“The vertical and horizontal interstitial spaces in a research lab are fixed for the life of the building, yet the ability to adapt to changing equipment and research needs depends on the functional design of these spaces,” says Barbara Hopewell, principal with Zeidler Partnership Architects in Toronto, Ontario, Canada.

In addition to increased flexibility, other advantages of creating proportionally larger interstitial spaces include ease of maintenance access, efficient waste elimination, and ability to rapidly change research emphasis.

“These details really need to be worked out in the design phase because after construction begins it is nearly impossible to change interstitial spaces,” says Hopewell.

Since research type dictates support needs, the first step in the planning process is to determine a facility’s research emphasis, but often the scientific focus of a facility changes between the initial planning phase and the final build out. The ability to adapt to these changes is greatly impacted by the predetermined amount of dedicated MEP space.

The Toronto Medical Discovery Tower (TMDT)—a 15-story, 400,000-sf biotechnology center in Toronto’s MaRS Discovery District—recently faced interstitial-related limitations when the strategic research focus changed midway through construction to include medicinal chemistry.

“The tower was originally designed as a biology facility, but halfway through construction the decision was made to add a medicinal chemistry group. We were able to accommodate the required changes, but it was a considerable challenge,” says Ian McDermott, director of Research Facilities Planning for the University Health Network, which operates the TMDT.

Every floor in the TMDT has two mechanical spaces, on the north and south sides, respectively, which supply air to half the floor. The penthouse mechanical space is dedicated to exhaust systems and some centralized gas systems.

“The vertical interstitial shaft space in that facility is only two percent, which proved to be insufficient, but there is absolutely no way for us to modify it. The floor plate is fixed in the interior part of the building,” says McDermott.

Airflow Demand and Capacity

One of the first challenges planners encountered when adding a medicinal chemistry group to the TMDT was accommodating the increased amount of needed airflow.

The facility, which has a 25,000-sf floor plate, was originally slated to have between 16 and 20 4-foot standard fume hoods on each floor, but medicinal chemistry labs require an 8-foot chemical fume hood for each researcher. This issue was resolved by removing the standard fume hoods along the south wall of the fifth floor and replacing them with 14 chemical hoods. Due to the volume of chemicals involved, the fume hoods must have supporting cabinets as fire compartments, requiring a larger volume of air flow to ensure appropriate exchange. These demands taxed the facility’s air handling capacity.

“We have literally maxed out that floor. There is no way to put another medicinal chemistry hood in there with our current shaft space. By my estimates, a typical 25,000-sf medicinal chemistry floor would require four times more vertical interstitial space,” says McDermott.

Though the facility’s cabinets are exhausted back to the room, there is a strong global push to exhaust all biological safety cabinets to the exterior, which will further increase air handling needs for any BSL-rated facility.

Radioactive materials can also drastically increase air handling and support space requirements, depending on the isotope. Designers of the TMDT achieved floor space efficiency by consolidating all radioactive work to one area in the center of the building with a fume hood and a dedicated riser.

“Radioactive exhaust requires a dedicated riser because you can’t put it through a mixed exhaust system. So, we were limited in how many we could install. We really need to have two to five work areas, which, for radioactive exhaust with a dedicated riser, would require twice the amount of vertical shaft space,” says McDermott.

Specialty Lab Support Space

Specialized lab areas require greater amounts of support space than traditional labs, but these needs are often not recognized until after the base building design is complete.

NMR/MRI suites require pipe quenching capabilities and the ability to emergency exhaust vaporized cryogens, which can double a facility’s MEP space needs.

Computer server rooms also demand considerably more MEP space than typical labs because accessibility is essential for cooling and monitoring of equipment.

Ensuring there is enough space for easy access to both supply and exhaust HEPA filtration systems is another important issue that is often overlooked.

“The use of hydrogen peroxide for decontamination means technicians will need to be able to get in and monitor those spaces. In cases where the shafts are really small, it’s almost impossible to get to them,” says McDermott.

Minor Changes, Significant Results

To determine the best MEP proportions, the design team analyzed the interstitial building ratios of a range of facilities—including the Center of Marine Biotechnology in Baltimore; the new Scripps Institute in Palm Beach County, Fla.; and buildings in Toronto’s MaRS Discovery District—to determine the optimal balance.

“We analyzed typical floor net and gross ratios, floor volumes, building volumes, and the gross efficiency of the entire building,” says McDermott.

Whole building volume ratios turned out to be very similar. Mechanical interstitial space, including the mechanical penthouse area, accounted for approximately 50 percent of total building volume, with an average of two percent dedicated to vertical shaft space. To maximize flexibility and cost efficiency, Hopewell recommends that labs dedicate approximately five percent of floor plate to interstitial shaft space.

“Four out of five projects that we analyzed contained approximately two percent shaft space relative to the floor plate, which was insufficient. Our current recommendation is to strive for at least five percent,” says Hopewell.

“Increasing interstitial space by even two percent makes a big difference in terms of flexibility and doesn’t significantly increase building envelope or project costs,” says McDermott.

Outside is the New Inside

Another approach to improving service flexibility is to use epistitial space by placing vertical shafts on a building’s exterior as part of the architectural design. This approach may be limited by the need to keep services centralized, or, as in the case of the TMDT, because the building is surrounded on all sides.

“Using epistitial space provides flexibility to increase shaft size as demand grows because the spaces are not restricted by the confines of the building,” says McDermott.

Animals Need Air Too

Almost all medical research buildings have animal spaces which require increased airflow and strategic plumbing-related interstitial planning.

“Drainage for large animal waste is an issue that is often overlooked. It’s important to think about where those drains are going. They can’t just mix with anything and they can’t have 90 degree angles because they get clogged,” says McDermott.

Small animal holding facilities traditionally utilize a waste evacuation system that cleans out cages and transfers waste to a holding area on the ground floor to be trucked away. This system requires direct vertical shafts with no 90 degree turns. Because of pre-established design parameters, there was no place to run a vertical shaft for waste transfer in the TMDT, which means small animal waste must be bagged manually.

“We had to incorporate a lot of fairly costly, complex systems to accommodate programmatic changes in the final development. It’s not the ideal way to do things. Having less complex systems means making fewer modifications later on, and that starts with proper planning,” says McDermott.

By Johnathon Allen