Five Major Benefits of As-Built AR Checks: Dramatically Improve Site Efficiency and Quality

Table of Contents

• What Is an As-Built AR Check

• Issues with Traditional As-Built Verification

• Benefit 1: As-Built Verification That Misses No Errors at the Millimeter Level

• Benefit 2: Dramatic Improvements in Inspection Efficiency and Consensus Building

• Benefit 3: Digitalization of As-Built Records and Reliable Proof of Quality

• Benefit 4: Labor Savings through Easy Surveying Anyone Can Use

• Benefit 5: Site DX via Remote Supervision and Cloud Sharing

• As-Built AR Checks Enabled by LRTK Simple Surveying

• FAQ

What Is an As-Built AR Check

As-built management (as-built verification) is a quality-control process in civil engineering and construction that measures and confirms whether completed structures and terrain have been constructed according to design drawings. Traditionally, heights and thicknesses at each point were measured with total stations (TS), levels, tape measures, etc., results were recorded on paper, and pass/fail determinations were made back at the office by comparing with drawings. However, this method often creates time lags between on-site measurement and problem detection, which can cause rework. Surveying has also relied heavily on the experience and intuition of skilled technicians, and with chronic labor shortages and an aging workforce, improving efficiency has become a major challenge.

Against this backdrop, As-Built AR Check has attracted attention. Using AR (Augmented Reality) technology, it overlays 3D design models and measurement data onto smartphone or tablet camera images, allowing a new method of directly verifying as-built conditions on site. Whereas as-built verification was previously done on paper drawings or numeric data, this approach lets even inexperienced technicians intuitively judge the quality of finishes by directly comparing real objects with digital information on the spot.

Especially when combined with high-precision GNSS (satellite positioning), the models and data displayed in AR can be accurately aligned with actual structures within an error of a few centimeters (a few in). Smartphone + RTK-GNSS enables centimeter-level positioning, allowing AR overlays to match the real object without noticeable offset. Modern iPhones and iPads also include LiDAR sensors, and advanced uses include comparing point cloud data (a dense 3D point scan of current conditions) obtained by these sensors with design data to visualize differences. The Ministry of Land, Infrastructure, Transport and Tourism is also promoting the use of 3D measurement and AR within its “i-Construction” initiatives, and As-Built AR Check is increasingly expected to be a solution that simultaneously improves on-site efficiency and quality.

Issues with Traditional As-Built Verification

To understand the benefits of As-Built AR Check, let’s first organize the main issues of traditional as-built verification methods. Conventional methods had the following problems:

• Time-consuming and labor-intensive: Staff painstakingly measured each point using surveying instruments and tape measures and recorded results on paper. For large-scale works with many measurement points, measurements and drawing comparisons could take days.

• Dependence on skilled personnel: Accurate measurement and evaluation require experienced surveyors, and some tasks often required two-person teams. With labor shortages and an aging technical workforce, it became difficult to secure adequate personnel on each site.

• Need for expensive equipment: To measure design deviations at the millimeter level requires high-precision TS or GNSS receivers and other specialized surveying instruments, which involve very high initial investments and are difficult for small and medium-sized companies to introduce. Maintenance costs and theft risks are also non-negligible.

• Risk of human error: Manual measurement is prone to human errors such as miswritten notes or transcription mistakes later. Missed measurements found afterwards could require returning to the site and remeasuring.

• Late problem detection: Inspections were often performed back at the office, so defects were not always noticed on the spot and could become too late to fix easily. For example, if insufficient concrete thickness or subgrade slope is noticed a day later, materials may have hardened and rework could become a major undertaking.

• Burden of documentation: As-built management requires preparing drawings and reports based on measurement results and submitting them to the client. Traditionally, preparing these documents took significant time and effort and was a heavy burden for the person in charge.

Because of these issues, traditional as-built verification was inevitably inefficient and carried a risk of overlooking quality problems. To perform real-time and precise as-built checks, the use of new technologies became indispensable.

Benefit 1: As-Built Verification That Misses No Errors at the Millimeter Level

One of the greatest benefits of As-Built AR Check is that it can detect construction errors and finish deviations at the millimeter level without missing them. By overlaying design data onto camera images, subtle height differences and insufficient thicknesses that are hard to notice with the naked eye are instantly visualized.

For example, in road embankment work, scanning the finished surface with a smartphone to obtain point cloud data and comparing it on-site in AR with the design reference model makes minor unevenness and slope defects immediately apparent. If height differences are displayed as a color-coded heat map, it becomes intuitive to see “which point is how many cm higher/lower than the design.” As a result, mistakes that even experienced personnel might have overlooked can be reliably detected and corrected early, preventing quality issues.

