Continuing our exploration of trending technologies in construction, Today I want to address Building Information Modeling (BIM) Technology.
BIM Technology has been around for quite some time. As early as 1985 Architects and Engineers have had access to digital tools that allow BIM modeling. The earliest software for this was a lesser known tool called Pro/ENEGINEER (now known as Creo).
Now let’s be clear, virtual modeling is not the same as renderings.
Architects have been producing renderings of buildings even before the prominence of computers. Back then, we relied on artistic skill and formal methods for developing perspective drawings.
When computers became the standard tool for drawing, renderings evolved from hand drawn perspective drawings into digital representations of space. These early digital renderings were nothing more than digital planes arranged in a way to represent a building.
Virtual modeling such as can be achieved with BIM is a far more advanced concept.
BIM models are digitized versions of the built environment. Each part of a BIM model has properties such as; weight, density, and mass. These digital elements come together with all the same properties of the real world to virtually build the building.
Today the leading BIM tool is REVIT. REVIT users are some of the most sought after drafts people in the industry and almost every major Architecture practice offers BIM modeling.
Benefits of BIM
So why would anyone want to create a digital model of their building?
A recent article from BIMToday (a publication from Bentley) reveals the results of a survey of 602 architects, engineers, and construction professionals who were asked what they thought were the biggest benefits of BIM.
Coordination and Clash Detection
Seventy-six (76) percent of respondents said that the main benefit of BIM modelling was that it improved coordination and allowed for clash detection.
Clash detection simply means that if a pipe or a duct is running through a beam or a column, the software can detect this and the design can be revised to correct the problem. This feature is unique to BIM models and cannot be done on any other form of Computer Aided Drafting (CAD) Software.
Without BIM this work is done by the trade contractor in the form of a shop drawing. The way this is done without BIM is that the plumber or the HVAC contractor physically traces out the path of the pipe or duct ensuring that the path is clear. The contractor then sketches out the path and submits a shop drawing for review and approval.
This is a common and accepted practice in most projects, but it can be avoided using BIM.
According to the survey, the second most common benefits of BIM is that it positively enhances the design process. Seventy-two (72) percent of respondents made this claim.
I find this to be a subjective and intangible benefit so I wont comment any further other than to say that Frank Lloyd Wright and Le Corbusier did not have BIM and look what they were able to accomplish!
The third benefit described by respondents was that BIM modelling reduces errors by eliminating duplication of work. This is so because the model facilitates traditional drawings such as sections and elevations without the need to create a new drawing. As you build the model you essential create every possible view. Cutting sections through the model or showing an elevation is a matter of simply creating a view that shows the image you want.
This is a great feature of a BIM model and does eliminate the potential for mistakes.
The fourth benefit of BIM according to 66% of respondents is that it improves costs estimates. This is also a true statement and an excellent use of BIM. The way BIM improves cost estimating is that it facilitates doing takes-offs (or estimates) of materials. In non-BIM projects materials are estimated by counting and measuring each section of the project by hand.
This is another great feature of BIM models and another excellent use case for BIM.
What’s Wrong with BIM
Undoubtedly due to Bentley’s bias (they sell the second most popular BIM software), their article stops short of sharing any reasons for not using BIM.
Lucky for you, I’m here to remedy that.
One of the reasons why a firm might not have BIM is that it is very expensive software. A single license subscription of Revit costs $2300 while a single license of AutoCaD is $1200.
In addition, there are far more competent 2D CAD operators in the market than there are competent BIM operators. This means that BIM operators are more in demand and command higher salaries.
These two factors alone make it difficult for a small Architect or Engineering practice to offer BIM.
Such an investment would increase the firms overhead costs (see my previous article on overhead costs) and make the firm less cost competitive.
The Whole Team Needs It
Another problem with BIM is that it is only effective when it is used by the entire project team.
Consider how an Architect using BIM would work with an Engineer that is not using BIM. The Architect would build the BIM model and then convert the drawings down to 2D CAD files to share with the Engineer. This completely eliminates the number one, and number four reasons for using BIM.
Clash detection does not work unless all of the building systems are modeled in BIM and doing take-off from BIM only works under the same conditions.
This effectively limits the Architect’s pool of potential Engineering firms and because each firm has to cover the added cost of software and personnel, the entire design cost will be higher.
It Takes Longer
The third problem with BIM modeling is that the up-front modeling and design period takes approximately 15% longer than design periods in 2D CAD projects.
This prolongs the Schematic design period causing the design progress to move more slowly.
This is so because building a model in BIM requires you to effectively build the building in the same way that it would be built in real life. As you might imagine this takes significantly longer than sketching and drawings lines in a traditional 2D floor plan.
BIM practitioners would argue that you make up some of that time in Design Development phase, but I’m not aware of any case studies that validate that.
Should You Use BIM
So with all of this in mind, the question is, Should you use BIM?
The answer is, “It depends”!
If you have complex projects that require a great deal of coordination, such as a manufacturing project with multiple building systems that must be tied together, I think BIM is a great way to go.
I’ll qualify that with the message that this works ONLY if the entire design team is modeling their systems. Otherwise, don’t waste your time or money.
For simpler projects such as office spaces and certainly in residential projects there simply is not enough of a case for the additional cost and time that a BIM model adds. For projects such as these the industry is mature enough in their processes that they can easily handle field coordination and manual estimating.
Building Information Modeling is a great technology. It is the conduit for other emerging technologies like 3D Printing and Robotics. One day all projects will be done in BIM and the market will be saturated with BIM operators. In the meantime, we need to remain prudent. We don’t need a sledgehammer to drive a single nail. Take stock of each project and determine whether the additional time and cost are necessary.
For projects where BIM makes sense, be sure to require the entire team to use BIM. This is essential for realizing the value of this great technology.
What about you? Are you using BIM on every project? What benefits have you realized with BIM? Tell me your stories.
Thanks for reading. If you enjoyed this content, please feel free to browse my previous articles and please like, share, comment, and subscribe. This helps promote my content and is greatly appreciated.