) are required, and surveying can take a full day on large sites or when there are many survey points. Measuring and marking repeatedly with tape and chalk is very time-consuming, and over long distances, tape sag and difficulty keeping a straight line cause subtle cumulative errors. Garden projects with complex curved layouts require detailed measurements and calculations, which are a heavy burden with conventional methods.

• Measurement errors and human error: Manual work is prone to mistakes when people read and record numbers. For example, if the measurement "503 cm" is mistakenly recorded as "508 cm" when writing down tape-measure results, that creates a 5 cm error. Small misreads with a spirit level can also throw off slopes. Points that were painstakingly measured can require remeasurement if stakes or chalk marks are erased by other work. Such human errors and rework can cause project delays and additional costs.

• Constraints from site conditions: In narrow urban lots or sites with many obstructions, TS line-of-sight cannot be secured and the instrument is hard to set up, which is a conventional-method challenge. Inner courtyards surrounded by buildings that cannot be measured directly from control points require placing temporary reference points and indirect measurement, increasing steps and the risk of errors. In such site conditions, conventional methods sometimes struggle to ensure accuracy.

• Outsourcing costs: Even for small exterior jobs, hiring a surveyor for accuracy can cost hundreds of thousands of yen. Handling it in-house requires a large initial investment in expensive surveying equipment and personnel costs, making it hard to justify for surveys that are infrequent. As a result, sufficient surveying has at times been skipped or construction relied on empirical judgment, increasing the risk of later rectification.

How LRTK surveying that can be completed with a smartphone works and how to use it

A new solution that addresses the above challenges is LRTK, which enables centimeter-level surveying easily with a smartphone. LRTK is a high-precision positioning system developed by our company that pairs a pocket-sized receiver with a smartphone. Using real-time kinematic (RTK) methods, it instantly corrects errors in satellite positioning such as GPS, reducing typical positioning errors of several meters to just a few centimeters. For example, with LRTK you can obtain position coordinates with an accuracy of horizontal ±1–2 cm (±0.4–0.8 in) and vertical ±3 cm (±1.2 in), making measurement in the height direction possible where it was previously difficult. Because this high-precision positioning can be handled in real time on a smartphone app, there is no need to repeatedly mark points on the ground for each measurement. Simply connect a dedicated LRTK receiver to your smartphone via Bluetooth and launch the app, and one person can start surveying.

Basic usage of LRTK surveying:

• Equipment preparation: Attach the palm-sized "LRTK Phone" receiver to your smartphone and start the LRTK app. The receiver is a lightweight, battery-powered unit weighing only about 165 g, so complicated equipment setup is unnecessary. It connects wirelessly to the smartphone with no cables, making it easy to carry on site.

• Positioning and point-cloud scanning: While checking coordinates on the app, simply take the smartphone to the point you want to measure and high-precision coordinates for that point are obtained. By using the smartphone camera or LiDAR sensor to scan the surroundings, the app can automatically generate an absolute-coordinate 3D point-cloud dataset. You can record the entire site simply by walking while holding the smartphone, preventing missed measurements.

• Data storage and sharing: Survey data and on-site photos can be uploaded to the cloud immediately from the app. Office PCs can check on-site measurement results in real time, and team data sharing is easy. As described later, this cloud linkage allows the data to be used for client proposals and construction management.

The LRTK app offers an intuitive UI designed so users will not get lost even without specialist knowledge. Complex settings and calculations are automated, allowing staff without survey expertise to start using it right away. Unlike traditional instruments, there is no complicated setup—anyone can achieve high-precision positioning with a smartphone-app feel, which is revolutionary.

Creating 3D models with high-precision RTK positioning and point-cloud scanning

LRTK’s greatest features are its unprecedentedly high positioning accuracy and the ability to create 3D models of the site. The RTK method reduces GPS positioning errors that were several meters down to several centimeters, providing accuracy in exterior site surveying that generally makes error concerns negligible. RTK positioning accuracy is generally said to be about ±2–3 cm (±0.8–1.2 in), giving reliable placement for fine structures such as fences and flowerbeds. Vertical measurements can also be taken with similar accuracy, allowing leveling and elevation measurements previously done separately to be handled in one operation.

