Kari Moosmann
Kari Moosmann
This model of a cast-in-place garage allows a concrete subcontractor to estimate volumes, extract rebar takeoffs, and produce accurate lift drawings.
TEKLA This model of a cast-in-place garage allows a concrete subcontractor to estimate volumes, extract rebar takeoffs, and produce accurate lift drawings.

Building Information Modeling (BIM) is more than a fancy 3-D CAD program. Typically it is described as real-time, dynamic building modeling software that increases productivity in building design and construction. It's a powerful workplace management tool that allows the construction process to be monitored from design, through preconstruction, and to the final construction phase. Along the way changes are incorporated, clashes s detected, and the entire schedule monitored.

BIM includes spatial relationships, geographic c information, quantities of building materials, and manufacturers's details of the building components. BIM can be used to demonstrate the entire processes of construction and facility operation.

Errors can decrease greatly when using BIM by allowing the use of conflict (or clash) detection where the computer actually informs contractors about parts of the building that interfere with one another. This can be done using detailed computer visualization of each part in relation to the total building. Then, any change made is updated in every drawing and view.


Most BIM systems are geared toward the front-end—mostly for architects and engineers involved in the design. Tekla Corp., Kennesaw, Ga., concentrates on the construction end. Its Construction Management module can be used to manage construction projects from conceptual design to preconstruction planning to ongoing site management. The Tekla Structures system has enabled the use of BIM to expand to concrete contractors and general contractors. “Tekla focuses on the people who are physically building the building,” says Alistar Wells, Tekla's concrete segment manager. “We have the complete construction workflow.” Different modules of the system allow it to be tailored for those working on the project—from the general contractor to the various subcontractors.

But using BIM also requires accommodating those who are not on the system. In an industry where 99% of contractors still need drawings, Tekla Structures allows you to print a snapshot of a view, says Wells, accommodating the needs of all.

Another important feature of BIM is user friendliness. Risa Technologies, Foothill Ranch, Calif., combines its ease of use with advanced analysis capabilities in its BIM system. Risa's structural analysis and design software is also modular, analysis with the different elements applying to the various type of construction, such as floor, foundation, or tower.

Advantages of BIM are many, including better visualization, improved productivity, and coordination of construction documents. Information can be linked, such as material vendors, location of details, and quantities required. Results of using BIM include increased speed of delivery and reduced costs.

Industry issues

One of the issues currently under discussion is the Industry Foundation Class (IFC). The IFC format was developed originally to promote interoperability between software in the industry. It is still a work in progress as industry committees are determining the best coding system for all elements. Associations such as the American Concrete Institute and the Concrete Reinforcing Steel Institute (CRSI) are actively involved in discussions of how to best integrate the industry. CRSI, in particular, has been exploring standards and coding for rebar to ensure uniformity in usage and design.

Wells finds that BIM finally is being recognized by the cast-in-place industry. BIM was quicker to take hold by those working with precast and steel, he says. Other BIM software exists on the market that may be more design oriented, but should be considered. Some of these products include: Bentley Architecture, Exton, Pa.; Graphisoft ArchiCAD, Newton, Mass.; VectorWorks ARCHITECT, Columbia, Md.; Vico Software, Boulder, Colo.; and Autodesk's Revit, NavisWorks, and Architectural Desktop, San Rafael, Calif.