Must-see for Exterior Contractors! How LRTK Is Changing On-site Measurement and Design for Exteriors

Accurate surveying at exterior (residential outdoor) construction sites is a critical factor that determines both construction quality and efficiency. However, traditional on-site surveying often requires significant time and effort, and discrepancies between drawings and the field due to surveying mistakes frequently cause rework.

This article first summarizes the challenges of on-site surveying in the exterior industry and the causes of inconsistencies between drawings and actual sites. Then it explains how the arrival of the latest surveying technology, LRTK, transforms on-site measurement and the design process. We will look in detail at specific LRTK features, field usage workflows, and the benefits of adoption for different roles—site managers, designers, and business owners. Finally, we’ll introduce key points for implementing and using LRTK. This is a helpful guide to on-site DX for those involved in exterior construction.

Challenges of Exterior On-site Surveying

Traditional surveying methods used on exterior construction sites have several challenges. Analog measurements using total stations (TS), auto levels (optical levels), tape measures, and spirit levels require experience and manpower to achieve high accuracy. For example, team-of-two workflows where one person marks reference points while another measures distances with a tape measure and marks points must be repeated—so surveying large sites or yards with complex shapes can take an entire day. Because the work is manual, small errors and human mistakes are inevitable.

The main issues can be summarized as follows:

• Personnel and time burden: Surveying typically requires two or more workers, and preparation through cleanup takes time. When there are many points or the site has large elevation differences, surveying and marking can take a full day, significantly reducing productivity.

• Surveying errors and human error: Reading and recording tape measurements manually carries the risk of slight misreads or transcription mistakes. For instance, writing down 508 cm instead of 503 cm can cause a 5 cm error. Stakes or chalk marks may fade or be erased during construction, necessitating re-measurement. Such mistakes create discrepancies between drawings and the site and often lead to rework.

• Constraints from site conditions: On narrow sites or sites with many obstacles, traditional surveying instruments may not have clear lines of sight or adequate setup locations, forcing indirect measurements. This increases steps and complicates accuracy control—especially for marking curves or slopes in complex gardens.

• Labor shortage and aging workforce: The construction industry is facing a serious shortage and aging of personnel who perform surveying. Methods that rely on experienced surveyors are hard to sustain, so it is urgent to reduce the labor required for surveying and improve efficiency so a limited workforce can manage sites. The Ministry of Land, Infrastructure, Transport and Tourism is promoting productivity improvements via ICT through initiatives like i-Construction, and the exterior sector is no exception.

Causes of Discrepancies Between Drawings and the Site

Errors and information gaps caused by the challenges described above lead to mismatches between design drawings and actual construction results. The main causes include:

• Inconsistent reference elevations and reference points: If the main building and the exterior use different reference elevations (ground levels) or surveying reference points, they may appear consistent on paper but be misaligned during construction. If the building contractor and the exterior contractor do not unify baseline lines or reference points during design, differences such as unexpected step heights on the entrance approach can occur.

• Variability in surveying accuracy and changes over time: Exterior work often starts after the building is completed, so the ground may settle between foundation work and exterior construction, or temporary leveling stakes may shift or disappear. Also, when building and exterior work use separate surveys, small errors from differing equipment or methods can accumulate, producing discrepancies between drawings and the site.

• Lack of current site information: If site surveys at the design stage fail to capture subtle slopes, level differences with neighboring properties, or the exact locations of existing structures, design changes and on-site adjustments may be needed during construction, resulting in a final product that differs from the original drawing. For example, adjusting heights during construction to maintain drainage slopes can produce finished results that differ from the drawing.

• Insufficient information sharing and coordination: When surveying data and design intent are not adequately shared between building and exterior personnel, misreading drawings or misunderstandings can cause construction errors. It is especially important to share accurate coordinate information among stakeholders for critical areas like structures near property boundaries.

These factors overlap and cause situations where work that was believed to follow the drawings ends up misaligned. So how can we close the gap between on-site measurement and design?

How On-site Measurement and Design Processes Change with the Arrival of LRTK

A new solution that can address these challenges is LRTK. LRTK (pronounced “el-ar-tee-kay”) is a compact, high-precision GNSS positioning device that attaches to a smartphone. Paired with an iPhone or iPad, it enables centimeter-level positioning easily. This allows surveying tasks that previously required specialists and specialized equipment to be performed quickly and accurately by a single person—essentially “iPhone surveying” bringing on-site DX.

