IQ Spring 2012: The Conference Issue - (Page 31)

desIgN-BuILd doNe BadLy Design Errors and Poor Design Coordination with Subcontractors Floods Project with Problems thIs edItIoN’s ex aMpLe of “design-build done badly” occurred on a fairly straight-forward project. (As always in this column, the client, design-builder and location are kept confidential to protect the guilty.) The $24 million project was a big-box warehouse and distribution center for a foreign retail firm opening in the United States. There was nothing out of the ordinary in the owner’s requirements as compared to similar warehouse facilities. The project progressed smoothly in the early stages, staying nicely within schedule and budget. Quality control on concrete foundation placement, steel erection and building enclosure were on the mark. However the first problem surfaced when the mechanical/electrical/plumbing (MEP) subcontractors ran their distribution lines. The contractor’s specs called for the mechanical and electrical distribution lines across the long rear wall of the building to be run in a racking system between 24 inches and 48 inches above floor surface. But the specs didn’t take into account the eight personnel doors and six overhead delivery doors. The second problem arose just two days later when a heavy rain hit the area. Although the building had a sloped French drain six feet out from the building line, the building still was flooded with about an inch of water. LessoNs LearNed Post-mortem examination revealed the key factors that contributed to this example of design-build done badly. The MEP problem occurred because the design-builder did not convey the design requirements properly to the subcontractors. To keep design costs down, interior elevation and section drawings were limited, with the only rear interior elevation showing a clean wall span (no door openings). MEP subcontractors were not given the rear exterior architectural elevation that would have highlighted the problem. The mechanical and plumbing design was created in single line drawings except for the mechanical rooms, controls, valves and fitting details. Simple MEP elevations with clash resolution from oldfashioned light table drawing checks to modern Building Information Modeling (BIM) models would have identified the conflict. In the case of the drainage and flooding problem, initially, the design-builder thought the silt runoff control caused the clogged French drains. The real cause was a basic design error in the volume of storm water runoff for expected rain events. An experienced civil Professional Engineer (P.E.) should have reviewed the work of a first-year civil designer for quality control. The lessons learned are not complicated, yet they happened to a very well-respected general contractor because he wanted to limit design costs, causing his design partner to cut corners. While the project still finished on time and the owner was happy, the contractor lost money and the design firm had to mend its relationship with the designbuilder because of the design errors. This regular IQ column is devoted to sharing those design-build sins of the past to prevent them from being repeated. Do you have an interesting example of design-build done badly? If so, please contact Patrick A. Burns at patrickburnspe@gmail.com or iq@dbia.org. We will work with you in complete confidentiality to share the lessons you’ve learned with our readers to benefit our industry in a future issue of IQ. By patrick a. Burns, p.E., fSaME, BGen, USaf(r) patrIcK a. “pat” BUrnS, p.E., fSaME, BGEn USaf(r) IS a forMEr v IcE p rE SIDEn t of t hE f EDEr a L contractInG GroUp for MortEnSon conStrUctIon. hE prEvIoUSLY SErvED 35 YEarS In thE aIr forcE In DESIGn, conStrUctIon anD opEratIon of MILItarY BaSES In thE UnItED StatES anD ovErSEaS. dbia.org spring//2012 31 http://www.dbia.org

Table of Contents for the Digital Edition of IQ Spring 2012: The Conference Issue

IQ Spring 2012: The Conference Issue