Moreover, by using the smartphone’s camera or LiDAR for point-cloud scanning, you can model the site entirely in 3D. With LRTK, simply walking around the site while holding the smartphone captures high-density point-cloud data, recording everything on the lot in three dimensions, from building exteriors to fences, plantings, and window frames. On the acquired point cloud you can later measure elevation differences and distances between any two points, so you won’t have to worry that “we forgot to measure that spot.” Scanning on site achieves zero missed measurements, and required dimensions can be confirmed later in the data. One person can scan every corner, making it possible to efficiently create a detailed as-built model even on sites with labor shortages.

Because the point-cloud data contain geographic coordinates (latitude, longitude, elevation), they can be imported into CAD software and used as an as-measured site model, or cross-sections can be extracted to examine elevation differences. Where previously one had to imagine terrain from 2D site survey drawings, 3D models make terrain and surrounding context intuitive. LRTK point-cloud scanning can therefore be seen as producing a digital asset that goes beyond simple surveying and forms the foundation for design.

Cloud visualization, sharing, and AR display: improving proposal capability to clients

Survey data and point-cloud models acquired with LRTK can be visualized and shared on the cloud immediately. Coordinates and photo location info measured on site are synchronized to the cloud-based "LRTK Web Service" on the spot, allowing colleagues and supervisors in the office to check data in real time. For example, in progress reporting you can instantly share coordinate-backed confirmation such as “the gatepost foundation has been placed according to the drawing,” giving persuasive reporting to remote clients or supervisors. Using the cloud viewer, point clouds can be viewed in a browser without specialized software, and distance, area, and volume measurements can be completed on the web as needed. Since data can be used without high-performance PCs or dedicated software, the barrier to information sharing inside and outside the company is lowered.

LRTK also enhances proposal power through AR (augmented reality) display. If design drawings or 3D completion models are preloaded into the LRTK app, you can project the completed image onto the actual site through the smartphone screen. For example, during an exterior proposal, simply holding up the smartphone lets the client see the planned garden, gate, or wall superimposed on the real site. This allows clients to intuitively experience the finished image that is difficult to convey with drawings alone, greatly increasing persuasive power. Statements like “This is the image of a wall of this height” or “A feature tree will be placed here” can be shown as realistic visuals composited with the real view—an important point of differentiation. Being able to share exterior designs before completion reduces client misunderstanding and improves satisfaction.

Applications for understanding existing conditions: retaining walls, slopes, and existing structures won’t be missed

Point-cloud scanning with LRTK records every detail of the existing condition, making it extremely useful as a tool for current-condition assessment in exterior planning. For example, if an old retaining wall exists on the lot, its position, height, and slope can be accurately derived from the point-cloud model. Inclination and structural soundness assessments that formerly relied on craftsmen’s visual estimates or partial measurements can be analyzed objectively in 3D data. On steep slopes, detailed scanning of ground undulations enables creation of cross-sections needed for earthworks and drainage planning. With centimeter-level data, you can accurately determine where retaining walls are needed and estimate cut-and-fill volumes.

Existing structures on the lot (garden stones, trees, sheds, pole lights, etc.) can also be identified precisely from the point cloud. This allows planning to avoid them or, conversely, to design proposals that make use of existing features. Traditional survey drawings often show only building outlines and lot boundaries, causing small existing items to be overlooked; LRTK’s point-cloud data recreate the site “as-is,” leaving nothing out. This prevents design mistakes such as “we later discovered an existing drainage inlet” or “we didn’t account for overhanging neighbor trees.” Because scan data are stored in the cloud, even if a problem arises during construction you can review the as-built condition later for verification. In this way, LRTK dramatically improves the accuracy and comprehensiveness of site surveys and becomes a powerful tool supporting reliable exterior design.

