Plumbing: it may not be the most stirring topic in design and construction, but fail to get it right and nothing else much matters. Probably no other built facility places more demands and complex requirements on plumbing designers and installers than the hospital. Operating around the clock in an environment requiring complete safety, sanitation, and reliability, in a variety of settings, the plumbing system is fundamental to healthcare project success. Fortunately the “wonderful world of acronyms” has come to the rescue of hard-pressed planners of late, i.e., BIM (building information modeling), with its roots in MEP planning, and the “P” in mechanical/electrical/plumbing, which has solidly benefitted from BIM. Addressing this and other current issues in healthcare facility plumbing design is the usual Build It Right cross-section of experienced project participants, responding to questions from Healthcare Building Ideas Contributing Editors Richard L. Peck and Shannon Powers-Jones.

What are the major challenges in healthcare facility plumbing design, from an engineering standpoint?

It is obviously a more complicated challenge than it is for most commercial or office building construction. Plumbing systems are almost as expensive in healthcare facilities as mechanical systems. One recent cost-saving measure I'm seeing more of is the use plastic pipes, not just for sanitary purposes but for domestic water as well. It's about 30% less expensive to connect from hard pipes in the ceiling to various fixtures in the space using plastic pipes, and it also allows for a lot more flexibility in room layout.

Another plumbing challenge in the healthcare facility is Legionella prevention. One way to accomplish this is to run hot water tanks at 180 degrees Fahrenheit, which will eliminate Legionella. The problem with this is the mixing valves you need to deliver water at safe temperatures don't work very well-they have difficulty accommodating the temperature differences and what you often have as a result is “creep”: water temperature steadily rises during the night to the point that people taking showers first thing in the morning can have serious problems with temperatures being too hot. Our fix for this has been to install multiple hot water tanks all running at normal temperature and then each month take one offline to sanitize with very hot water.

Another challenge in healthcare plumbing design is the expense involved in using multiple isolation valves so that individual patient rooms and wings can be sealed off as needed to deal with leaks without disrupting the rest of the facility. At $200 a valve, this can get to be quite costly.

How has BIM impacted your work in plumbing design?

We just started using BIM in our firm and I'd say that, for now, the main impact has been on marketing-it helps get us jobs. Its real value is in the preplanning process before drawings are made in order to help head off any problems that might arise; these problems become quite obvious in 3-D. But it takes quite a bit of time to create 3-D models so, from a budget standpoint, it is more realistic for big jobs than for small ones. There's also a steep learning curve associated with BIM, with some people quicker at it than others. Some people are jumping into it with both feet, with lots of enthusiasm. For others, it's like pushing them uphill, and most of these folks are going to be dinosaurs in three or four years, the way things are going.

From a maintenance perspective, what are the particular safety concerns specific to plumbing systems within the healthcare environment?

First and foremost, these systems run above very expensive equipment that if damaged can cause injury or worse to the very people we are entrusted help, so careful planning and construction must be mandated to reduce the risk of a failure that would cause any disruption. Disruption of the water service is another major concern for certain patient populations as in dialysis units where the water quality and consistency must be maintained or the outcomes could be very devastating. Plumbing systems must operate with very tight temperature set point regulation to avoid any type of scalding hazards, but yet still be warm enough not to add any issues to those using it.

Sewer drains have their own set of issues based on what is in them. In our environment, a lot of our folks have weakened immune systems and any leak can cause havoc. We use all kinds of chemicals in the labs to diagnose symptoms, and they must use special piping such as acid-resistant types, so anyone servicing them must know what is inside.

Repairs to these systems usually require the use of a torch or open flame and that is always a concern for healthcare. We have started to use the crimp systems that do not require the use of torches, thus removing the safety issues of the flames, plus they are a lot quicker to repair.

What are special concerns of maintenance/replacement of components-for example, how significant are the costs?

As I noted previously, service personnel must know what is inside the pipe they are looking at-if they don't, they can expose themselves to a wide range of operating temperatures and pressures. The costs for these systems are significant, as you cannot utilize standard plumbing piping that you would find in your home. All of our piping must be copper or steel; we cannot use PVC or CPVC. Faucets and fixtures are quite a bit higher in terms of cost than you would see in a normal commercial building due to all of the special applications we have in healthcare.

What are some of the biggest challenges you have experienced with these systems and how did you handle them?

Our biggest challenge is leaks. In healthcare, the buildings are designed to help keep environments separated by the use of pressurization; we have negative, positive, and neutral areas that keep airborne contaminates out of each space, so when you do have a leak, the fluids can cross over carrying with them whatever is in the way, along with possibly contaminating the space. When this occurs, quick response and movement of those patients affected causes major issues for staff and patients.

Another issue is valves: Staff must know where they are and what they shut down, as unplanned shutdowns can cause unintended consequences. Will the valve hold, is always a concern. To battle these problems we have to implement a valve program in which each valve is identified on a floor plan and also marked on the ceiling grid to indicate the shut off and the areas it serves. We also create a work order every time a leak is repaired temporarily so we can follow up with planned replacement.

