A building information model (BIM) is an object-oriented building development tool that utilizes 5-D modeling concepts, information technology and software interoperability to design, construct and operate a building project, as well as communicate its details.
BIM is a building development tool that is based on a 3-d model of a building created in an object-oriented (intelligent) modeling software. Once the model is created, it can be used to assist with design, construction and operational tasks; it can also be used as a communication tool. Different uses of BIM may require different software applications to utilize the model, so BIM requires software to be interoperable.
5-D refers to all of the current dimensions of BIM, where the 3rd dimension is considered space, the 4th dimension is considered time and the 5th dimension is considered cost. In the future, the reference will be modified to include 6-D (procurement applications) and 7-D (operational applications).
Most contractors are likely to start using BIM through “partial uses.” The list of partial uses of BIM seems almost infinite. For contractors already using BIM, the list seems to grow daily. For those getting started, the following list represents some of the more common “early” uses that most contractors experience in their experimentation with BIM:
• Scope Clarification
• Partial Trade Coordination
• Collision Detection/Avoidance
• Design Validation
• Construction Sequencing Planning/Phasing Plans/Logistics
• Marketing Presentations
• Options Analysis
• Walk-throughs and Fly-throughs
• Virtual Mock-Ups
• Sight Line Studies
Those who are using BIM will almost universally tell you that the number of new benefits they continue to discover seems endless. Here are a few:
• Assisting with scoping during bidding and purchasing
• Reviewing portions of the scope for analyses such as value engineering
• Coordinating construction sequencing (even if just for two trades)
• Demonstrating project approaches during marketing presentations
• The ability to identify collisions (e.g., identifying ductwork running into structural members).
• The ability to visualize what is to be built in a simulated environment
• Fewer errors and corrections in the field
• Higher reliability of expected field conditions, allowing for opportunity to do more prefabrication of materials offsite, which is usually a higher quality at a lower cost
• The ability to do more “what if” scenarios, such as looking at various sequencing options, site logistics, hoisting alternatives, cost, etc.
• The ability for non-technical people (clients, users, etc.) to visualize the end product
• Fewer callbacks and thus, lower warranty costs
BIM sounds too good to be true.
The paradigm shift: BIM will change the way we work. The typical top-down organizational chart won’t work for BIM because more collaboration is required. This becomes a barrier because old practices die hard.
Technology & software – without industry standards and interoperability, it can be difficult to share building models. This poses a problem because BIM requires collaboration.
Legal issues – there is a perception of increased liability within both the architectural and construction communities that is hindering industry implementation of BIM.
Initially, fears: everyone needs to overcome the legal & risk fears, fear of change, fear of the unknown, etc.
• Software learning curves
• Lack of support from company leadership
• Lack of support from operational staff
• Initial investment costs
There isn’t a single correct answer to this question. However to get an idea of the cost, consider what it takes to implement BIM: software licenses, new hardware, new staff, software training, etc.
Implementing BIM can be expensive; however, keep in mind the major cost (and headache) savings associated with the use of BIM. Not to mention the coming wave of client recognition of bottom-line benefits to them—a fact that will drive BIM capabilities onto the center stage of near future selection criteria for both designers and builders.
The most common question asked is, “Who’s receiving the most benefit and therefore should bear the cost of developing the model?” The growing consensus is that everyone benefits and therefore everyone should bear some of the cost.
As alluded to above, the out-of-pocket expense, even after spreading out the initial technology and training investment, is generally believed to be much less than the cost benefits. Research efforts are underway to prove this point, but until results are in, the biggest challenge is aligning who is receiving the benefit versus who is paying the out-of-pocket expenses. The delivery method, the contract type and the basis of reimbursement may dictate how and to whom the cost benefits will flow.
Make a plan and keep it simple and specific. Focus on tangible objects and avoid scope creep. Avoid implementing on multiple projects before you have learned the lessons of using BIM on one.
Most importantly, don’t oversell BIM or make promises that you can’t keep.
Alright, I’m sold. Now what?
For design and construction firms alike, the first step is the same: pick a first project to test the process on. Both types of firms also need to invest in BIM software, hardware, staff and training.
Design firms can immediately start using the software to develop designs for their prototype project. Unless they are working with a design firm using BIM, construction firms will need to create a 3D model of their pilot project (utilizing a process referred to as a 2D conversion).
Some firms find it helpful to have a BIM consultant assist with training and implementation.
A BIM steering committee can help the team stay focused on their tangible goals. Including senior management and end-uses can be an effective way to gain their buy-in and support.
Because BIM is a collaborative process, the entire project team would ideally be involved: the owner, architect, engineers, consultants, GC/CM and specialty contractors.
However, implementation of BIM doesn’t always happen in an ideal environment, so remember to keep the owner and other non-BIM project participants aware of developments and updates.
Keep in mind that each firm doesn’t need each of these software types:
• Object-oriented 3-D modeling software for creating and manipulating models (i.e. Autodesk Revit or Bentley Microstation)
• Engineering analysis software (i.e. Risa 3D or Tekla Structures)
• Rendering software (i.e. 3D Studio Max)
• Coordination software (i.e. Navisworks or Tekla Structures)
• Estimating software (i.e. Timberline or Graphisoft Constructor)
• Middleware (i.e. Innovaya or Avatech Earth Connector)
• Detailing Software (i.e. Tekla Structures or SDS/2)
Training – from a BIM consultant, software tutorials, coworker or an authorized training center.
According to the AGC Contractor’s Guide to BIM, a 2D conversion is:
A 2D Conversion is the process of taking the traditional CAD files (such as .dwg) and using the attributes necessary to add the third dimension that allows the 2D design to begin taking its 3D form.
The Contractor’s Guide’s definition simplifies the process somewhat; a 2D conversion is not a process that occurs automatically with the click of a “2D Convert” button. A 2D conversion requires that a modeler digitally trace the 2D documents in an object-based modeling program.
Anyone with the right software and training can convert 2D Designs into 3D; most modelers have been able to make remarkable progress with less than a week’s worth of training. The length of time it takes to do a conversion is of course proportional to the amount of experience the modeler has, the complexity of the project and the level of detail of a model. Conversions can be done by the contractor or by a growing number of third-party service providers.
Source: BIMForum. US