How Designers Use LRTK: Why Exterior Planning Is Changing

In the field of exterior design, understanding the site conditions and conducting accurate surveys determine whether a plan succeeds or fails. If the site shape, elevation differences, boundary lines, and existing structures are not correctly understood, a carefully drawn exterior plan may not fit the actual site and could require rework. As an exterior designer myself, I have long felt the burden of traditional site surveys and the limitations of survey accuracy. However, in recent years, the emergence of high-precision positioning systems usable with smartphones—LRTK—has begun to dramatically change the exterior planning process. In this article, I will detail those concrete changes and benefits from a designer’s perspective.

Field surveys are essential to exterior design

In exterior design (house exteriors and gardens), it is crucial to start with an on-site survey and measurement to accurately grasp the current conditions. There are many factors that affect design: site dimensions and shape, boundary positions with neighboring lots, arrangement of buildings and walls, ground elevation differences and slopes, drainage, presence of existing trees or retaining walls, and so on. If these are not understood in advance and reflected in drawings, problems can occur at the construction stage—such as a fence being placed over the boundary or misreading a slope leading to poor drainage. In particular, confirming site boundaries and measuring elevation differences are important to avoid neighborhood disputes and to properly manage stormwater; even small errors can cause major problems.

Therefore, precise measurement and careful verification are indispensable in site surveys. It is necessary to meticulously gather the data that forms the basis for drawing design plans, such as locating boundary stakes, measuring setback distances from buildings, and leveling ground elevations. For exterior designers, as-built surveys are unglamorous work, but neglecting them leads to corrections and rework later in the process and affects client trust. High-quality proposals are backed by accurate field surveys.

Traditional surveying methods and their challenges

However, we designers have faced several challenges with traditional surveying methods. For exterior site surveys, practitioners typically use tape measures, laser distance meters, and levels to manually record dimensions, or they hire surveyors who use specialized equipment such as total stations. In the former case, large sites cannot be measured by one person alone and require at least two people, making the measure→mark→measure again procedure time-consuming. Tape sag can introduce slight errors, and repeated re-measurements mean unavoidable human effort and mistakes. Even when hiring professional surveyors, scheduling and outsourcing costs occur, and if something is missed you must call them back—reducing agility.

Traditional surveying also carries the constant risk of human error. Mistaking handwritten dimensions or transcribing measured values incorrectly can easily create centimeter-level discrepancies. Even experienced craftsmen find it difficult to eliminate manual errors entirely. Urban infill sites, where buildings or walls obstruct straight-line measurement or line-of-sight, present physical constraints—making it impossible to stretch a tape measure to the desired points. As a result, some measurements were guessed, or re-measured later, creating inefficiencies.

Against this backdrop of traditional-method limitations, the desire common among exterior designers has been: “I want to measure accurately and quickly on site” and “I want to measure everything correctly in one go.” Responding to these needs, devices using the latest surveying technology—RTK (Real-Time Kinematic) GNSS—have appeared.

What is smartphone-capable high-precision surveying “LRTK”?

With RTK-GNSS, a satellite positioning technology that improves precision, small surveying devices that can be used with smartphones have recently appeared. The leading example is LRTK. LRTK is a positioning system that uses an ultra-compact RTK-GNSS receiver, pocket-sized, attached to a smartphone, allowing designers to perform centimeter-level surveying with ease. Attach the dedicated case-type device to your smartphone with one touch—no complicated wiring is required—and you can start using it immediately. The weight is only a few hundred grams, making it lightweight and easy to carry. Its compactness has led to it being called a “surveying instrument that fits in your pocket,” and the idea of one device per person in their pocket heading to site has become realistic.

Using the LRTK device and a dedicated app, your smartphone instantly becomes a high-precision surveying instrument. With the RTK method that uses real-time satellite correction information, the errors that were several meters with standalone smartphone GPS shrink to below several centimeters. For example, simply pointing the smartphone at the point you want to measure and tapping a button allows you to instantly obtain the latitude, longitude, and elevation of that location. Accuracy within a few centimeters matches the methods of experienced surveyors and is sufficiently reliable as foundational design data. The app also shows satellite reception status and positioning accuracy, making it user-friendly so even beginners can ensure precision.

