We have seen an increase in demand for Scan-to-BIM in our recent projects. More and more clients are either making use of a point-cloud scan for their projects or are intrigued by its potential benefits. We therefore wanted to share a brief introduction and outline our approach. Scan-to-BIM is a fairly new digital tool used in the build environment. In simple terms it is the process of taking a 3D laser-scan representation of a space and turning it into a detailed 3D BIM model. The laser collects a group of points with precise coordinates, which represent the scan also known as the point-cloud model. Afterwards, a BIM team can use the scan as a base to create a detailed BIM model. It is a very powerful tool that gives precision and a solid, accurate starting point for a project. It can speed-up the design process and reduce the likeliness of human error when surveying.
A widely recognised use of Scan-to-BIM is in historical restoration and preservation projects. It can create an accurate building data record set and also highlight and prevent potential arising issues with structural integrity, erosion with time etc. The Sagrada Familia in Barcelona is the perfect example. Laser scans allowed for an immense amount of data to be recorded for the iconic church but also provided aid to facilitate the completion of the project. It is important to note that the laser doesn’t affect the fabric of the building, making it a safe choice. Scan-to-BIM can also be used in retrofit projects for exact replicas of the existing, in new construction to verify design intent, quality or compliance with building standards or in facility management for operators to keep track and quantify their assets faster. We are expanding our expertise in retrofitting, training our staff to understand retrofit processes and become trained as retrofit coordinators
The process and how it works
There are three critical steps to Scan-to-BIM:
Firstly, we need to understand what needs to be scanned and why to make best use of the process and determine the best settings. Once the scan area and resolution is decided, the laser, also known as a LiDAR (Light Detection and Ranging) device, rotates 360degrees at high speed to capture the position of all the elements in the space relative to the scanner. In parallel with the laser, a high-resolution camera takes photos of the space. They are used to create a realistic render of the space. This creates a digital footprint of points. The more points collected, the more accurate and detailed the scan becomes.
The second step entails bringing together multiple scans in a specialised software to be processed, cleaned-up and calibrated. It turns ‘raw’ data into a formal, accurate scan and it should only be carried out by a trained professional.
In the final step, the final Point Cloud model is imported into Autodesk Revit or any other BIM software where it is traced and transformed into a fully functional 3D model. Interpreting data sets is a skill, our BIM team has gone through this process multiple times and developed a set of rules to follow for best results. They take time to understand the point-cloud model, setup the overall dimensions like levels, orientation and relevant real-space coordinates and only then split the model into various sections, depending on the scale of the project. The model may encompass architectural features such as curtain walls, windows, interiors, as well as structural and MEP elements. Once done, the 3D model is a digital representation of the existing workset.
The Spar Example: precision, speed & data sets
In 2020, global retail brand SPAR successfully converted 60 gas station convenience stores into express mini marts within just 10 months. They initially tried to convert two stores using conventional methods but were left with delays and budget issues due to inaccurate measurements that led to items not fitting and having to be stripped-out and redone. SPAR decided to try another method using Scan-to-BIM. They applied the process to laser scan all 60 facilities and create digital twins of the premises. They managed to scan one to two stores per day, while having only one person on site to scan. This approach not only saved significant time but also reportedly increased the company’s revenue by nearly 10%. Having an accurate representation of the space, which was not subject to human error, helped reduce the renovation program and thus minimised the amount of time the stores were closed down. Upon project completion, they had amassed a comprehensive dataset for all stores, which now aids in facilities management.*
Source: https://www.autodesk.com/design-make/articles/3d-laser-scanning
Challenges & Benefits
The Scan-to-BIM process can be complex, as it involves managing large quantities of data. For certain projects, additional data sets may be required. For example, in large buildings where only ground floor point clouds are captured, UAV-supported photogrammetry data sets are beneficial for modelling the upper levels and roof. Despite these challenges, the benefits are significant. A well-executed Scan-to-BIM model provides an accurate representation that can expedite the modelling process and generate a comprehensive dataset that benefits all stakeholders
