Let’s face it BIM is here to stay. The process is truly transforming project planning and management. But is it really a useful process? At first blush, you say, “yes.” The data generated from a model can be leveraged into a beneficial visual and informational aid for design and field personnel. Field activities require practical and accurate information from the model to apply to physical construction. So why is it so hard to implement BIM in the field? Could it be that time and accuracy is lost from manual activities? Are teams still making calculations from 2D plans? Are they using old measurement methods? To get to the heart of the matter, this post explores the facts and fiction of BIM.
Let’s explore some BIM FACTS and FICTION:
FACT: BIM brings together all areas of project management for a building’s construction. BIM can incorporate the project’s design, estimated cost, supply chain, materials delivery during construction, schedule sequencing, resource allocation, and post-construction documentation.
FICTION: Architects use BIM to design great buildings and do not need input from a general contractor. As with traditional 2D documents, a general contractor with an experienced VDC/BIM department can provide valuable input as to constructability, clash detection, prefabrication possibilities, and material selection.
FACT: BIM in the field can be enabled through many different technology platforms. There is a wide range of technology platforms (ex: NavisWorks, BIManywhere, Autodesk BIM 360 Glue and 360 Field) to support the specific needs of field personnel for layout, issue tracking, QA/QC, and clash detection.
FICTION: BIM provides clarity between user roles and responsibilities. There are shades of gray when it comes to roles and responsibilities generally because each discipline participates in the planning stage, creates revisions, and provides BIM model input. When the project moves into the field, communication needs to be maintained between detailers, modelers, and field crew to ensure the model is constructible and is being correctly implemented in the field.
FACT: BIM is more than just a 3D building model. The model is a visual reference for working through a building’s design both prior to and during physical construction. The model is also a reference for facility engineers after construction, working in concert with building automation systems.
FICTION: BIM information at everyone’s fingertips reduces the opportunity for claims. If the model is not updated timely or if there is human misinterpretation of the design, issues may ensue with claims of faulty plans.
FACT: Parametric Modeling drives BIM. BIM elements are interconnected. For example, if a wall is moved, elements attached to the wall will also move.
FICTION: BIM is always accurate. The risk of making a change within a BIM model can become an issue on large construction projects where multiple consultants and contractors try to complete changes for their own benefit. When this happens, the team and the project suffer. At a project’s inception, it is important to establish and enforce a quality assurance and quality control [QA/QC] processes for BIM. These practices need to be a outlined within the project’s contractual agreement.
FACT: Stakeholders controlling different disciplines will benefit from other stakeholders as models are progressively improved. In many cases, one change may result in multiple benefits for multiple disciplines. Adversely, one person’s change can also cause problems for everyone else.
FICTION: All project stakeholders have a positive attitude toward BIM. Some stakeholders really benefit while others do not. Therefore, each discipline has a varying level of interest in BIM activities. Some smaller consultants and subcontractors haven’t even embraced BIM yet.
FACT: There are many BIM dimensions besides 3D, 4D, and 5D. Each dimension relates to specific information associated with the model.
FICTION: Every single building component can be modeled. You can, but it is too costly and time consuming to model every single nut and bolt into the model. The team needs to determine the appropriate level of project detail. Not everything should be represented.
FACT: 4D addresses the project’s scheduling requirements, allowing for Just-in-Time delivery of materials. The result is a more efficient construction sequencing and phasing, addressing manufacturing, delivery and on-site transport, material laydown, storage and installation. Ultimately, BIM speeds up construction in the field. It allows you to work out conflicts before you have to deal with them in the field, which can cause costly delays, inefficiencies, and rework.
FICTION: People believe that once the schedule is established it will not change. Unfortunately, BIM cannot predict material delays, required sequencing changes, changes in weather, or owner changes that can affect the schedule over a project’s lifetime.
FACT: 5D addresses the project’s cost. Each building model has an associated estimated cost. In-depth analysis can be performed with the intent to meet project budgets. The team is able to make more accurate predictions on how much needs to be done within any given time to meet construction targets. BIM systems can be linked and mapped with cost database. Also 5D is very useful to assess impacts from changes.
FICTION: 5D considers changes in market price. BIM allows stakeholders to develop an estimate with the most accurate building cost-to-complete; it does not forecast price fluctuations. You still need your crystal ball for that.
FACT: The “as-built” model is part of the hand-off to the owner. Each element in a building has a lifespan; this information is captured in the model. In event of required replacement, the model is a resource for identifying required parts, as well as assuring required work that needs to be performed is done more efficiently.
FICTION: The “as-built” BIM model is 100% accurate. The as-built is not completely precise. There is a minor margin of error when finding the location of a system. As discussed earlier, the model is not representative of all building elements. In effect, you will get to the general location of the system but it may not be accurate down to the inch.
FACT: You need everyone in a “Big Room” to maximize effectiveness. New software platforms, communication tools, faster bandwidth, and cloud sharing allows team members to work out of their own office, but the most efficient way is to work together out of the “Big Room.”
FICTION: Field people can solely work from mobile devices. While mobile devices help with updates, BIM requires a range of collaborative forums. Whether it is from a team exchange in a “Big BIM Room” or an update via mobile device, the model is receiving information from a range of different touch points.
FACT: BIM models can be used in manufacturing building components. Structural steel fabricators as well as HVAC ductwork fabricators link to the model to their shop production lines.
FICTION: BIM can be used to prefabricate all building components. In time we will be able to prefabricate building systems on a greater level. Today, a lot of designers, builders, and tradespeople are working together to develop new methods for prefabrication, which will ultimately result in construction efficiencies.
As you can see, BIM is easily replacing 2D drawings. After you’ve read through this article, did we miss anything? Please share your FACT and FICTION discussions with us in the comments section.