Using Laser Scanners for Building Information Modelling (BIM)

Laser scanners – sometimes known as LiDAR scanners – are an efficient and accurate way to generate large amounts of positioning data. This makes them particularly useful in building detailed BIM models.

Most tools for gathering location data – total stations, for example – only produce single points of measurement at a given time. While this can be perfectly useful for some surveying jobs, it can be time-consuming if you’re trying to build a sophisticated 3D model of a particular environment.

By contrast, laser scanners work by emitting millions of tiny pulses of light. These pulses bounce off the surrounding environment and return to the scanner. The scanner then uses the time difference – known as Time of Flight (ToF) – to determine how far the pulses have travelled. All this data is then used to generate point cloud models –  incredibly detailed digital representations of the physical environment that can capture everything from the geometry of a building to the texture of its surfaces.

These point cloud models have extensive utility across a range of surveying tasks, including topographic and as-built surveys. They also serve as the foundation for BIM, providing accurate and comprehensive information that can be used to create detailed 3D models of buildings and infrastructure.

Laser scanners have become an indispensable part of the BIM methodology through what’s known as the scan-to-BIM process. This involves taking the point cloud models generated by laser scanners and using them to build or modify highly detailed and accurate digital representations of a given structure.

This process has significant value throughout the full lifecycle of a construction project, from generating the initial model to providing ongoing maintenance and renovation support. The key use cases include:

• Topographic surveys and site mapping. Even prior to design and construction beginning, a BIM model needs a real-world basis – a precise understanding of the actual site conditions, including terrain, elevation, vegetation, and existing structures. Laser scanners efficiently capture this data, creating a detailed digital representation of the site that serves as the foundation for the BIM model.
• Progress monitoring. By comparing regularly captured laser scans to the original BIM model, project managers can visually track construction progress and quickly identify any delays. This allows for early intervention and corrective action, ensuring projects stay on schedule and within budget.
• Quality control. Point cloud data from laser scans can be meticulously compared to the design model to identify any inconsistencies or deviations from the planned specifications. This rigorous quality control process helps ensure that the final construction aligns with the intended design.
• As-built documentation. After construction or renovation, laser scanners create a precise digital record of the final building, capturing every detail and deviation from the original plans. This as-built model becomes an invaluable resource for facility managers, enabling efficient maintenance and informed decision-making for future modifications.

As you can see, the positioning data generated by laser scanners is enormously valuable for BIM. With a consistent source of data, BIM models can be created and updated with confidence, ensuring that they accurately reflect the real-world conditions of the project.

Of course, laser scanners are not the only source of positioning data that can be used to generate or modify BIM models. Other surveying devices, such as total stations, can play an important role in a BIM workflow. And with the advanced automation provided by a robotic total station, this process can be both efficient and extremely precise.

Nevertheless, laser scanners have a number of advantages when it comes to BIM. These include:

• Speed. Laser scanners rapidly capture millions of data points, drastically reducing the time needed to create detailed 3D models compared to traditional methods.
• Accuracy. While total stations are generally more accurate for single-point measurements, laser scanners provide ample accuracy for most BIM applications.
• Detail. The dense point clouds generated by laser scanners capture intricate details and complex geometries that would be difficult, time-consuming, or even impossible to document with traditional methods.
• Flexibility. Laser scanners are versatile tools that can be used in various environments and applications, both indoors and outdoors. They can capture data in challenging conditions, such as low light or adverse weather, making them a reliable and adaptable tool for any BIM project.

The unique strengths of laser scanners – their speed, accuracy, detail, and flexibility – make them an invaluable tool for implementing BIM effectively. However, to get the biggest benefits for your BIM workflow, you need to choose the right laser scanner for your needs. And with so many options available, that’s easier said than done.

Finding the right laser scanner for your BIM needs means balancing a range of priorities and ensuring your new tool is going to fit right in with your existing workflow. Even the most advanced scanner on the market is no use if it doesn’t offer the specific capabilities you need.

When choosing a laser scanner, you’ll need to think about:

• Range. The maximum distance the scanner can accurately measure is crucial for choosing the right tool for your projects. Consider the typical size and scale of the sites you survey to ensure the scanner’s range is adequate.

• Scan rate. This refers to the speed at which the scanner collects data, typically measured in points per second (pps). A higher scan rate translates to faster data collection and increased productivity on-site.

• Battery life. The battery life of the scanner determines how long you can operate it in the field without needing to recharge. Choose a scanner with a battery life that matches your typical workday or project duration to avoid interruptions and downtime.

• Portability. The size and weight of the scanner are important considerations, especially if you need to transport it between sites or work in confined spaces. Consider a lightweight and compact model for ease of use and transportation.

• Software compatibility. Ensure that the scanner’s software is compatible with your existing BIM software. Seamless integration of the point cloud data into your BIM environment is essential for efficient and effective workflows.

This is a lot to balance – and you may benefit from speaking to an expert if you’re not sure where to start. Or read on below for an overview of some of the laser scanners we stock here at SEP.

If you’re looking for a laser scanner that prioritises streamlined operation and ease of use, the Trimble X7 laser scanner should be your top choice. It offers automatic calibration and self-levelling features to ensure you’re getting precision data with limited setup times, and it is fully integrated with Trimble Perspective software for user-friendly point cloud processing and analysis while you’re in the field. But don’t think this focus on simplicity means you’ll be sacrificing detail – it offers a 3D point accuracy of 2.4mm at 10 metres and 6mm at 40 metres.

The Trimble X9 laser scanner is one of the most reliable, durable and efficient all-round laser scanners on the market. If you’re looking for an effective solution for developing high-quality point cloud models at pace, the X9 is a great option. It includes the auto-calibration and self-levelling features of the X7, alongside a range of built-in workflows to provide an intuitive and streamlined scanning experience. And if speed is an issue, the X9 has you covered – it has a scan speed of up to 1000 kHz, offering scan times of less than a minute in some configurations.

If accuracy at pace is essential, the FARO Focus Premium laser scanner is an excellent choice. The Focus Premium can deliver up to 2 million pps, promising to reduce your onsite scanning time by 50% and providing complete scans in less than a minute. And the speed of scanning doesn’t come at the cost of accuracy – the FARO Focus Premium offers a 3D accuracy of 2mm at 10m and 3.5mm at 25m. Additionally, it uses the latest colour camera technology to provide extremely high-resolution colour detail as part of your scans – up to an incredible  266 megapixels of colour information.

If you’re looking for a truly cutting-edge solution that could transform your approach to laser scanning – or even to surveying full stop – then look no further than the CHCNAV RS10 Handheld Laser SLAM Scanner. This innovative device incorporates an advanced GNSS receiver as well as laser scanning and visual Simultaneous Location and Mapping (SLAM) capabilities. By integrating these into a single device, the RS10 offers a revolutionary solution for high-quality reality capture with unmatched speed and accuracy.

Laser scanners play an essential role in the BIM methodology – and that’s not all, of course. They’re enormously versatile devices that offer extensive utility for surveyors, engineers and location professionals of all kinds. But it’s not always easy to find the right laser scanner for your needs. Navigating the competing features, from accuracy and range to battery life and connectivity options, can feel like a real headache.

That’s where SEP comes in. We’ve got over 35 years of experience providing solutions to the engineering, construction and geospatial industries. We don’t just stock a broad range of laser scanners, total stations, GNSS receivers and surveying accessories – we also have an expert team on hand to discuss your needs and help you find the right solution.

So if you’re not sure which laser scanner is right for you, get in touch today.