Inside Cover D — September 2023 — M id A tlantic Real Estate Journal
www.marej.com
E ngineering
he COVID-19 national emergency unques- tionably left us with By Rory Creegan, PE, AKF Group Good Bones: Analyzing existing commercial structures for healthcare repositioning T
for creativity” as the size and shape of an existing build- ing will rarely be an ideal playing field for the modern medical program layouts to which our designers, patients, and staff have become accus- tomed. Beyond that, there are many infrastructure considerations that should be discussed between the owner and design team in the early stages of considering a building for repositioning. The following topics are “food for thought” for a prospective tenant or owner looking to occu- py an existing structure. Chal- lenges outlined in this article are not meant to be deterrents, as each of these scenarios can be overcome with proper fore- sight and creative coordination. As always, requirements of a program should be specialized to meet the needs of the owner, staff, and clientele. To that end, this article may be a good start- ing point, but certainly not a comprehensive list. STRUCTURE: First, analyze the “bones” of the building itself. Many va- cant structures were built as office buildings decades ago. The International Building Code requires the structure of an office building to support 50 pounds per square foot for new office program area, while hospitals require live load support between 40 and 80 pounds per square foot, with 60 pounds per square foot for surgical program. Much can be done to strengthen a struc- ture to support an ambulatory surgery program, but it must be considered that most struc- tural improvements will have severe impacts on the ceiling heights of the floor below. Many modern outpatient programs attract clientele by providing local access to medi- cal imaging. These programs certainly increase patient traf- fic but can also have serious structural impacts. A 3T MRI machine could weigh 100-150 pounds per square foot and often requires supplemental steel to support not only the equipment location, but the delivery path as well. For that reason, it is often recom- mended to keep the imaging program on the lowest floor of an adaptive re-use program. The roof structure is an- other area worth exploring. As we will discuss below, the mechanical systems of an older office building may
need to be replaced (or heav- ily supplemented) to meet increased loads and ventila- tion requirements of most healthcare programs. Most spec office buildings were not constructed with the intention of large equipment on the roof but will soon have to bear the weights of air handlers, chill- ers, and exhaust fans. For the most part, the quickest and most cost-effective solution may be to install a framework of new dunnage under the pro- posed equipment, supported by existing column caps. IMAGING: In addition to the struc- tural implications mentioned above, adding medical imag- ing to a commercial building requires a closer look at both the room location and equip- ment requirements. The large machines need dedicated de- livery and replacement paths, and the critical nature of the equipment can require supplemental cooling, vibra- tion isolation, uninterrupted power sources, and dedicated exhaust and vent routing. It should be expected that existing office buildings of a substantial size would be provided with a central me- chanical air handling system, perhaps even one that has been properly updated and maintained. Most of these systems will likely be sized between 0.75-1.25 CFM/SF, and most modern healthcare programs require a larger capacity system due to an increased cooling load and an increase in code-required air changes. The upsized air sup- ply system will also require an addition to the cooling and heating infrastructure (chill- ers and boilers), the size of which heavily depend on the local weather design criteria. Larger air supply systems also mean larger shaft areas and lower ceilings due to upsized infrastructure path- ways. (Sorry, space program- mers!) However, there are tips and tricks to minimize this interruption. One item to advocate for is, as strange as it sounds, more shafts! As the infrastructure across a floor is split between additional shafts, ducts and pipes leaving each individual shaft can be reduced in height, allowing for more flexible ceiling features. Many outpatient services MECHANICAL AIR SYSTEMS:
like exam rooms, infusion programs, and offices can be served by a chilled beam system. Chilled beams are ceiling-mounted units that recirculate air in a room over a hydronic tempering coil (both heating and cooling) to maintain the temperature in a space. Since the space is mainly tempered by this recir- culated air, the ductwork from the roof or mechanical room can be reduced to only carry ventilation air, reducing the duct size by 60-70% and offer- ing more favorable shaft sizes and ceiling height flexibility. To offer a deceivingly simple tip – use what’s there! Many older buildings were devel- oped with beam or joist pen- etrations to weave the original infrastructure through to ar- eas of service. If a new design can re-use even a portion of these pathways, it could mean a significant increase in pro - posed