Moreover, visual checks using AR reduce human errors such as misreading numbers. Because you can compare drawings and the real object side by side, inspection accuracy improves dramatically compared to relying on numbers alone. Buried utilities that become invisible after completion can also be checked by displaying a previously scanned point cloud model in AR through the surface; for example, if a sewer pipe is recorded in 3D before backfilling, its alignment and depth can be confirmed on a smartphone screen after paving is complete, reducing the risk of accidental damage in later processes. As-Built AR Check captures even small on-site deviations and greatly contributes to preventing quality troubles.

Benefit 2: Dramatic Improvements in Inspection Efficiency and Consensus Building

Using AR dramatically speeds up inspection work and consensus building with clients and supervising engineers. Because wide areas can be measured in 3D at once, it takes far less time than measuring point by point, and software can automatically analyze measurement results and determine pass/fail.

For example, using drone photogrammetry or iPhone LiDAR scans, slope as-built measurements that used to take half a day can sometimes be completed in tens of minutes. The acquired point cloud data can be compared to design data in the cloud, and deviations from standards are immediately highlighted. The person in charge can understand the inspection results on a tablet screen on the spot. This eliminates the need to punch numbers into a calculator or mark up drawings with a red pen one by one.

Also, AR’s 3D display makes it easier for all stakeholders to understand, smoothing explanations and inspection attendance with clients and supervisors. Clients who previously only heard “numerical reports” can feel more assured when they visually confirm the deviation between the as-built and the design through a tablet on site. Even in remote attendance (remote inspection) scenarios, sharing the site AR images allows the office side to accurately confirm the situation and reduces communication loss. This visualization effect enables reliable consensus building with the client and dramatically streamlines the approval process.

Benefit 3: Digitalization of As-Built Records and Reliable Proof of Quality

As-Built AR Check also digitizes on-site as-built records comprehensively, serving as reliable proof of quality. Once you perform a 3D scan and obtain point cloud data, there are no “missed measurements” or “missed photos,” and you can comprehensively record construction results. Works that used to be inferred from a few critical measurements can now be understood in detail across the entire structure using 3D data.

The acquired high-precision point clouds and geotagged photos become digital inspection records. If you automatically generate color-coded difference maps or cross-section comparison diagrams, you can objectively prove compliance with standards even if questioned later. Tiny deviations that were difficult to convey on paper drawings can be shown clearly on a 3D model, improving the explainability of as-built management.

Furthermore, these digital records can be securely stored and shared in the cloud, making electronic delivery to clients easy. The automation of inspection document creation reduces the reporting workload of site supervisors. When planning similar works in the future, past as-built data can serve as reference material, enabling data-driven decision making. Digital proof of quality through As-Built AR Check contributes to long-term reliability and accumulation of know-how.

Benefit 4: Labor Savings through Easy Surveying Anyone Can Use

The latest AR check tools run on smartphones and tablets, enabling easy surveying that anyone can use without familiarity with specialized instruments. For example, smartphone surveying systems such as LRTK allow high-precision positioning and scanning simply by following app instructions, without complex settings or difficult calculations. Intuitive UIs and workflows are provided so that even novice technicians can operate them, enabling as-built data acquisition and checks at a consistent accuracy even when a licensed surveyor is absent from the site.

Because digital measurement can record wide areas at once, it also greatly reduces manual labor. If surveying that used to require two people can be done by one, labor costs and personnel coordination burdens are reduced. There is no need to carry heavy equipment around the site, nor to spend time setting up or packing away instruments. As a result, sites can operate with limited personnel, reducing the physical and mental burden on workers.

The spare capacity created by labor savings can be redirected to other quality-control or safety-management tasks. As-Built AR Check realizes smart construction that is less dependent on people and can be a trump card for addressing worsening labor shortages.

Benefit 5: Site DX via Remote Supervision and Cloud Sharing

The combination of As-Built AR Check and cloud technology promotes site digital transformation (DX) that lets you understand the site remotely. 3D data and AR footage acquired on site can be shared across the company and externally via the cloud immediately, enabling supervision and support of multiple sites in real time from the office.

For example, if site staff upload a scanned point cloud model or live AR footage from a smartphone to the cloud, headquarters engineers or clients can check as-built conditions from their desks. They can add comments to the data or issue additional instructions remotely as needed. With remote attendance, inspections and meetings can be held without travel, reducing travel time and cost and accelerating decision making.

Also, as-built data accumulated in the cloud is always available to stakeholders as the latest information. Sharing drawings and point cloud data online among all parties eliminates time lags caused by “not having the latest data on hand,” making information flow between site and office, and between client and contractor, seamless and transforming construction management workflows. In this way, a remote supervision system that leverages AR and data sharing could become the future standard for smart construction sites.

