WARP 10 Structural Design of a cGMP Manufacturing Facility Using Mass Timber

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In Star Trek, Warp 10 represents the theoretical speed limit of the universe. United Therapeutics (UT) adopted the name for its newest North Carolina project, WARP10, signaling an ambition to push the boundaries of sustainable design and construction. While the facility does not bend space and time, it aims to achieve something unprecedented in the life sciences sector: to realize a Current Good Manufacturing Practices (cGMP) pharmaceutical manufacturing plant built largely from mass timber and designed to approach zero carbon.

The project is defined by four primary objectives: maximize manufacturing throughput, meet cost targets, deliver an operational facility by 2027, and achieve both net zero operational carbon and net zero embodied carbon. The 196,000-square-foot facility includes manufacturing, warehousing, laboratory, office, and central utility plant.

From the outset, UT prioritized sustainable material selection. The resulting hybrid structure combines mass timber with steel framing, incorporating green steel, low-carbon concrete, organic cladding materials, and rooftop photovoltaic systems. Traditional cleanroom systems and finishes are used within the manufacturing environments to meet stringent operational requirements.

The 12-acre site within Research Triangle Park is surrounded by mature trees and pedestrian walkways. The building responds directly to this setting, expressing UT’s sustainability ethos through the use of mass timber framing, timber curtain walls, and Shou Sugi Ban charred Accoya wood siding.

The project was designed under the 2018 North Carolina Building Code which references ASCE 7-10 Minimum Design Loads for Buildings and Other Structures. This version of the International Building Code (IBC) provides very limited guidance for mass timber. Although wind controls the building’s lateral design, seismic requirements required special attention because ASCE 7-10 does not list mass timber frames as recognized seismic force resisting systems. Selecting an appropriate R (response modification) value therefore required careful evaluation. The 2018 North Carolina code also references the 2015 National Design Specification (NDS). However, the 2018 NDS, which was the latest code available at the time of design, was used to take advantage of its more current and comprehensive provisions for mass timber. The provisions from the 2021 IBC for special inspections were utilized for the mass timber construction.

Site preparation required demolition of an existing building and parking lot. Subsurface conditions included residual soils and shallow weathered rock, with approximately 50 feet of slope across the site. Blasting was required on the eastern edge, with fill placed on the western portion (Fig. 1).

A ground improvement system using rammed aggregate piers increased allowable soil bearing pressure to 6,000 psf, reducing the volume of concrete required and supporting the project’s carbon reduction goals. Rock anchors were introduced to provide uplift resistance at steel-braced frame locations.

Concrete mix designs were optimized to minimize embodied carbon, incorporating Type 1L cement, fly ash, slag, and CarbonCure technology, which injects CO2 during production to reduce overall carbon footprint.

The building is organized into four primary components: the central utility plant, manufacturing area, office space, and warehouse/lab areas (Fig. 2).

The two-story CUP anchors the western side of the facility and supports all manufacturing utilities. Due to operational demands, it is primarily steel-framed. The second floor consists of steel wide-flange beams supporting a composite concrete slab on a metal deck. The low roof of the CUP contains a very large cooling tower and screen wall supported on a steel-framed platform with posts to the low roof steel. The roof framing consists of steel beams supporting an untopped metal roof deck. Horizontal steel angle diaphragm bracing is provided in the roof’s plane to enhance the diaphragm capacity due to the heavy mass of the cooling tower. The high roof over the CUP consists of wide-flange steel beams supporting 3-ply, 4-1/8 inch thick CLT roof panels (Fig. 3).

Lateral wind and seismic forces are resisted by conventional concentric steel braced frames. In order to meet the carbon goals of the project, steel was carefully sourced from mills with the capacity to meet the EPD performance criteria required for the project. The majority of wide-flange steel sections sourced for the project were produced by Gerdau Long Steel North America at their Petersburg, Virginia, steel mill.