ceiling height. PERIMETER HEATING SYSTEMS: While the cooling load in a repositioned healthcare building will likely increase, the heating load may remain within a similar range. There are many potential space pro- grams that do not require up- grades to perimeter heating, such as office and research areas. However, the fin tube radiators of a commercial space may be infection con- trol nightmares for modern surgical suites and patient recovery areas. The cleanest solution may be heating by air alone, as- suming the façade can be mod- ernized and insulated to sup- port a window facing linear diffuser. In scenarios where this approach is not enough to combat the infiltration or peak of winter conditions, a radi- ant panel may offer desired occupant comfort without the worry of collecting debris or infectious particles. POWER DENSITY: Unless the new program consists of only exam rooms and offices, the power den- sity in a repositioned building should expect an increase. An office floor plate is typi - cally provided with approxi- mately 6 watts per square foot for lighting and receptacles, while a healthcare occupancy could require 10-20 watts per square foot for the same area. The increased capacity of electrical infrastructure re-
quires more physical space, including incoming service rooms (typically on the lowest level), and distribution rooms. One way to curb a potential increase in vertical pathways, and therefore decrease shaft space and conduit, is to sepa- rate the building into upper and lower house distribution. While separating into two distribution centers may in- crease the quantity of some equipment (transformers, etc.) the total quantity of panels will remain approximately the same. This approach can save on long lengths of distribution wiring, whose fluctuating price has been a burden to many projects in recent years. Emergency power density is another item that begs further consideration. An office space might only require emergency power for fire services and egress lighting. Depending on the program, there is a huge variation in healthcare pro- gram requirements – but the load will almost certainly in- crease. Surgical and recovery units will likely require three branches of power per NEC (NFPA 70), and many patient safety loads to be added to an emergency power source. Cooling and heating systems serving critical areas should also be considered additions to the building emergency load. Typically, a new generator is required to serve these needs. In an urban setting, this generator may need to sit on the roof and require ad- ditional dunnage (see Struc- ture section above). In a more suburban or rural setting, a generator may be mounted on grade adjacent to the building structure. A note regarding electrifica - tion: as many design teams and project goals move away from fossil fuels, there is a tendency to think of air-cooled systems (chillers and heat pumps) as a cure-all solution. These systems should be celebrated for the way they provide comfortable space conditions without burn- ing fuel, as well as their user- friendly layouts, redundancy, and simple maintenance. How- ever, a designer or owner needs to make the upgrading of the electrical system a priority to support such a change in infrastructure (in both owner and tenant scenarios). A change to air source heating and cool- ing could increase mechanical continued on page 10D
an altered landscape. While life has returned to normal (or a version of it) for most, there are many as- pects of our
Rory Creegan
daily lives and industry that will never be the same. Among these changes is the ongoing ability to work from home. In January 2023, nearly 30 percent of all work was performed from home (accord- ing to data-collection project WFH Research 1 ). While this brings to mind a montage of employees in comfortable sweatpants, parents spend- ing more time with children, and healthier lifestyles, it can also conjure a more conflicted image in the real estate world – empty office chairs. NBC News recently report- ed that 12.8% of office real estate remains vacant 2 , call- ing it the highest percentage since the great recession. So, what is a community to do with all of these empty build- ings? Healthcare providers have an idea. As more Americans move their lives closer to home, there is a strong argument to bring their healthcare with them. Outpatient care is ex- pected to grow 16% over the next decade, and established healthcare systems have be- gun to compete in this “race to convenience” building am- bulatory surgery, cancer care, low acuity imaging, and exam centers in the furthest reaches of their geography. With a quick construction schedule in mind, recently vacated office buildings offer a unique opportunity for a healthcare service to occupy a central location in any com- munity. While the location and size of these buildings may be attractive qualities, a prospective tenant or owner should be forewarned that not every building is perfectly suited to house a healthcare occupancy. In fact, even the most well-appointed build- ings will need a fair amount of renovation work to serve a new healthcare program. The usable floor area and options for new program lay- out are the first “opportunity
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