How high-precision surveying and point-cloud scanning change the design process

What makes LRTK remarkable is that it not only measures point coordinates but can digitize the entire site. By working with a smartphone camera or LiDAR sensor (on compatible models), you can record surrounding structures and terrain as three-dimensional point-cloud data simply by walking around the site. Point-cloud measurement, which used to require expensive 3D laser scanners, can now be achieved easily with the LRTK and a smartphone. I actually scanned a residential exterior site with LRTK, and the door posts, trees, and ground undulations were reproduced in the data with surprising detail.

This point-cloud data is extremely useful for design afterward. You can freely measure distances between any two points on the acquired point cloud or analyze elevation differences. That greatly reduces situations where you find a missed spot and have to return for re-measurement. Once scanned, you can revisit the data in the office and extract dimensions. You can also overlay the point cloud with traditional CAD design data to verify whether the planned design will fit the existing conditions. For example, you can simulate whether a designed carport column will be correctly positioned relative to the actual site on the point cloud, preventing mistakes. Because LRTK digitizes the site “as is” and feeds that into design, both the accuracy and efficiency of planning improve drastically.

Furthermore, LRTK streamlines the surveying task itself. What used to require a surveying team and half a day can be completed by a single designer in a short time with LRTK. Even thoroughly measuring a site takes only tens of minutes to about an hour, and on simple terrain you can record the main points in just a few minutes. There is no need to carry heavy tripods, and you can move lightly even in narrow or high places, enabling you to tackle detailed measurements that were previously avoided. The era when “surveys must be left to specialists” is shifting toward an era where “you can quickly measure it yourself when needed,” and the design process itself is starting to change.

Improved proposals through cloud use and AR sharing

Another great feature of LRTK is that data collected can be uploaded to the cloud instantly on site. From the LRTK smartphone app, you can save and share survey results, point-cloud data, and site photos to your company cloud with one button, eliminating the need to return to the office and transfer data via USB. Coordinates measured on site are plotted on a cloud map in real time and can be viewed immediately by all team members. In my office, for example, a designer might measure with LRTK in the morning and another staff member can start creating CAD drawings from that cloud data in the afternoon—enabling very fast collaboration. By connecting the site and office in real time, the overall project pace has increased markedly.

A further advantage of storing data in the cloud is easy management of surveying history. If you want to recheck data from a previously measured site, you can log into the cloud to retrieve point clouds and surveyed point information by date and location. There is no need to rummage through paper notebooks, and data loss worries are eliminated. For designers, having the as-built site data from projects preserved as assets is reassuring; past data can be referenced for similar projects, contributing to knowledge accumulation.

LRTK also transforms exterior presentations by combining with AR (augmented reality). You can overlay a 3D model of the designed exterior plan onto the live view of the actual site on a smartphone or tablet. While perspective drawings and CGI renderings have traditionally been used to convey images, AR projects the plan directly onto the site, dramatically increasing client understanding. For example, you can show the image of a proposed terrace or garden on a tablet while standing on the site, displaying the “finished look” in place. Because LRTK provides centimeter-level accuracy (half-inch accuracy), the AR-displayed design aligns accurately with reality, appearing as if it has actually been built there. Clients are often delighted, saying “It’s exactly how I imagined it! Please proceed with this plan,” and agreement-building proceeds smoothly more often.

AR applications also include visualizing buried utilities. Exterior work often has pipes or cables underground, but if you record their locations with LRTK beforehand and display them in AR on the ground, designers and construction supervisors can intuitively share information like “the sewer line runs from here to here.” Such uses improve the quality of proposals and meetings and smooth communication among designers, clients, and contractors.

Planning that fully accounts for retaining walls, steps, and slopes

Exterior planning must consider elevation differences and the interactions of structures on and off-site. For example, if there is a retaining wall near the boundary with a neighboring lot, misjudging its height or position affects fence installation plans and the amount of fill required. When the site contains steps or level changes, consideration of pedestrian flow and accessibility is necessary; and depending on the overall slope, drainage routes must be carefully designed. For exterior plans that involve earthworks (cutting or filling), it is also necessary to accurately calculate how much soil will be moved.

