An old TV commercial for Reese’s Peanut Butter Cups showed two people discussing what was better: One loved peanut butter and the other person prefered chocolate. Somehow the peanut butter and chocolate got mixed together and they both agreed the end result was even better.

When building information modeling and lean were first introduced in construction several years ago, there was some discussion about which was better. Like the peanut butter and chocolate candies, many HVAC construction contractors have found that doing both is better. Some contractors still struggle to do either effectively.

BIM is the process of generating and managing building data during the lifecycle of a building. BIM uses three-dimensional, real-time, dynamic building modeling software to increase productivity in building design, construction and maintenance. BIM includes building geometry, spatial relationships, geographic information, and quantities and properties of building components. Today’s contractor also uses BIM to do four-dimensional simulations to see how part or all of the facility is intended to be built.


When first introduced several years ago, before the job was built, the designers, engineers, contractor and subcontractors used BIM software to create an interference-free model. The trades would know exactly what is to be installed and where. Subcontractors were able to commit to completing work in an area because they knew they could do it without interference from other trades.

When not using BIM, any interference resulted in meetings to work out problems. This stopped project flow and often resulted in the workers going to another area until the interference was resolved. Contractors had to have additional materials available on the site in case the crew had to leave the planned work area. Interruptions caused wasted time and usually extended the job.

BIM and lean have matured over the last few years. George Zettel, a lean construction manager at New York-based Turner Construction Co., said he now sees the clash-identification effort itself as waste.


“Holding long clash-detection meetings and counting with pride that we found and fixed 400 ‘clashes’ like we did from 2003 to 2008, is no longer a best practice,” Zettel said. “Clash is waste and a sign that the design of the systems was not integrated and coordinated properly from day one. Now there is waste of re-engineering, redesign and potentially several more ‘loop-backs’ to get the systems to fit and work together.”

One of the main lean tools is the Last Planner System or LPS. The “last planner’ is the field construction supervisor who assigns work to the crews. The system consists of developing and using several key plans along with weekly meetings, daily “huddles” and constraints measurement. It is a very effective tool when applied correctly.

Many HVAC construction projects now use BIM and LPS. These jobs are showing greater productivity improvements.

“BIM and lean are completely compatible,” Zettel said. “Most practitioners understand BIM as a process and tool for applying two lean fundamental principles: add more customer value and reduce waste. We see significant reduction of time and labor hours, especially in alternative delivery style projects like design-build and integrated project delivery. We also see BIM and lean principles applied to a lesser degree, yet still very valuable in lump-sum contracts, helping both public works and private owners. Collaborative design between engineers and trade contractors ensure discussions about performance, quality, and target costs are clear. Large elements of building systems like main ductwork, large gravity piping, and large electrical mains, are sized and located once in a well-coordinated manner among other fixed building systems. The components are designed without clash from day one.”

Obsolete work

Eliminating redesign and rework has always been a challenge in the construction industry. Through BIM-related software, there are now several applications that check for some typical design rework issues, such as code compliance.

BIM and technology advancements have also reduced the mountains of paper copies of obsolete drawings and frequently trips to and from the jobsite trailer to view the updated drawings. Many jobs now have computerized “smart” screens located at various parts of the construction area. The trades can use these large screens to view detailed current drawings and upload photographs of completed work.

Matt Cramer, president of Dee Cramer Inc., a mechanical HVAC market contractor based in Holly, Mich., said building information modeling and lean construction are complementary.

“In my opinion BIM, as a broad term — there are many different definitions — is a significant tool that enables lean to happen,” he said. “In fact, for any collaborative — like IPD — projects, BIM is a mandatory. On projects like those, collaboration is the key to make it all work. BIM allows info to be shared and used at the right time by the right person, which allows lean construction and design to come together.”

Both needed

Cramer said he believes you cannot truly do lean construction without using BIM, too.

He sees that problems using BIM and lean are mostly dealing with different levels of understanding of and experience.

Turner Construction’s Zettel said he sometimes experiences difficulties in applying BIM and lean. In some cases, upper management really needs a better understanding what waste is, as lean defines it. A “big picture” view of “waste” is often lacking, he said.

Cramer said another “major challenge is the lack of available software and management solutions for facilities management that use BIM. If there were more available — and more affordable — for the ‘average Joe’ owner, I believe BIM adoption would be more widespread.”

The future changes each day as employees seize new opportunities to reduce waste, many by applying ever-improving technology. One such possibility could be for BIM software to track change orders, request for information, punch lists, and “as-builts” to create a database to see trends and rework patterns. This could, if used properly, accelerate learning and prevent future rework. No one can remember all past errors

Both BIM and LPS improve how projects are planned and executed. They go together like peanut butter and chocolate.

 For reprints of this article, contact Renee Schuett at (248) 786-1661 or email