What is a Building Information Model (BIM Model) & How are They Used?
A Building Information Model is a 3D digital representation of a building’s features and measurements that is used by everyone from real estate developers to architects and building designers to construction contractors to plot, plan, design, prefabricate elements offsite, and collaborate on any building, retooling, or renovation project before anyone even breaks ground.
Here’s the NIBS (The National Institute of Building Sciences) definition of a BIM model: “A BIM is a digital representation of physical and functional characteristics of a facility. As such it serves as a shared knowledge resource for information about a facility forming a reliable basis for decisions during its lifecycle from inception onward.”
Standards for BIM Models in Design
The construction, engineering, and architecture industry has seen a recent update from NIBS (The National Institute of Building Sciences) regarding their ongoing initiative to create a nationwide standard for BIM models in design.
September 2022 marks the third update to the proposed National BIM Standard, for which NIBS chartered its BIM Council in 2005. Now known as the Building Smart Alliance, they have been working for more than a decade to create and reach consensus on a national standard, and their first nationwide BIM standards release occurred in 2007. The new standards just issued by NIBS are known as NBIMS-US™ V3 and are included in a 3,100-page document laying out the rationale behind the collaborative effort to create the standards and how they can be effectively implemented.
Adopting New Technology in Data Capture for BIM Modeling
It is now possible, and even desirable, for as-built, existing structural elements to be measured and captured by 3D laser scanning, which utilizes LiDAR (light detection and ranging) at the rate of 2 million data points per second to provide structural features and measurements with millimeter accuracy. That data, organized as a point cloud, is then sent to CAD designers BIM Managers, Virtual Design Construction teams (VDCs), and technicians to fabricate the digital model with similar accuracy and attention to detail.
However, as pointed out in a recent Yahoo News article, the architecture, engineering and construction industries have been slow to embrace digitalization for construction projects. In many cases, architects and builders rely on manual measurements which can be as much as a full foot off. BIM models created with those measurements make clash detection/avoidance and off-site prefabrication difficult. Manual measuring for BIM can cause huge cost overruns, change orders, and lost time on the job when the data proves to be inaccurate.
“A critical issue in the U.S. construction industry is its low level of digitalization, which prevents it from transforming lifecycle work processes to be more efficient, less expensive, more resilient, and safer to build and maintain.” – Yahoo News
It makes sense, given the vast differences in modeling practices across the construction and design disciplines, to find a common standardization. Which is why in June of this year, NIBS brought in AEC specialist Johnny Fortune to oversee their national BIM initiative.
Additionally, the Building Smart Alliance cites the statistic that a mere 1% improvement in productivity in the architecture and construction-related industries has been achieved in the last 20 years, although the technology exists to vastly improve the timeliness, cost-effectiveness, and safety on construction and renovation jobsites.
Which is why they brought together 40 industry leaders to explore the subject and collaborate on best practices for version 3.
Where Does 3D Laser Scanning Fit In?
LiDAR News, a leading industry publication, had this to say about the upcoming V3 standards in February of 2022:
“The transformation in the building industry fostered by the evolution from use of analog drawings and text to the use of digital electronic Building Information Modeling (BIM) is comparable to the transformation that has already occurred in the aircraft, microprocessor, and automotive industries. Early definitions, which assert that BIM is simply a 3D model of a facility, are far from the truth and do not adequately communicate the potential of digital, object-based, interoperable building information modeling processes and tools and modern communications methods.”
There seems to be a persistent omission from NIBS massive standardization initiative: The use of 3D laser scanning technology. This omission is confounding, considering its popularity and use for structural measurements and building feature capture across the architectural, construction, and engineering spaces.
3D laser scanning with LiDAR is considered the most efficient, effective, and accurate measuring tool available to architects and designers because it can reduce measuring times down to a few hours, and instantly capture data and photogrammetry, so that CAD designers and Autodesk technicians can easily rectify the point cloud and images to provide an accurate and immediately accessible BIM model, along with drawings, maps, and even complete walkthrough and flythrough tours of the BIM.
GPRS' Director of Laser Scanning, Nate Baker, had this to say about the importance of 3D laser scanning in the BIM world and why standardization matters. “Laser scanning is typically the basis or starting point for an architect, engineer, GC, etc., when they don’t have good or existing drawings. So, we need to come up with a standard way of communicating expectations for all stakeholders.”
Baker voiced his opinion on the seeming continued omission.
“I think [standardization] is great… but it doesn’t really address laser scanning. For example, an LOD 400 model [a type of BIM] should include window internal mechanisms in the model by definition. With laser scanning, we are limited to line of sight, so we are not able to see those features and therefore cannot capture them in our data or model them. The USIBD has tried to fill this gap, but even they focus more on defining accuracy and less on defining what we will be capturing and how we will be modeling it.”
The organization Baker referred to, USIBD, is the U.S. Institute of Building Documentation, and fills a role adjacent to that of NIBS: to “establish standards, guidelines, and best practices to foster excellence in productivity, quality and safety of the documentation process.” It does not, however, specifically address 3D laser scanning’s role in data capture for BIM, although it is trying to bridge that gap.
When asked if he believes NIBS will succeed in its third BIM standardization attempt, Baker replied, “Yes, I do. There is a huge need for it, but I do wish they specifically addressed laser scanning. Laser scanning is a huge part of capturing as-built/as-is conditions, and so I think it should not be overlooked.”
Scan-to-BIM modeling services, like those provided by the Mapping & Modeling Team, are constructed with a wide range of software, but the goal is the same: to construct a true digital twin of the existing as-built structures to streamline data sharing, coordination, and management on the project.
Who is GPRS?
GPRS is a leading provider of 3D laser scanning services in the U.S., delivering accurate as-builts, point clouds, 2D CAD drawings, and 3D BIM models of architectural, structural, and MEP system layout and dimensions for existing buildings, facilities, and sites.
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