The manufacturing zone is a two-story, high-volume space containing cleanrooms, clean utilities, and extensive MEP infrastructure. The volume of the space was primarily driven by the height of the cleanroom ceilings, which ranged from 8 to 16 feet in height.

A 23,800 square foot mechanical equipment platform spans the 315-foot length of the manufacturing space. The structure for the manufacturing area is a mixture of conventional steel framing and mass timber framing. The mechanical platform consists of wide flange steel columns supporting conventional composite steel framing topped with a concrete slab-on-metal-deck. Conventional composite steel framing was chosen for the platform due to the large number of utilities and large clear spans below to service the manufacturing space. The remaining framing for the manufacturing space consists of glulam columns and beams, and a 3-ply CLT roof deck, to minimize the project's embodied carbon.

The column grid spacing approaches 54 feet, and clear heights of 35 feet were required in the manufacturing space to achieve the manufacturing program, which led to glulam column sizes approaching 20-inches square with glulam roof beams as large as 11½ inches wide by 435/8 inches deep. The exterior wall along the northern side of the manufacturing area is 35 feet tall and is comprised of 7-ply, 95/8-inch thick CLT panels. Lateral forces in this area are resisted by a combination of conventional steel-braced and moment resisting frames (Fig. 4).

Due to the project's warp speed, trade partners were brought in early to assist the design team. Nordic Structures was selected by the construction manager DPR to provide the mass timber framing. Nordic was able to use drawings from the schematic and design development phases to estimate and reserve the wood fiber volume early, allowing the maintenance of the fast-paced construction. Approximately 150,800 cubic feet of wood fiber was required for this project and was sourced from Nordic’s FSC-certified sustainable forest located in northern Canada. The team used glue-laminated timber for the beams and columns with cross-laminated timber for the walls, floor, and roof decks. The wood species for all timber framing is spruce-pine-fir. Most of the glulam columns and beams exposed to exterior conditions are Alaskan yellow cedar (Fig. 5).

The office area is a 31,000-square-foot, two-story space and provides office, collaboration, conferencing, and amenity spaces. The structure in this area highlights UT’s sustainability philosophy, as it is entirely framed in mass timber. To create large open spaces, the clear spans of floor beam framing range from 38 to almost 44 feet, with girders spanning 33 feet. Glulam floor beams range in width from 9½ to 11½ inches and are 35 inches deep (Fig. 6).

The 41-inch-deep girders supporting the floor framing are dropped in the center bay of the building to facilitate space for utilities. The second floor was established at 16 feet to meet the elevation of the adjacent mechanical platform in the manufacturing bay for convenient access. Glulam columns for the office area are 11½ inches square. The second-floor framing is topped with a 5-ply, 55/8 inch-thick cross laminated timber deck. The CLT decking is topped with a 1½-inch thick gypcrete layer to provide the required STC rating for the floor. The roof is at an elevation of 16 feet above the second floor and is comprised of glulam columns and beams, and 3-ply, 41/8-inch thick CLT roof panels.

Lateral loads in this space are resisted by steel rod x-bracing between the timber framing (Fig. 7).

The warehouse area is a two-story, high-volume facility with ambient temperature and refrigerated storage. The storage warehouse has over 1,400 pallet positions, reaching a height of 26 feet. The racking is accessed by guided turret fork trucks, which necessitated flat concrete floors with an Fmin rating of 75. The roof over the warehouse and laboratory areas provides a clear height of 38 feet. The warehouse and lab areas were another location where UT’s sustainability philosophy is highlighted. Roof framing consists of glulam beams and girders supporting a 3-ply CLT roof deck. The volume of the space was primarily driven by the required number of pallet positions.

