In 2015, we designed renovations for the Longfellow School on Great Cranberry Island. The school building is over 100 years old, and serves the community as an assembly space and public library.


The main objectives for this school renovation were to bring the building up to current fire and life safety codes, energy efficiency, and compliance with the 2010 Americans with Disabilities Act. We designed a commercial public lift (Limited Use Limited Accessibility) placed inside the existing building. We replaced the aging fuel oil boiler, provided ventilation with a new mechanical system, and designed energy improvements to the building exterior. We also investigated the structural system. We discovered the building structure inadequate. Neither the first nor second floors were built to support the structural loads required for assembly spaces. Structural deficiency, or an inability of a building to meet current structural design criteria, is not a reason to abandon a building. Rather, owners might choose to limit the number of people who are allowed on the floor at one time. In this case, the owner chose to strengthen the building floor structures to meet today’s code requirements. Residents who have visited the school recount stories about the second floor bouncing, with a visible sag, during meetings or dances.

Snow Loads

Snow load is another structural issue that comes up with in a school renovation, especially when energy efficiency measures are taken. Older buildings often lacked roof insulation, so snow melted from heat within the building that propagated to the roof surface. By adding energy-saving insulation to a roof or ceiling, that heat transfer stops. Snow takes longer to melt, and the building risks increased snow weight stressing the roof structure. Thus, structural reinforcing is often part of the project when we add insulation to older buildings.

  • Name Longfellow School
  • Type Education
  • Location Cranberry Isles, Maine
  • Year 2016