Using LRTK for on-site measurement links the smartphone’s camera and LiDAR sensor with high-precision GNSS, scanning the surroundings while walking to capture detailed point cloud data. All captured points are assigned absolute coordinates in a geodetic reference frame, so it’s easy to compare them later with design drawings or BIM models and to calculate earthwork volumes. Even complex gardens or sites with large elevation differences can be digitally recorded in detail, allowing designers to understand actual site conditions from the planning stage. Tasks that once required expensive 3D laser scanners and multiple personnel can now be accomplished by one person in a short time with LRTK.

This also fundamentally changes the design workflow. Designers using high-accuracy as-built data captured by LRTK can prevent mismatches between drawings and the site before work begins. Importing point clouds or measured coordinates into CAD software makes it possible to plan based on measured terrain and building-adjacent dimensions. This reduces cases where height plans conflict with actual site slopes and require on-site adjustment. LRTK also enables design verification via AR display on the smartphone. By overlaying design drawings or 3D models at full scale on the site, you can check for potential issues—such as whether a gate’s swing will be obstructed—before construction. The AR display maintains accurate position and scale thanks to LRTK’s GNSS-based position correction, which is a major strength. Additionally, LRTK can instantly sync all captured data to the cloud, allowing on-site measurements to be shared immediately with office colleagues or clients. By removing the boundary between the site and design, and ensuring everyone references the latest accurate data, measurement and design processes for exterior work become dramatically more efficient.

Main Features of LRTK and Field Usage Workflow

Let’s look at the main features LRTK provides along the flow of an exterior project.

• Preliminary site survey (high-precision positioning and point cloud scanning) On-site, attach the LRTK device to a smartphone, launch the app, and start surveying. Simply walking around the site with the phone lets the built-in LiDAR and camera automatically scan the surroundings to capture a dense 3D point cloud. At the same time, LRTK measures and records coordinates of each point with centimeter accuracy, allowing you to capture the entire site’s terrain and existing features as a geo-referenced digital model. Use the photo positioning function to record coordinates and orientation of specific objects simply by taking photos with the phone, ensuring detailed information is not missed.

• Using the data for design (cloud sync and drawing comparison) Point cloud data and measured coordinates can be uploaded from the field to the LRTK cloud with a single tap. Office-based designers can immediately review the site’s point cloud model and measurement data on the cloud, compare the current state with drawings, and compute required dimensions. For example, designers can accurately determine site elevation differences and distances to property boundaries from the desk, reducing the need for additional site visits. Point cloud data can be imported into CAD software as a base for design, dramatically improving planning accuracy and speed. Because the team shares the same latest data in the cloud, information gaps between drawings and the site can be resolved early.

• Use during construction (AR-based design verification and coordinate guidance) During construction, LRTK helps ensure construction accuracy. The LRTK app’s AR function overlays uploaded design drawings or 3D models onto the real site so you can verify on-site whether placements deviate from planned positions at full scale. For instance, you can display a fence layout line in AR on the ground to confirm the required setback from the neighboring boundary is maintained. The coordinate guidance (AR navigation) feature also shows the direction and distance to a target point in real time on the phone screen, enabling you to locate stake positions or buried boundary markers that have no physical markers. Even less-experienced staff can quickly and accurately set out positions, greatly reducing the errors and labor associated with traditional marking work.

• As-built verification and records upon completion (as-built measurement and reporting) At project completion, use LRTK to measure and record the as-built condition. Re-scan the site to obtain 3D data of completed structures and ground shapes, and compare these with design drawings or pre-construction data to verify deviations. For example, you can calculate actual excavation or fill volumes from point clouds to check for discrepancies from estimated quantities. The captured as-built data and geo-tagged photos are saved to the cloud, useful for preparing reports for clients and as reference material for future renovations. Accurate digital records preserve information that paper drawings and photos might not convey.

Role-specific Benefits of Implementing LRTK

The benefits of adopting LRTK vary by role. Here are the main advantages for site managers, designers, and business owners.