Differentiate your exterior proposals with LRTK

By introducing smartphone surveying, exterior contractors can differentiate themselves through proposal ability and service quality. First, LRTK prevents delays caused by waiting for surveys, enabling faster and more accurate plan presentation than competitors. For example, site surveys that previously required coordinating a survey team over several days can be completed in a short time by a single staff member using LRTK. You can obtain a same-day 3D as-built model and accurate dimensional information and reflect them in CAD drawings or renderings that day—this speed directly improves client satisfaction and builds a reputation for responsiveness and reliability.

Next, the persuasiveness of proposals themselves improves. As noted above, providing a completion visualization via AR and evidence-backed design explanations based on detailed point-cloud data adds value that was previously unavailable. While competitors may offer impression-based plans, firms using LRTK can support proposals with statements like “we have surveyed the site to this extent” and “we measure to ±2 cm (±0.8 in) accuracy,” giving clients reassurance and demonstrating technical advancement. In the construction industry undergoing DX (digital transformation), offering services that leverage the latest technology is a major strength. LRTK is attracting attention as a solution compatible with *i-Construction* promoted by the Ministry of Land, Infrastructure, Transport and Tourism, and adopting this emerging industry-standard high-precision positioning technology early can enhance corporate image.

Moreover, LRTK-driven efficiency brings cost benefits. By performing surveys in-house rather than outsourcing, you reduce personnel and outsourcing costs and can reallocate time saved from shorter schedules to other tasks. High accuracy reduces rework and additional construction risk, so overall the equipment investment is expected to be offset by cost savings. Thus, introducing LRTK is a key to simultaneous “quality improvement” and “efficiency gains” that enable differentiation.

LRTK application examples (residential exteriors, developed land, narrow urban lots, slopes, etc.)

Smartphone-based LRTK surveying is powerful in a variety of site situations. Here are representative use cases.

• Residential exterior renovations: For single-family home exterior renovations, accurately measuring existing buildings and gardens is important. LRTK can scan everything from building façades to the entire lot in detail, enabling planning that matches existing conditions for gate positions and approach shapes. For example, if the building exterior and window positions are captured in the point cloud, newly installed wood decks or canopy locations can be designed to fit precisely. Avoiding post-completion issues such as doors not opening or overlaps with windows is a major advantage. The acquired point cloud can be shared with the client via the cloud as a “current model of your house” to deepen understanding and confidence in the renovation scope.

• Large-scale land development and exterior works: On reclaimed or residential development sites, wide-area surveying and placement of many structures are required. With LRTK, control-point layout and positioning of equipment that used to require a survey team can be carried out sequentially by a single person. In large subdivisions, a single operator can measure and set positions for streetlight poles, fences, and plantings, preventing construction teams from being held up awaiting surveys. Since an actual-measurement accuracy of around ±3 cm (±1.2 in) can be maintained, even on wide sites fine placement of street furniture can proceed with confidence. LRTK can also quickly scan the entire terrain of sites with large elevation changes, useful for pre-/post-earthwork volume calculations and retaining-wall design. There are reports of large-scale terrain surveying that used to take days being completed in minutes, producing significant schedule reductions.

• Narrow urban lots and complex-shaped sites: LRTK truly shines on lots in densely built urban areas or irregularly shaped sites. RTK positioning can determine location from multiple satellites even without a clear line of sight, making it suitable for narrow sites where total stations are difficult to use. It is especially effective for small or constrained sites and is expected to see increasing use. Curved lot boundaries can be traced accurately on point-cloud data, enabling plans for irregular sites without wasted or forced layouts. For lots facing narrow alleys, there is no need to carry bulky equipment, and measurements can be taken with a smartphone in hand, reducing nuisance to neighbors. LRTK is a reliable ally for urban exterior design that maximizes limited space.