Would you discuss the plumbing design controversy concerning inboard versus outboard toilet rooms?

The recent hospital projects I've seen are split pretty evenly one way or the other. The concept of the nested toilet room between rooms draws interest until the costs and additional square feet are considered. The decision on inboard versus outboard is often based on such factors as the impact on patient visibility from the corridor (favors outboard) versus availability of exterior wall space for windows and views (inboard). There is also the question of providing space in the room for moving equipment easily without blocking corridor access (outboard) versus limiting travel distance for staff to the toilet room (inboard). When you stack patient room and critical care area plumbing, critical care nurses can dispose of materials and do handwashing without having to cross the room, for instance. Another major factor is the patient's perspective. In that case, toilet room privacy and availability of exterior views favors inboard.

What about the plumbing impact of the same-handed room concept-doesn't this require a lot more installation than shared, back-to-back plumbing would?

It has generally been thought to be more expensive, but I've heard contractors say that stacking the plumbing vertically with a lot of repetition, this can offset the cost of increased plumbing for same-handed rooms. In fact, there are subcontractors who prefabricate vertical risers off-site for more efficient installation on-site. We may be getting to the point where our ability to better coordinate the systems during design can enhance construction methodology, minimizing the cost factor for same-handed design.

How do you avoid the possible monotony same-handed design can cause from having the same fixtures in the same place in every room?

Breaking the plane of the floor plate helps. For example, at the Amplatz Children's Hospital at the University of Minnesota, our firm grouped same-handed patient rooms into four nursing neighborhoods of six beds each, separated by notches housing a children's play area and a conference room on each floor. A project I worked on for my previous firm, Perkins+Will, at Rush Presbyterian in Chicago was a so-called “butterfly” layout, with groupings of eight same-handed rooms. Both arrangements gave nursing staff ample access to supplies and positioned the support spaces to animate the corridor. Of course, anything you can do from a design standpoint to de-emphasize long corridors by using color, signage, or recessed doorways can help avoid monotony as well.

What are some other design considerations pertaining particularly to plumbing areas in the hospital?

The entrance to the toilet room has become an important issue-specifically, its size. We're finding that the standard three-foot-wide entrance is not sufficient for wheelchair patients requiring assistance or bariatric patients, for example. More and more we're seeing 42 to 48 inches as the typical size. But with this shift comes the issue of positioning the toilet room door. An outward swinging bathroom door may block the room entrance on the inboard side or impinge on the family sleep sofa on the outboard side. Adequate clearance space has to be accounted for.

Another consideration is that hand sanitation is a major factor in controlling infection. As designs continue to evolve, the placement of the handwash sink or handwash gel will continue to be a major factor in both patient room and nursing unit design.

Have you seen much in terms of sustainable or green design with respect to plumbing?

Almost all healthcare projects I'm seeing these days are addressing water conservation, especially recapturing runoff from mechanical and stormwater systems for use on indigenous landscaping. Green design has gotten to the point where it is not the cost premium it used to be. Seven years ago, we had very few of the products or smart materials that we have now; choice is important in mitigating costs. Furthermore, there is emphasis on doing what is right for the long term, so I expect we'll see water conservation being a major focus of healthcare facilities for years to come. Will we get to the point where waterless urinals become the norm in hospitals? Only time will tell.

How apropos has been the use of BIM in these designs?

This new technology will have as much impact on plumbing design as CAD did 30 years ago. The ability to quickly see the results of two-dimensional designs in context of all of the other building features will bring many benefits to both building owners and contractors. Hospital ceiling spaces are crammed full of plumbing/medical gas ductwork and low voltage systems, all competing for critical pathways. These pathways are important to the construction phases of projects, and they are equally important to maintaining these systems in the future. BIM deals with recurring challenges I've had in almost every job I have been involved with, including conflicts with other systems, six-inch pipe in four-inch walls and difficult access to cleanouts and valves. Coordination drawings have been in our specifications for years, but the technology lagged until the more prevalent use of BIM. Two-dimensional overlays do not always catch problems that show up in the field, and contractors are not always aware of the total requirements of all trades needing access/space in the ceiling space. In the past, the only way to handle these issues was with costly changes. Now, better planning through the use of BIM will allow designers and subcontractors to identify problem areas and make changes prior to issuing construction documents or starting building in the field. All trades will have a clear picture of what is in the space and how they will need to install their portion of the work.

What did you consider to be an exemplary MEP project?

Our recent chiller replacement project comes to mind, as it was well designed with contractor input, making the implementation efficient in terms of cost and schedule. All three mechanical contractors we have on our preferred bidders list had an opportunity to review the plans and provide input on constructability issues. Our contractors recommended changes to the documents and pointed out areas for cost savings prior to bidding. With the resulting complete understanding of the requirements and expectations, the changes were incorporated into the documents and the scheduled days were met. The only change orders were for owner requested changes and corroded pipe uncovered during the installation. HBI