What is BIM, and why should you implement it into your architecture, engineering, and survey plans?
BIM, or “Building Information Modeling” is a process of building highly accurate, measurable 3D models that can be very comprehensive, such that they encompass all the specific components needed to virtually build and visualize a project. Existing condition BIMs are produced by utilizing laser scanning data in concert with various modeling software, known as the “Scan-to-BIM” process. These spatially relevant models enable clients to design or work directly on their projects with a 3D capable software package. In fact, these models are so real that potential problems can be worked out before spending excessive time and money on the actual project site.
Laser scanners capture everything in their line-of-sight at a rate of millions of data points per second. This equates to the collection of hundreds of millions of points of data for each field mobilization. This data can be used comprehensively, or partially for individual features or systems. For example, if you scanned an entire room in a warehouse but only wanted to show where the fire suppression features are now, you’d still have the option in the future to locate and extract other items from that same scan, i.e. electrical outlets. The obvious benefit is that this eliminates costly return visits to the site.
Another plus is that scanning offers fast, highly accurate and customizable project deliverables. These are compatible with software such as Leica Cyclone, Autocad/Civil3D, Revit, and others. These scans can result in architectural, survey, and engineering deliverables that can vary depending on what a client is looking for.
Why is BIM useful?
BIM models create a clear, measurable picture of the subject site. So, you can capture and preserve reality as it exists. This scan-to-BIM as-built creates the basis of a living document, easily making changes and adding on without re-scanning. Autodesk Revit, for example, can help a client plan their project, simulate various scenarios, and even take virtual walkthroughs before any work on site is completed. The scan-to-BIM process makes this faster, more comprehensive, and more cost effective than conventional field measurement techniques.
Level of Development
Variations in the Level of Development (LOD) of the entire model or individual instances, families, and systems, their included metadata, and how systems interact with each other can be tailor-fit to each client. Scan-to-BIM models are measurable, modifiable, spatially relevant, digital versions of the subject site. These models allow for instantaneous quantification of objects, space, and fitment, and can be “proofed” before construction. This enables the identification of potential problems early in the design or redesign process.
BIM in Practice
There are 5 main LOD, from LOD 100 to LOD 500. It is notable that it is not a linear effort scale between LOD levels. For example, a LOD 200 BIM requires significantly less effort than a LOD 300. For a survey as-built of existing spaces, LOD 300 and lower is the wisest choice. The higher LOD levels are more appropriate during the design or construction phase of the project. Critical features may be hidden under floors, or inside walls. Platform-critical connection points may be prohibitively expensive to utilize in the model, if they are simply going to be replaced.
Prior to the start of the scan-to-BIM process, it is important to determine what is and what is not to be shown in a model and that the LOD level is clearly spelled out. To find out more information about LOD, we recommend looking at BIMFORUM, a resource that seeks to standardize LODs.
Many building component manufacturers offer “families” and details for use in Revit, free of charge. Families, in this case, refer to the classification of types of objects. Revit puts everything in a hierarchy, much like order, family, genus and species in biology. One example might be doors. A family that would include several “types” of doors, based on size, functionality, material, finish, etc. Another example of a family would be walls. Again, you may have multiple types within the family, like steel stud interior, exterior masonry walls, and regular interior partition walls.
How does Colliers Engineering & Design use Scan-to-BIM?
Recently, Colliers Engineering & Design was contacted by a utility company to provide mapping of their existing facilities so they could add and replace various process mechanical items. Highly accurate scan data and a BIM model enabled the client to completely retrofit this facility with few field visits. This model also became the basis of 4D BIM, (i.e. a model incorporating change over time) to assist with facilities management.
Another client contacted us to scan and create a BIM model incorporating all the steel elements of their warehouse. This model (seen at the beginning of the blog) was used to determine how much space they had and what facilities they could fit into that space for a retrofit of this warehouse. Again, our scan-to-BIM process saved them both time and money that continual field visits would have cost .
The Bottom Line?
Scan-to-BIM is the answer for fast, comprehensive, and cost-effective results. Architects, construction professionals, engineers, and clients can plan, simulate, and have a clear, realistic walk through of their building site before excessive time, money, and effort is put into the site.
This article is part of our Webinar Blog Series. We turned directly to the experts who were excited to share their latest technologies, insights and strategies. If you have questions or would be interested in a Lunch and Learn about any of the topics covered, feel free to reach out to our presenters!