• Sloped and terraced lots: Exterior work on slopes requires measuring slope gradients and designing with elevation differences in mind. LRTK’s 3D measurement can capture slope height information as surfaces, enabling accurate decisions about where to cut and where to fill. For example, for a lot with a 2 m (6.6 ft) height difference, the point-cloud model allows detailed analysis of the step shape and interaction with surrounding areas. When installing retaining walls, required lengths and heights can be derived from the as-found data, reducing design mistakes. Presenting a completion image that includes the steps on the site model also makes it easier to gain client understanding. Even at mountain sites where internet connectivity is unstable, the LRTK receiver can use CLAS signals distributed by Japan’s Quasi-Zenith Satellite System “Michibiki,” maintaining high-precision positioning. Thus, LRTK provides stable surveying for sloped and terraced sites and supports difficult exterior planning.

Seamless in-house workflow from site survey to design, proposal, and construction management

By adopting LRTK, exterior contractors can complete the entire process—site survey, design, proposal, and construction management—in-house. Conducting surveys internally eliminates the need to coordinate schedules with other departments or external parties, allowing design work to begin immediately after site inspection. Point-cloud data can be imported directly into design tools, preventing miscommunication to designers. 3D models created during design can be shared on the LRTK cloud for sales staff to use in client presentations, facilitating smooth internal collaboration.

LRTK is also powerful during construction. Site supervisors and workers using the LRTK app can drive stakes and mark positions (layout) on site according to the design. For complex-shaped pavements and curved flowerbeds, AR display of drawing data can project guide lines onto the ground, enabling construction that matches the design intent. If as-built measurements are uploaded to the cloud during construction, headquarters-based construction managers can check progress and accuracy remotely. For example, information like “the foundation for XX has been placed in the specified position” can be shared immediately with coordinates, streamlining reporting and approval processes with supervisors and clients. If problems are found, quick corrective instructions can be issued based on cloud data, minimizing rework.

Furthermore, LRTK data are useful for aftercare and future renovations. Because all survey data are digitally stored in the cloud, you can always retrieve information such as “where piping was buried” or “the exact position of boundary blocks” after project completion. If additional work is requested years later, existing structure positions can be checked from stored data without re-surveying. In this way, adopting LRTK enables digital-data utilization across investigation → design → proposal → construction → maintenance, greatly enhancing continuity and reproducibility of operations.

Why LRTK’s simple surveying can be used immediately even by first-time users

When hearing “high-precision surveying,” one might think it requires a seasoned surveyor. However, LRTK’s simplified surveying feature achieves ease of introduction even for first-time users. The main reason is, as noted, the simplicity of operation. The dedicated app automates specialized operations and provides an intuitive interface, so site staff without surveying expertise can use it without trouble. Complex coordinate system settings and positioning calculations are processed in the background; the user simply follows on-screen guidance to move the smartphone and complete the survey. Even those who are new to surveying can use it with the same feel as a smartphone app.

Another point is the low barrier to equipment adoption. The LRTK receiver is pocket-sized and lightweight, with no special installation work or licensing required. There is no need for traditional tripod setups or leveling, and surveying can begin within minutes of arriving on site. LRTK services also support subscription plans, providing options to start operation without a large initial investment. This makes it easy for small and medium exterior contractors to adopt LRTK and use it flexibly for only the periods they need. Lower cost barriers make it easy to try LRTK on a trial basis.

Above all, LRTK was developed with the concept of “high-precision surveying anyone can do,” and it can truly become the standard tool on future construction sites. In fact, there are increasing cases in construction and landscaping where less-experienced technicians use LRTK for surveying and succeed in improving productivity. LRTK, which makes advanced surveying techniques accessible on site, is a powerful ally in promoting DX in exterior work. If you feel issues with your current surveying workflows, why not try smartphone-completed LRTK surveying? Even first-time users can quickly experience its effects, and your approach to exterior work may evolve to the next level.