College of Engineering, Technology, and Aeronautics building, Southern New Hampshire University, in Manchester, N.H.
Anton Grassl / Anton Grassl Photography College of Engineering, Technology, and Aeronautics building, Southern New Hampshire University, in Manchester, N.H.

Gabled barns, slate roofs, and covered bridges abound in New England, but a recent project by Minneapolis-founded HGA brings them together at Southern New Hampshire University, in Manchester. Completed in January 2020, the College of Engineering, Technology, and Aeronautics building contains laboratories, classrooms, a wind tunnel, a drone arena, maker spaces, and multipurpose studios. This 21st-century program is housed in a three-story, 67,000-square-foot building defined by a pair of long, barnlike volumes linked by a timber-framed atrium that nods to the interior of a covered wooden bridge, but larger and brighter. The building’s exposed stone foundation and exterior skin of slate shingles strengthen the barn metaphor while its sleek detailing gives the education hub a high-tech character and precisely crafted envelope that must withstand Northeastern winters. Copper-clad dormers and expansive glass curtain walls shaded by aluminum fins break up the slate wrapper.

HGA, with builder Skanska and carpentry and roofing subcontractors, leaned into the project’s craftsmanship. (HGA acquired the project’s original designer, Boston-based Wilson Architects, in late 2018, near the start of construction.) Instead of the deep eaves typical of a barn, the slate roof crisply folds down to become slate walls, with just the barest of overhang. Building corners are devoid of visible exterior flashing. “Typically, to make it easy, you’d cover the corner,” says HGA principal-in-charge and science lead Chris Martin, AIA. “We wove the pieces of slate at the intersections of the roof and wall planes to keep everything sharp and clean.”

The slate shingles on the roof and wall transition nearly seamlessly.
Christian Phillips / Christian Phillips Photography The slate shingles on the roof and wall transition nearly seamlessly.
Christian Phillips / Christian Phillips Photography

According to HGA project manager Cristianne Peschard, AIA, the transitions between materials—from the slate roof to the copper flashing, slate rainscreen to glass curtain wall, and rainscreen to stone base—were crucial to the overall design’s successful execution. The building envelope, with its precise detailing and clean joints, is “like jewelry,” HGA design principal Samir Srouji, AIA, says. “The tradespeople [understood] the idea of what we were trying to do and they contributed to the details.”

Mock-up of shingle detail at corner
Cristianne Peschard / HGA Mock-up of shingle detail at corner

The first of two full-scale mock-ups allowed the team to test the design of the slate-shingle system with woven corners. A second mock-up, erected on the SNHU campus, allowed the architects and builders to perfect the connections between different materials.

A durable rainscreen system by Cupa Pizarras, in northwestern Spain, begins with slate shingles that are “minimally expressed” so they visually cohere into an overall smooth and lustrous wrapper, Srouji says. Each course of shingles, which individually measure 20 inches long and 6, 8, or 10 inches high, overlaps the course below, concealing their screws attaching them to aluminum furring. This substructure fastens into a metal stud frame wall by brackets, creating an air cavity. Behind the air cavity is a layer of 3-inch-thick mineral wool insulation, exterior gypsum sheathing, a continuous air and vapor barrier, and then R-13 batt insulation. Most interior walls are finished with painted gypsum wall board, while the glazing of the expansive curtain walls has a U-factor of 0.45.

Wall section above curtain wall
courtesy HGA Wall section above curtain wall
Cristianne Peschard / HGA
Full-scale mock-up of exterior envelope
Cristianne Peschard / HGA Full-scale mock-up of exterior envelope
Anton Grassl / Anton Grassl Photography

Inside the building, the lofty, light-filled spaces are flexible by design. Ceiling-mounted cord reels for power and an overhead distribution of plumbing services combined with rolling studio desks allow the labs to be reconfigured quickly. Some areas leave exposed the structural and mechanical systems, treated with acoustical and fireproofing coatings. As for those steep roof planes? The building had to be tall enough to accommodate bulky equipment in an enclosed mechanical penthouse. Snow guards on the roof help stabilize potential sheets of ice or snow from sliding down.

In their heyday, wooden barns and bridges embodied the spirit of engineering. By revisiting these vernacular New England forms, HGA blends the familiar with the cutting-edge.

College of Engineering, SNHU
Anton Grassl / Anton Grassl Photography College of Engineering, SNHU
Anton Grassl / Anton Grassl Photography