• Site managers: Because surveying can be completed by a single person in a short time, manpower allocation and working hours are greatly reduced, allowing focus on other site management tasks. High-precision surveying reduces construction mistakes and rework, shortening schedules and enabling smoother progress management. Immediate sharing of measurement data and site photos via the cloud speeds up reporting and communication with the office or clients, improving onsite efficiency and reliability. AR functionality allows on-site verification of drawings, enabling more accurate instructions and inspections.

• Designers: Using as-built point clouds and precise coordinate data lets designers recreate the site accurately at the desk and prevents design errors due to insufficient site surveys. Being able to measure required dimensions and elevation differences in the data reduces additional site measurements and rework, greatly improving design efficiency. Presenting finished visuals in AR to clients makes design intent easier to convey and smooths consensus building. Design-time verification with construction in mind minimizes discrepancies between drawings and the site.

• Business owners: Improved efficiency in surveying and construction cuts unnecessary labor and rework costs, improving project profitability. Shorter project durations from labor savings free up capacity to take on more projects, creating opportunities for revenue growth. Delivering higher-precision, higher-quality construction through advanced technology increases client satisfaction and can lead to more repeat and referral business. Implementing leading-edge approaches also enhances corporate credibility externally, aiding recruitment of talented staff and strengthening relationships with subcontractors.

Points for LRTK Implementation and Use

Finally, confirm the following points to maximize the benefits of introducing LRTK to your sites.

• Check the positioning environment: Verify beforehand whether stable GNSS positioning can be achieved at the actual site. In mountainous or mobile-signal-poor areas, LRTK’s support for the quasi-zenith satellite system’s augmentation signals may be useful, while in urban areas be mindful of satellite blockage or signal reflection (multipath) caused by tall buildings. Check the sky visibility and surroundings and, if necessary, select positioning points in advance.

• Prepare devices and smartphones: Ensure the LRTK GNSS receiver and the smartphone used for connection (recommended: iPhone/iPad) are ready. Verify that the device you plan to purchase has the latest firmware and supports the positioning signals you need and has adequate continuous operation time. Install the dedicated LRTK app on the phone and pair or test connections in advance for Bluetooth or direct Lightning connections. Fully charge batteries before surveying and carry a mobile battery for long work.

• Cloud use and data management: Using the LRTK cloud service is key to team utilization of positioning and point cloud data. Complete account registration and set up project-level folders and internal data management rules. On first use, try uploading point clouds and photos as a test and confirm that they can be viewed in a browser. Organized cloud data makes it easy to manage multiple concurrent projects.

• Safety measures: When surveying alone, never neglect safety. Be aware of heavy equipment and vehicle traffic while working. Wear basic protective gear such as helmets and reflective vests, and place cones to indicate surveying is in progress. Share the work date and location within the company in advance and set regular check-in times and emergency contact methods. Operating with safety as a priority ensures sustained benefits.

• Operation training: Become familiar with LRTK operation before entering an active site. Practice the app’s positioning button, photo-based coordinate recording, and point cloud scanning procedures. For example, conduct measurements at a nearby site and verify correct coordinates at a known reference point. If possible, also test the coordinate guidance feature and the process to upload captured data to the cloud for office review. Pre-training helps users operate calmly during real work.

• Phased introduction: When introducing LRTK for the first time, it’s advisable to start with small pilot projects rather than immediately deploying it on large projects. Initially run it in parallel with traditional surveying methods to compare results and validate data accuracy and operating workflows internally. Field staff may be hesitant at first, but gradually expanding the application scope helps smooth adoption.

Conclusion

LRTK offers a wealth of intuitive “easy surveying” features that anyone can master without specialized skills. For example: photo positioning, which records accurate coordinates of objects simply by taking a smartphone photo; AR display, which overlays drawings or 3D models on the real site; cloud sync, which shares captured data across the team immediately; monopod measurement, which uses a dedicated lightweight pole to quickly measure height and position by one person; and coordinate recording, which saves measured coordinate data with a single tap for management. By using these functions, non-expert staff can easily capture and utilize accurate on-site data. The approach to on-site measurement and design in exterior work is already starting to change with the adoption of LRTK. You can expect not only efficiency gains, but also improved quality through higher accuracy and better communication. Those involved in exterior construction should consider trying LRTK and experiencing the next-generation style of on-site surveying.