Understatement of the New Year: Healthcare design and construction aren't what they used to be. Modern project delivery methods involving building information modeling (BIM) are game-changers, and trends toward sustainable design and new space allocations are imposing new demands on the field. Nowhere is this more evident than in MEP engineering (mechanicals/electrical/plumbing). In fact, BIM grew out of its early applications to MEP, focusing clash detection, but architects and engineers designing healthcare facilities report that it's gone far beyond that.
“BIM has become mainstream, with new opportunities arising all the time,” says Kurtis Young, PE, at Walter P. Moore and Associates, Houston, Texas. “It's produced a fundamental shift in all service delivery, streamlining things, and getting rid of the inefficiencies we dealt with everyday in the traditional model.”
Adds Ron Meyer, vice-president/BIM director at HKS, Dallas, Texas, “It's led to a whole new level of coordination of MEP systems. We're seeing more contractors participating and requiring their subs to participate too. Having more people involved in the design from the start makes it more efficient.”
Jonas McBride, PE, vice-president of the MEP engineering consulting firm Smith Seckman Reid (SSR), says, “BIM has been architecturally driven, but we're catching up. We've seen tremendous value to us and our clients in terms of coordination. General contractors and sub-contractors are looking at our models in 3-D, seeing how everything works and fits together, and they've had very few questions.”
McBride was alluding specifically to an expansion his firm is working on of the Brooke Army Medical Center in San Antonio, Texas, called the San Antonio Military Medical Center (SAMMC; figures 1 and 2). Wayne Barger, AIA, senior vice-president of RTKL, principal-in-charge of the project, says, “RTKL has been doing all our healthcare work in BIM, but this 780,000-square-foot addition is our largest project yet in BIM. BIM has enabled us to integrate architectural, structural, and MEP design from the start. No doubt we've pushed the software and file sizes, but it has yielded tremendous benefits. We've seen very quickly where something won't fit or conflicts will occur. In the 2-D world we'd turn over our drawings to contractors and subs, and they'd come up with long lists of things that had to be redesigned. That isn't happening now.”
The connector bridges from the existing Brooke Army Medical Center (left) to the 780,000-square-foot expansion do not slope, as the new structure was designed to match the existing one. The interstitial building space (IBS) floor is structurally suspended from the floor above, and some of the mechanical systems routed in the IBS to supply the floor below are visible
The design of the SAMMC dictated a mechanical, electrical, and telecommunications room per smoke compartment. In these stacked mechanical rooms, all the units are accessible from the floor level, while distribution occurs above the interstitial building space deck
The broadening capabilities of designers under BIM have branched off into new developments in MEP design. SSR's McBride notes, “We've gone into modeling for lighting/daylighting and for HVAC requirements, and have even produced a virtual test and balance report for HVAC contractors. They're not only seeing a 3-D model, but they're understanding how we got there.”
Walter P. Moore's Young says BIM is evolving into a basic facility management tool for MEP. “We can create a 3-D representation of the entire building, showing all the chillers, electrical switch gears, valves, etc., and tagging them in the model with hyperlinks to pdfs of model numbers, maintenance history, current job orders and the like, and operate the building in the digital world. This is coming on line pretty quickly.”
His colleague Ryan Seckinger, PE, says the design team is now able to proceed with a greater degree of precision in laying out such key MEP spaces as plenums and interstitial areas. “A high-performing team leveraging the new technology can take out some plenum space-for example, with 15 feet rather than 16 feet floor-to-floor, which reduces the façade and saves on that cost.”
HKS's Ron Meyer notes designers' new capabilities of energy analysis for MEP. “We're no longer compensating for lack of information. Before MEP designers used to react to architectural drawings pretty far into completion, but with today's BIM and energy analysis tools, we're better able to communicate.”
