The Challenge

Structural Coordination

We were asked to build a new retreat center in Kensington NH using the Passive House approach, which is characterized by quality design and craftsmanship, energy saving features, and a unique blend of construction types. The building structure was to be a hybrid of four interconnected timber frames — one reclaimed from a 200 year-old barn in Maine — atop a concrete and steel lower level. A structural steel system was to give the timbers lateral support, while a stick-framed “overbuild” would level the roof lines and exterior walls, and hold structural insulated panels (SIPS). Connecting the structural steel and overbuild to the timber frames — which were not level, square, or plumb — presented a unique set of challenges.

The Callahan solution

Through careful coordination between our timber-framer, steel subcontractor, and structural engineer, we developed alternate connection details that allowed for the inconsistencies in the timbers. After determining that certain steel members could not be fully fabricated in the shop, we also coordinated timber framing and steel work so that steel members could be shipped to the site long, field measured, and fabricated on-site for a custom fit, all while maintaining the Passive House Standard.

  • First building in New England to meet the Passive House Standard
  • Concrete and steel foundation
  • Reclaimed timbers from 3 barns
  • Low energy consumption
  • Triple-pane windows
  • High levels of insulation
  • High end exterior finishes
  • 12,703 square feet
  • Completion time: 14 months
  • Contract value: $10,000,000
“Throughout the initial negotiations and continuing to the current phase of construction, Callahan has demonstrated the highest level of professionalism. Construction has gone smoothly due to Callahan’s consistent and reliable communication methods and their due diligence process has helped to mitigate any potential issues.”

More Solutions