Mechanical contractors positioned to lead BIM process

Building Information Modeling is more than three-dimensional drafting or CAD on steroids; it's a collaborative productivity tool that can get buildings built more efficiently.

Scottsdale, Ariz. — Building Information Modeling is more than three-dimensional drafting or CAD on steroids; it's a collaborative productivity tool that can get buildings built more efficiently. Discussion of BIM was a central focus of the recent Mechanical Contractors Association of America convention here.

University Mechanical & Engineering Contractors, San Diego, turned to BIM as a matter of survival, said President and CEO Steve Shirley. University Mechanical, 88-years-old and a unit of EMCOR Group, was an early adopter of BIM, jumping in back in 2001. The company was on the Construction Users Round Table/Associated General Contractors/American Institute of Architects BIM Interoperability Committee.

University Mechanical faced non-union competition on every job and its wages were 20-40% higher than its non-union competitors, Shirley said. It was not making its labor budgets and needed to restructure and improve productivity.

The initial drivers were standardization of processes, ability to increase fabrication shop volume, and cut rework. BIM was available through affordable software that could integrate with other specialty contractor programs.

BIM is a coordination tool, Shirley said, a method of integration that combines graphics and databases that aggregates all of the data to design, build, operate and maintain a building. University Mechanical holds 10-20 BIM coordination meetings a week to work through conflicts, clarify complex concepts, ensure code compliance and discuss maintenance issues. Requests For Information can be sent on-screen. Every component can have intelligence attached, depending on what is written into the software, so that purchase orders and bills of materials are automatically generated.

There are two BIM models, Shirley explained, an integrated model and a federal model.

In the integrated model, all of the users are on the same software platform. Users can change one part of the plans and it changes across all of the users drawings too. The problems crop up in limits on software capabilities. Additionally, there are legal issues about who owns the model, who can change it, and who is liable for errors.

In the federal model, each contractor takes the architectural and structural drawings, creates its own plans and resubmits them. Each contractor owns its own work product. The only caveat is that the software must be interoperable with everyone else's. One party (perhaps the general contractor although mechanical contractors can make persuasive arguments that they should drive the process) has to monitor and control the BIM process.

BIM is not useful on all projects, Shirley noted, but it's great on complicated jobs such as hospitals and laboratories.

“BIM leaves no place to hide,” Shirley said, because of how much each job has to be planned in advance. Engineers can't brush off conflicts with, “build it the way I drew it.” Contractors can't run out and buy pieces at the wholesaler's counter the next day, because, for example, one manufacturer's 2×2×1 tee may not be exactly the same dimensions as another's 2×2×1 tee.

BIM has a learning curve of about six months. Contractors have to establish firm standards for their detailers. They need electronic document control. Revisions must be tracked; some software has “version control” built in. Contractors may have to create customized databases and libraries of objects. Major manufacturers, such as NIBCO and Watts, are helping by digitalizing their product in formation.

Mechanical can lead the process, Shirley said because they have to be pre-qualified and involved early in the design process. Constructability reviews are conducted concurrent with design.