Such Great Heights – Meet the New Crop of Rooftop Playfields

The tighter the site, the more creative the solutions. The rooftop playfields at St. Thomas School and the Seattle Academy deliver a unique student experience and are excellent examples of resourceful, urban design.

Seattle Academy of Arts and Sciences Middle School

The Seattle Academy of Arts and Sciences Middle School is one of the few vertically-oriented middle schools in Seattle. Situated at the intersection of Union Street and 13th Avenue in Seattle’s busy Capitol Hill neighborhood, the middle school adapted to its urban setting as well as its commercial and mixed-use neighbors.


  • Elevating the playfield to the roof provides valuable outdoor space for physical activity.
  • Planning for vibrational performance was essential. To minimize the vibrational effect of active participants and additional loads, the team carefully sized of each of the long-span steel trusses that support the gymnasium roof.
  • The structure is post-tensioned concrete, with the double-height gymnasium’s roof utilizing long-span steel trusses to support the project’s signature rooftop playfield. And of course, a free-standing net enclosure was also designed to protect wayward sports equipment from dropping to the bustling street below.
  • To remain under the building’s height limit, the team fine-tuned the loading on the net, accounting for any ice and snow accumulation, to keep the net structure as shallow as possible.


  • The school’s densely populated location was also a significant design consideration. Our civil team designed around SDOT’s Madison BRT project, which influenced the project’s frontage improvement design.
  • We coordinated heavily with the city throughout construction to relocate overhead power lines across the street to create a non-standard, permanent location in the Madison BRT Transit Island. The project avoided substantial setbacks, maximizing the buildable site area and project programming.
  • Phased construction was vital for students’ safety, to protect adjacent sites, and to keep traffic flowing smoothly.


  • Inside, community learning spaces are prioritized. Multi-height, stepped interior features provide both physical and visual connectivity between grades.
  • A double-height atrium is central to the building. Each floor of the six-story structure represents a different student grade level. Due to the tight site and unique floor plates, significant coordination was required for the different building levels.
  • Bold graphic elements are prominent throughout the building, from the specially designed carpet and ceiling plates to the exterior’s faded brick pattern. Our team detailed the complicated exterior brick cladding that accommodates curtainwalls and an atypical window pattern, minimizing in-field corrections.

Project Team: Owner: Seattle Academy / Architect: LMN Architects / Civil & Structural Engineer: Coughlin Porter Lundeen / General Contractor: GLY Construction / Mechanical & Electrical Engineer: PAE Consulting Engineers / Athletic Field Consultant: D.A. Hogan & Associates / Kitchen & Food Services: JLR Design Group / Lighting Design: Dark Light Design / Acoustic Consultant: Stantec / Landscape Designer: Swift Company

Images © Lara Swimmer

St. Thomas School Performing Arts and Gymnasium Building

Located in the Medina suburbs, St. Thomas School underwent a major three-phase renovation and expansion intended to provide much needed athletic and performing arts space for the growing student body. As highly regarded parts of their core curricula, the development of these facilities was approached with extreme care.


  • Thomas School’s rooftop playfield is an excellent example of the school’s desire to make the most of their tight site.
  • Designing the playfield required significant coordination with the joist manufacturer to size cambered joists and provide mechanical connections to the concrete slab of the playfield.
  • To create a great play experience, our structure needed to be rigid enough to minimize vibrations on the artificial turf. The braced frames of the gym are 25-50 percent bigger than normal to account for the larger roof loads.
  • In addition to standard play sports equipment, the playfield is surrounded by 20-foot-tall fencing. But that’s not all, planter beds incorporated into the parapets make up three-fourths of the playfield’s perimeter. Trees are expected to sprout from these parapets in the coming years!


  • The project’s first phase consisted of site development for acquired land from the adjacent golf course. This involved transitioning the space from golf storage facilities into one that was campus-ready. As part of this phase, our team designed foundations for two new steel prefabricated buildings that now house golf equipment and a wash facility for the golf course.
  • The final phase included an interior remodel of the existing gymnasium with a self-supporting, 7,200 SF second floor addition inside the two-story space. The remodeled area now houses classrooms and a Center for Learning Innovation.


  • Phase two saw the construction of the new two-story performing arts and gymnasium building. The new building includes a gymnasium with a regulation-size basketball court, theater space, dance studio, and rooftop playfield.
  • Transforming spaces easily was essential to the program, so a vertically folding partition in the gymnasium, supported by two deep beams, allows the door of the theater to rise for additional performance area and flexible seating.
  • Insulated metal cladding panels were used for their high energy efficiency and to reduce the construction schedule. Special detailing was required to incorporate these innovative panels.

Project Team: Owner: St. Thomas School / Architect: Bassetti Architects / Structural Engineer: Coughlin Porter Lundeen / General Contractor: Sellen Construction Company / Mechanical & Electrical Engineer: PAE Consulting Engineers / Theater Consultant: PLA Designs / Industrial Engineer: Pinnacle Consulting Group / Acoustic Consultant: Stantec / Landscape Designer: Site Workshop

Images © Moris Moreno