Brock Graham, senior project manager, Gilbane Building Company, Providence, Rhode Island, elaborates by describing “a project in Bridgeport, Connecticut, for which modern energy analysis allowed use of a heat recovery system-basically a 30,000-cubic-foot dessicant wheel-that permitted construction of a 100,000-square-foot addition without adding a chiller to the plant. The money saved on that enabled the architect to add an atrium to the building. Heat recovery technology also allows for smaller HVAC equipment, giving the architect more space for other things. It also helps with code authorities and LEED wanting to bring in more outside air for better indoor air quality because the precision of the analysis shrinks the amount of air you have to process. You can do all this now without adding equipment or costs.”
Energy analysis helped an architectural/MEP team understand the air handling and smoke evacuation requirements of a large atrium in a recent project, says HKS's Ron Meyer. “It's easier for architects to experiment with new spaces and façades, including the impact of the newer glass façades being designed now.”
It would be reasonable to assume that increased use of glass and daylighting in healthcare facilities these days would have a major impact on MEP calculations and design. However, SSR's Jonas McBride notes that “today's high-tech, high-efficiency glass usually exceeds the energy code and has virtually no impact on MEP.” McBride's architectural teammate on the SAMMC project, RTKL's Barger, agrees, noting that the U.S. Army clients preferred a glass façade for the new expansion rather than replicating the brick structure, with deeply inset windows of the 1992 parent structure. RTKL Lead Designer Eurico Francisco explains, “The use of glass allowed for a lighter, more welcoming expression of the architecture. In addition, our clients were aware that the more glass and natural light you have in a facility, the faster the healing process. Although you still have to be cognizant of building orientation and the need to minimize heat gain, modern glass technology has addressed issues that concern MEP design.”
One feature of the new Army medical center has pushed MEP design in an unconventional direction, notes Barger: “a continual interstitial level throughout each floor (figure 3). This is something virtually unheard of in private construction because of initial costs.” Explains RTKL Project Manager Alan Sneed, “The MEP interstitial space has approximately six to seven feet of clear space and typically allows for nine-foot ceilings in the occupied spaces below. Sandwiched in between the two is a separate zone for lighting fixtures, air diffusers and cabling. The building is 19.5 feet floor to floor altogether.” The great advantage of this? “It adds a great deal to the long-term flexibility and adaptability of the structure,” says Barger. “It allows for ready adaptation of new technologies and for important upgrades over time without ever disrupting patient care.”
The floor-to-floor height of SAMMC is 19.5 feet, with a nine-foot lay-in ceiling below the seven-foot interstitial building space. Without this space, future MEP maintenance or renovation projects would require disruptions to patient care as workers would have to access the plenum through the ceilings of clinical areas
Addressing private clients' cost reservations, SSR's McBride says “our government client had a certain design philosophy and wanted interstitial space that would be clean and flexible without intruding in the sterile environment below”-especially important as the medical center is heavily involved in burn care. Though it indeed added costs-the designers' current estimate is at about $50/sq. ft.-Barger notes that “we had the building structure to support this, and it resulted in approximately three to four feet of additional skin per floor.”
One feature of the new Army medical center has pushed MEP design in an unconventional direction…
In whichever direction future MEP design proceeds-more flexible interstitial areas, more tightly designed plenums or right-sized mechanicals-everyone agrees that the overall design process will never be the same. “Folks running hospitals these days are being required more and more to deliver value for the dollar, and they're expecting the same discipline from their project delivery teams,” says Walter P. Moore's Seckinger. Colleague Kurtis Young adds, “Healthcare providers are generally serial builders. They're always starting up new projects while, at the same time, hearkening back to previous projects and looking for ways to improve.
“This is why integrated project delivery (IPD) has found a natural home and momentum in the healthcare field,” Young continues. “We have a ‘perfect storm’ today of LEAN methodology, IPD and BIM all impacting project delivery strategy. We're still in early days, and there are wide disparities in levels of sophistication among clients and lots of education is needed. But we're all being asked to do more with less, and IPD-while no panacea-can be a great tool to help us achieve this. The upside potential has never been greater.” HBI
Healthcare Building Ideas 2010 Winter;7(1):18-21
