D-B and IPD My Way -- Part 1
Some project delivery takes a village — and that’s a good thing.
Over the years of designing and building HVAC infrastructure, I’ve been fortunate to be able to complete the projects via integrated project delivery (IPD) and design-build (D-B), in addition to design-bid-build (DBB) and construction management (CM).
Why is this being fortunate? Well, unlike DBB (and to some extent CM), IPD and DB require full team participation (FTP). In my world of design and construction, FTP was mandated to the owner, O&M department, trade contractors, TAB company, design team, and commissioning firm if we were going to go this route of project delivery. In fact, before commissioning became a much-needed task, our FTP approach inherently provided our own commissioning process because there was ownership by all. Consensus and not any one individual made the team decisions. As we scoped out the design intent based on what the owner needed (e.g., replace antiquated chillers), we did so via team estimating within our FTP process.
When a building owner wanted to use IPD or D-B project delivery to complete their building program, I would outline the proposal process as follows.
Step 1: Meet with the owner’s in-house project manager, owner representative (if requested), facility O&M manager, FTP facilitator (that would be me), a major HVAC contractor with an in-house service department, estimating department, and preferably in-house design engineers with mechanical-electrical coordination experience and/or prequalified HVAC, and electrical design engineers to kickoff this initial open discussion on IPD project delivery. An IPD/DB mission statement would be written, agreed upon, and signed by all participants.
Step 2: With the same FTP members, the second meeting would now bring in prequalified electrical, plumbing, structural trade contractors, utility company energy representative, and structural engineer to present the IPD/DB initiative and to have these new team members add their signatures to the mission statement. The second part of this meeting would be an open discussion on designing, building, and commissioning of the building program, with assignments agreed upon for each major task (e.g., drafting would be completed by the trade contractors responsible for fabricating pipe, sheet metal, electrical). Note: each meeting would have meeting minutes that had to be completed within 24 hours and distributed with action items, assignments, and due dates.
Step 3: With the HVAC design engineer leading the conceptual design, an itemized checklist of preliminary equipment selections and material specification along with system flow diagrams would be produced. The lead estimator would then facilitate the FTP process in a “team estimating” exercise to firm up the conceptual scope of work into a final scope of work, a.k.a. an IPD concept book along with a project schedule. Note: In the past I have said, “As an experienced design engineer I can produce the very best chilled water system design, BUT I believe an experienced pipe fitter can make my design even better based on his years of experience installing chilled water systems.” This is why “team estimating” is so important and shouldn’t be left up to just the estimator. FTP would always bring a better result when not left to individuals.
Step 4: In sync with the development of the IPD/DB concept book that now included the system flow diagrams, we move on to the proposed sequence of operation. This is based on input from the O&M staff and the design engineer, documenting how they foresee this energy retrofit chiller plant. The sequence of operation is based on a load profile using past chilled water load, peak demands, and future load and demand. Integral to the new design would be the incorporation of ASHRAE Guideline 22-2012, Instrumentation for Monitoring Central Chilled-Water Plant Efficiency.
Step 5: With a very good understanding of the design intent along with estimated energy performance savings, a very good (if not final) estimate, and a project timeline, the FTP’s HVAC contractor could now pre-purchase the new chillers, associated pumps, and VFDs. With the equipment buy-out probably being a little better than estimated, any savings would go into a contingency fund. That fund’s distribution of money would be determined later should additional cost arise or possibly to enhance the installation via a wishlist.
See next month’s column for part two of “DB and IPD My Way” as I go through the remaining stages of the full team participation.