Clear spans of the roof framing vary from 31-feet to almost 44-feet with 15½ inch square columns supporting the roof. A 5-ply CLT wall separates the warehouse from the manufacturing to the north, and a 3-ply CLT wall separates the laboratory space to the east. A mechanical platform comprised of glulam beams and a 5-ply CLT floor deck is provided over a portion of the lab area to provide space for mechanical and process equipment serving both the lab and warehouse. The column grid spacing over the lab contains spans approaching 44 feet. Glulam roof beams were as large as 9½ inches wide by 355/8 inches deep. Lateral forces in this area are resisted by conventional steel chevron-braced frames and steel rod x-bracing between the timber framing (Fig. 8).

The project presented several technical and logistical challenges, including column bay spacing with spans approaching 50 feet and achieving carbon neutrality goals. Compounding these was the need to design a structurally efficient building without over-designing due to carbon concerns, all while issuing structural drawings and starting construction before the internal process systems were fully designed (Fig. 9).

Concrete slab on metal deck thickness was minimized to 2½ inches concrete over 2-inch metal deck (4½ inch total thickness). This created challenges with anchorage to the concrete due to the slab’s thinness. Drilled mechanical anchors had reduced capacities. In addition, the use of the building as an intensive manufacturing facility with numerous utilities and a central utility plant led to challenges of supporting heavy loads on a very thin slab and providing anchorage for numerous utilities. Heavy utilities, including 12-inch diameter chilled water piping and heavy mechanical equipment, had to be supported with supplemental steel framing. More than 19,000 hangers are in the manufacturing area alone for the various piping, ductwork, and electrical systems. The team created an intensive 3D BIM coordination model to layout all systems and support points prior to construction, aiding coordination among various disciplines (Figs. 10-11).

The wood’s potential to shrink prompted another major consideration in the design. The phenomenon of wood shrinkage is well understood with the biggest variable starting and final moisture content. Every connection and interface between the wood framing and the steel framing, as well as with the CLT walls, needed to be closely evaluated. Provisions were made by leaving gaps for timber shrinkage throughout the building, where beams passed through the CLT walls, and by lowering steel beams.

Water management strategies to protect the exposed timber framing were critical during construction since the timber framing is to be left exposed in many areas of the finished building. Moisture affects the wood members themselves and can impact the steel in the connections if not managed properly.

Photovoltaic (PV) arrays are located on almost every available square foot of roof space. When completed, the PV system is expected to supply more than 6 million kBtu, approximately equivalent to the capacity needed to power almost 167 average American homes over the course of a year.

This output is anticipated to provide the facility with almost 40 percent of the energy it will need over the course of a year. Meanwhile, the building design, which incorporates mass timber, low-carbon concrete, green steel, optimized insulation, and organic exterior finish materials, is expected to achieve the goal of net-zero embodied carbon for the building.

One of the larger challenges and takeaways from the project is the trade-off between cost and construction time, as well as the project's scale for adaptability.

While mass timber has a higher upfront material cost than steel, the use of timber greatly accelerated the construction timeline. The schedule gains offset some of the cost premiums, which led to a reduction in carrying costs and labor duration. The building’s large structural spans supported the accelerated construction schedule while enabling flexible, adaptable manufacturing spaces. Typical lab buildings utilize a 22-foot bay span for mass timber. However, due to the structure needing to be finished before the design of the process equipment, the larger spans were paramount in aiding for future adjustability and maintaining an accelerated schedule.

WARP10 demonstrates how a quick schedule, advanced structural engineering, and a commitment to carbon reduction can successfully align. Early trade partner involvement, careful material selection, and detailed coordination were essential to meeting both an aggressive schedule and the project’s net zero objectives. By integrating mass timber, low-carbon concrete, green steel, and PV systems, the design team created a manufacturing environment optimized for throughput while minimizing the environmental impact. When complete, WARP10 will set a new standard for sustainable cGMP manufacturing facilities and support UT’s mission to deliver critical therapies with speed and responsibility. ■

About the Authors

Paul Constantini (pconstantini@ewingcole.com) is a principal and the director of structural engineering with EwingCole.

Taryn Napolitano (tnapolitano@ewingcole.com) is a structural engineer, also with EwingCole.