As-Built AR Checks Enabled by LRTK Simple Surveying

To maximize the effect of As-Built AR Check, a supporting surveying and data-processing system is indispensable. LRTK simple surveying is an all-in-one solution designed to make AR checks easy to practice.

LRTK is a high-precision positioning and measurement system that leverages smartphones, and with just an iPhone and a compact GNSS receiver you can complete on-site surveying and as-built verification. RTK-GNSS achieves centimeter-level positioning—horizontal ±1–2 cm (±0.4–0.8 in) and vertical ±3 cm (±1.2 in)—allowing positions to be determined with accuracy comparable to dedicated instruments. Based on those high-precision coordinates, you can project design models in AR on site and compare them with point cloud data. Stable AR displays without position drift let anyone perform intuitive as-built checks not possible with paper drawings.

Moreover, LRTK includes point cloud acquisition functions that utilize the iPhone’s built-in LiDAR sensor and camera. Even complex-shaped structures can be scanned with a smartphone to generate high-precision 3D point cloud models. Since the acquired point clouds are tagged with absolute coordinates derived from RTK-GNSS, they can be immediately used for comparisons with design data or volume calculations. Also, recording measured point coordinates and later using them for stakeout or installations is made easy by LRTK’s coordinate guidance (coordinate navigation) function. Simply follow the guidance on the smartphone screen to be led to the specified coordinate point within a few centimeters (a few in), making single-person stake positioning—previously difficult—simple.

By providing AR display, point cloud acquisition, coordinate guidance, and as-built verification on a single platform, LRTK simple surveying seamlessly connects tasks that used to require separate instruments and software. You can complete the workflow—upload scanned point clouds to the cloud, immediately check differences in AR—within a single smartphone app, accelerating on-site DX. LRTK is already being introduced at construction sites across the country, contributing to faster disaster recovery and more efficient construction management. Even those who wonder “I want to try As-Built AR Check but don’t know how to start” can begin operation in a relatively short period using LRTK. LRTK simple surveying, which balances the adoption of the latest technology with ease of use, should become a reliable ally for future sites.

FAQ

Q: What is needed to introduce As-Built AR Check on site? A: Basically, a tablet or smartphone, a high-precision GNSS receiver, and an application that supports As-Built AR Check are sufficient. For example, solutions like LRTK enable centimeter-level positioning by simply attaching a compact GNSS antenna to a commercially available iPhone or iPad, and the dedicated app can handle 3D design data and point clouds. With design drawing data (BIM/CIM models or electronic drawings) and site reference point coordinates prepared, you can start AR checks on the spot.

Q: Is the accuracy of AR-based as-built verification reliable? A: Yes—when combined with high-precision GNSS, AR can achieve sufficiently reliable accuracy. Ordinary smartphone GPS has errors of several meters (several ft), but with RTK corrections the error can be reduced to a few centimeters. LRTK simple surveying has confirmed approximately 1–2 cm horizontal accuracy, comparable to conventional first-class survey instruments. Because AR overlays align with the real object, centimeter-scale steps and gaps can be reliably detected. For critical areas, combining AR displays with point cloud measurement data enables millimeter-level accuracy verification.

Q: Can As-Built AR Check be used for public works inspections? A: Currently, the Ministry of Land, Infrastructure, Transport and Tourism is actively promoting ICT construction and 3D as-built management, and the use of AR has been demonstrated. Trial projects have shown practices such as inspecting as-built by overlaying design models on a tablet AR screen. Although AR is not yet explicitly specified in formal inspection procedures, cases of incorporating AR checks into supervision and inspection—combined with point cloud surface management and remote attendance—are increasing. If guidelines are developed in the future, As-Built AR Check could become established as part of official inspection methods.

Q: Is operating AR checks difficult? Can young or inexperienced personnel handle them? A: The operation is intuitive, and young or digitally inexperienced personnel can become proficient with short training. Measurement and AR display can be performed with the feel of taking photos using a smartphone app, so special surveying skills are not required. The site data used are preprepared design models and drawings, so you just select files in the app and follow the instructions. Tools like LRTK simple surveying with thoughtfully designed UIs let anyone perform accurate as-built checks by following on-screen guidance. Results are visually displayed and easy to understand, facilitating information sharing within the team.

Q: What kinds of works and sites are As-Built AR Checks effective for? A: They can be used in any situation where you need to verify deviations between design and actual construction, across civil engineering and architecture. For large earthworks such as roads and land development, AR heat maps are effective for wide-area elevation control; for structures such as tunnels and dams, 3D model comparisons help check thickness and shape. In architecture, AR can be used to compare columns and walls against BIM models in superstructure work or to precheck MEP clashes. In short, As-Built AR Checks are effective wherever you want to verify construction results on the spot. The benefits are greatest in processes where remeasurement or rework costs are high.