In assessing these elements, the detailed as-built data from LRTK is extremely helpful. You can extract the top-of-wall elevation and position from point-cloud data accurately, allowing you to adjust the heights of new fences or garage floors by millimeters. Ground slope can be calculated from height data at points, enabling quantitative judgments such as “this spot has a 2% slope, so drainage gradient is acceptable.” Steps and level differences are immediately apparent, so you can include measures like ramp installation where needed.

Especially useful are earthwork volume calculations and cut-and-fill assessments. By creating a ground height model from the point cloud, you can automatically compute the earth volume to be moved by comparing it to planned ground elevations. Where earthwork estimates were previously done roughly by rule of thumb or hand calculations, LRTK data allows high-precision computation, resulting in well-balanced plans. Consequently, omissions in considerations of retaining walls or slopes decrease, and the accuracy of plans at the design stage improves dramatically. I used to compromise with “we’ll fine-tune heights after construction starts,” but now I can simulate in advance to derive the optimal solution. Because LRTK captures the site comprehensively, designers can focus on planning with confidence.

Case studies: LRTK proves powerful on narrow and sloped sites

What I found after adopting LRTK is its flexibility to handle any site. In a central-city narrow lot case, where traditionally I needed an extra hand to measure every corner or struggled to get into the gap between neighboring houses, LRTK allowed me to handle it alone. Holding a smartphone and walking the site, I recorded survey points in narrow passages and right up against buildings. As a result, I obtained a precise plan and terrain data for the whole lot in a short time. Because nothing was left unmeasured, there was no need for later supplementary surveys or client follow-ups, allowing me to meet tight schedules and submit plans smoothly.

On sloped sites, LRTK’s true value was especially clear. With marked elevation differences, traditional surveys required multiple leveling measurements to draw contour lines, but LRTK point-cloud scanning captured the entire terrain, showing slopes, valleys, and fill areas at a glance. Based on that data, I planned stair placements and additional retaining walls to resolve level differences and verified them with 3D models during the planning stage, making design proposals far more persuasive. Three-dimensional model reviews are effective when explaining to clients—showing visually “we will cut this slope by this much to level it” eases client concerns. Exterior design on slopes used to be high-risk and approached cautiously, but with LRTK I was able to propose solutions confidently.

LRTK is also useful on typical residential exterior remodels. For projects renovating an old garden, we recorded the positions of existing garden stones and plantings as a point cloud and used that to decide what to relocate or remove. By overlaying new and existing plans on the point cloud, interference checks with existing elements can be performed quickly, enabling rational planning that avoids unnecessary construction. From narrow lots to sloped sites and renovation projects, LRTK becomes a strong ally for exterior designers.

LRTK’s usefulness and the future from a designer’s perspective

From an exterior designer’s standpoint, LRTK’s strengths are its responsiveness and versatility. The assurance of being able to measure yourself whenever needed, and the convenience of having the acquired data flow seamlessly through design, construction, and presentation, make it indispensable once experienced. The app is intuitive, automating difficult coordinate transformations and survey calculations, so people without specialized knowledge can use it. Young staff or those inexperienced in surveying can master it in a short time, lowering the adoption barrier across an organization. In my network, many initially skeptical people now say, “After trying it, everyone in the office can survey, and our efficiency has increased.”

Looking at the industry as a whole, it’s likely that easy-to-use high-precision surveying tools like LRTK will become standard. As DX (digital transformation) progresses in construction—initiatives like i‑Construction advocated by the Ministry of Land, Infrastructure, Transport and Tourism—environments that allow anyone to perform precise surveys are essential. Exterior survey work used to rely on experienced craftsmen, but going forward, digital tools will enable newcomers to achieve results comparable to veterans in short time. LRTK’s simplified surveying exemplifies this shift.

In exterior planning, LRTK supports the entire workflow from site survey to design, presentation, and construction follow-up. Once you experience its benefits, it becomes an indispensable partner for designers. Since I started using LRTK, I feel lighter going to sites and more confident in my proposals. I encourage you to try this easy-to-use new surveying tool and experience improved efficiency and quality across your work. You will likely be surprised by its simplicity and accuracy, and it will change how you approach exterior design. I strongly feel that the wave of simplified surveying via LRTK is steadily spreading and may soon become the standard style in the exterior industry.

Detailed product information and case studies are also available on the [LRTK official site](https://www.lrtk.lefixea.com), so please check it out if you are interested. Why not bring a new form of planning that uses LRTK into your design sites?