Building Information Modeling (BIM) 101

Aug 10, 2017

BIM Image

What It Is & Why Contractors Should Care

BIM is no longer just for Architects and Engineers.  Based on the Associated General Contractors (AGC) of America’s 2017 Construction Hiring and Business Outlook, BIM usage among contractors is expanding significantly.  In fact, many contractors are highlighting their use of BIM in order to stand out to project owners and attract more business.

We’ve covered the topic briefly in the past with our article about Making BIM Work for Builders. Now we’re going to take a deeper dive so you fully understand what BIM is and why you, as a contractor or construction firm, should care.

What is BIM?

A building information model (BIM) is a digital representation of a building or infrastructure made up of objects – electronic versions of building components, such as walls, doors, and windows – that can contain dimensions and product information. An object can also be a resource or process, such as a laborer, a piece of equipment, a temporary structure, or pouring concrete.

With BIM, objects can act intelligently in relationship to other objects. Consider, for example, the rules that construction superintendents take for granted when deciding on the positioning of a door and a light switch. BIM can incorporate these same rules so that, for example, when a door in the model is moved along a wall, the swing of the door and the location of the light switch move in relationship to each other.

More than just the digital model or software used to create it, BIM is an entire model-based process in which building team members share information and collaborate to more efficiently plan, design, construct, and manage buildings and infrastructure.

For contractors, BIM is a way to work out the kinks in a project’s design and construction before crews even set foot onto the jobsite. It also allows a company to collect and later share as-built information with customers that can be used in future facility management and maintenance.

The Different Dimensions of BIM

The main BIM processes are often described as different dimensions – 3D, 4D, 5D, and 6D BIM.  With each dimension, BIM gets closer to its vision of estab­lishing a basis for improved decision-making and problem-solving throughout the building life cycle.

3D – The process most associated with BIM today is 3D design, which offers many benefits over 2D drawings. Project stake­holders can better visualize and inspect a project with more realistic representations of the building or infrastructure. An estimator can see whether a wall is slanted, where there are soffits, and other details that aren’t apparent on 2D plans. This allows the estimator to better understand a project’s complexity and create a more accurate estimate.

Clashes can also be more easily identified and resolved. For instance, BIM processes can help detect pipework running through a steel beam (a hard clash) or a safety issue for workers (a soft clash).

Catching these types of issues during the design phase can substantially reduce total project cost; in fact, a clash found during construction can cost anywhere from thousands to tens of thousands of dollars – unexpected costs to consider from an accounting perspective.

4D – When timelines are applied to models, it’s known as 4D BIM. This allows construction planners to run simulations to assess how proposed design features will impact the schedule and workflow. With 4D BIM, planners can determine appropriate resource scheduling, identify potential bottlenecks, develop phasing plans, communicate and track milestones, and find opportunities to improve the schedule overall.

4D BIM models are especially helpful in exploring space and sequencing requirements. The best placement for material delivery, temporary facilities, and equipment and assembly areas can all be evaluated and determined for each phase of the construction process.

5D – 5D BIM, also known as model-based estimating, brings together design and scheduling processes with the cost element of construction.

Using estimating tools that integrate with BIM, estimators can more quickly provide owners and others on the building team with the cost impact of different design and schedule scenarios. Cost-saving strategies can be explored and detailed cost risk assessments conducted in significantly less time. As the design progresses and changes are made to the model, the estimate can be easily – if not automatically – updated to assure everything stays within target costs.

5D BIM provides a more sophisticated cost analysis. For example, costs can be linked with the master schedule for such visualizations as showing the cash flow of a project. Or, sustainable design strategies can be evaluated from a cost perspective, including projecting energy savings for owners in the future.

Adding the cost component to BIM can have a large impact. In fact, the McKinsey Institute lists 5D BIM as one of the “five big ideas” that can help the construction industry transform itself over the next five years.

6D – BIM doesn’t stop once construction is complete; 6D BIM kicks in during the operations and maintenance of the build­ing. Using as-built information gathered from the design and construction process – as well as updated details from ongo­ing maintenance – facility managers can use 6D BIM to sup­port decision-making throughout a facility’s operations cycle.

Consider, for example, all the equipment installed in a build­ing. Data available through a model can include such details as equipment manufacturer, installation date, expected lifes­pan, and recommended maintenance schedule and operation guidelines. With this type of information, facility managers can predict anticipated maintenance expenses far into the future. It also allows for more proactive maintenance, which is less expensive and not as disruptive to building occupants.

When renovation is needed, 6D BIM also provides valuable information. Owners can have access to drawings and infor­mation showing exactly how a facility was constructed. So, when renovation crews tear into a wall, they already know what’s behind it, saving time and money on renovations.

The Business Impact

Now that we know how BIM works, let’s answer the most important question that can be asked … does it really make a measurable difference for construction businesses?

A 2016 BIM study conducted by Dodge Data and Analytics provides some insight into how contractors and construction managers view BIM’s impact on their work:

  • 70% reported at least a 5% decrease in requests for information (RFIs) during construction, indicating improved communication.
  • Approximately 50% saw at least a 5% reduction in material waste, schedules, and final construction costs.
  • 43% of trade contractors, 26% of GCs, and 25% of construction managers saw at least a 5% decrease in reportable safety incidents.

BIM can also lead to more business opportunities. Many federal agencies are moving toward requiring BIM on their building projects. State and local governments are also requesting BIM (e.g., Wisconsin and Texas have adopted BIM deliverable standards).

The Challenges of BIM

BIM has made great strides, especially from a design and engineering standpoint. However, it is still very much in its infancy when it comes to passing information “downstream” to other parties that use the model.

Model authors are typically designers who don’t necessarily know what information other building team members may need. For example, estimators using a 3D model to take off quantities often still need to refer to 2D drawings because such details as floor and wall finishes are typically missing from the 3D model.

Kevin Miller, a professor of construction management at Brigham Young University who specializes in estimating from BIM models, explains that “We’re going through a transitional period where some designers are advanced at using BIM and some are still learning it, so the amount of information included in a model can vary greatly.”

Better communication is still needed so downstream users – such as estimators –understand the usability and limitations of the models they are receiving. But strides are being made as more companies are using BIM and better standards are developed.

New technology is also helping to bridge the gap for estimators and others when information is not available from a model. For example, some takeoff systems will allow estimators to switch between 3D models and 2D electronic plans so that they have all the necessary information for producing estimates more quickly while also taking advantage of the visualization and collaboration benefits of BIM.

The Future of BIM

The future of BIM promises many advances and wider adoption by ALL phases of a project from concept to construction. In fact, some contractors are already combining virtual reality (VR) with models to create more real-life experiences and virtual walkthroughs of various building design options. BIM is almost certain – destined maybe – to become a major factor in the construction industry.

Need help putting BIM to work for your construction business?  Click below to get in touch and talk to one of our construction industry experts at Accordant Company.

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