Design, Coordinate, Fabricate
Prefabrication is one of the main factors for subcontractors to adopt a BIM workflow. The old saying “measure twice, cut once” is a great example of why contractors are coordinating real LOD 400 content. The assurance that the content you put in your model for design, coordination, and prefabrication is also going to install in the field without second guessing is remarkable.
Improving productivity is reported as the top driver for using prefabrication/modularization by construction managers, general contractors, and design-builders. (McGraw Hill 2012).
As you can see in Figure 1, contractors are using the same Revit MEP model from design to construction. Instead of going from one platform to another, contractors use the design data from the beginning of the project to the end. The saying over the years has changed to “design, coordinate, fabricate.”
Figure 1
Plumbing Prefabrication
Al Beckes from J&S Mechanical Contractors worked directly with Neil Spencer from Van Boerum & Frank Associates, Inc. on the Eccles Performing Arts Center. The engineer had very specific mat footings (Figure 2) for this project. The reason for the s-traps on all the floor receptacles was that the design engineer wanted to address the challenges posed by a job-wide structural mat-footing that was several feet thick. The mat-footing depth is such that the design option is to either make an s-trap or be forced to exceed the maximum tailpiece length. In the end, the city reviewers chose to allow the s-trap on a combination waste and vent system rather than to exceed the maximum tailpiece length.
Figure 2
The design decision was made quickly to use floor drains and ensure the s-traps would fit in the specified determined pocket. Since both Al and the engineer were using the same software platform, Autodesk® Revit® MEP, they could collaborate real time in the same model.
No need to spend additional time exporting out of Revit to AutoCAD®. Al could use the original Revit design from the engineer while using SysQue® to add the LOD 400 level content that was required to ensure the model could be fabricated and installed correctly.
Al utilized Trimble MEP on this project to locate all risers and elevations for his underground plumbing. Al reports that he will continue to use this process for hanger layout above ceiling for each floor. This process allows the field to put away the tape measures and keep the same accuracy and precision that comes from the LOD 400 model.
Figure 3
“J&S Mechanical Contractors is now fully transitioned to Revit. I always kept Revit at a distance after using AutoCAD for so long, and only using and cussing Revit when I had to. We’ve taken the plunge on our two most recent projects, and though still cussing, it is less and less and I am liking Revit more and more. I sent out our first runs of fabrication in Revit using SysQue (the reason we made the jump to Revit) and I can definitely see our move saving us time as the field is now up to speed with Trimble and using it for layout of our prefabricated underground. In short (I never thought I’d say this), Revit rocks. Also, one thing I’ve learned is to quit trying to make Revit AutoCAD. The best thing I ever did was to quit dealing in equivalencies and start thinking in Revit rather than trying to translate it into AutoCAD.” (Al Beckes, August 27, 2014) Add fellow Revit Users as LinkedIn connections http://lnkd.in/dDjWAw4
Piping Prefabrication
Ryan Joyce, BIM Services Director at PACE Collaborative, says, “The detailed data content available in SysQue far exceeded our expectations. SysQue allows us to quickly model mechanical piping and plumbing to LOD 400 directly in native Revit MEP, and the spooling documentation even includes pipe cut lengths in isometric sheet views. It saves us so much time and money by using SysQue. Each Revit family from Building-Data contains a link to the manufacturers’ PDF cut sheet. All of our models’ mechanical pipe valves and fittings now include bills of material within the family, with material costs and labor rates per each size, and item bubbles identifying each component to support shop prefabrication. It’s incredible.”
Figure 4
Figure 5
Project: Utility Building Renovation on Wallops Island for the Army Corp of Engineers
General Contractor: MEB Contractors
Architect: Ivy Architectural Innovations
3,800 sq ft central plant with 4 cooling towers, 4 chillers, 10 base mounted end suction pumps, 2 inline centrifugal pumps, and 1 heat exchanger.
