Gemma Observatory

This private astronomical observatory is located on a remote mountain summit in central New Hampshire. The site is characterized by granite outcroppings and is situated at the center of a three-mile radius “dark” landscape with very little light pollution to obstruct astronomical viewing.

Gemma’s design rejects a traditional dome in favor of a synthesized architectural form that maximizes usable space and responds to the stark geographic context. Its continuously faceted shape reflects the surrounding landform, and terraced concrete platforms transition between the summit’s bedrock and the building foundation, knitting together natural and man-made landscapes. An unconventional pattern of lock-seamed zinc cladding mediates between the irregular site topography and the building’s geometry, reflecting Gemma’s orientation to both geological and celestial landmarks. Its dimension, color, and patina evoke a material relationship to the gray granite outcroppings, while its heat transfer capability facilitates sky observation by minimizing temperature differential distortion.

As a counterpoint to the exterior and its context, the interior is lined with fir plywood, creating a haven of refuge and warmth from the harsh surroundings. The first floor is comprised of a research office, sleeping bunk, and warming room, and is super-insulated to prevent interior/exterior temperature differentials from creating heat eddies that would impede astronomical viewing. A helical stair leads from the cantilevered entry canopy to a fissure in the cladding that opens onto the exterior observation deck. Continuing, the stair arrives at the observatory’s primary viewing platform inside the faceted turret, its interior characterized by high ceilings, a larger telescope, and a camera array. A single person can rotate this turret by hand with an assembly typically used in high-precision manufacturing facilities, and a hand-cranked sliding hatch opens the telescope to the sky. A rift in the zinc cladding creates a corner window, framing Polaris when the turret is locked into the southern cardinal position.

The observatory is one of the most complicated jobs we have done to date. Foard Panel earns jobs like the observatory through our confidence that we can deliver even the most complex and innovative designs. The first and most important step of the process is creating a 3D model that coordinates between the steel structure, the foundation and our Structural Insulated Panels (SIPs). The first steps are to create a 3D model in AutoCAD and make sure it matches the designers’ intent and the steel fabricator’s drawings. That model allows Foard Panel to detail the cuts for the joints and all the various angles for each panel. The cutting is all done in the shop where we can contain the mess and get the best precision. Because the building is not square nor plumb, the placement of the steel and the foundation is difficult, and getting our panels’ placement correct is critical. In order to layout the panels’ starting point our lead designer and crew leader visited the site with the laptop and model to compare the as-built foundation and steel placement with our model. The design called for exterior insulation on the foundation so the wall panels starting point was not the edge of the concrete. The walls were not plumb nor did they all have the same angle, so the amount that the panels overhang the concrete is slightly different on each surface. Very high accuracy was necessary to make the angles work and allow the dome to spin freely. The keys to success on this project were accurate 3D models, precision of fabrication, and attention to detail in the layout of the sill. The Gemma Observatory required much more planning than than any other building of this size, but the careful attention to detail resulted in a spectacular piece of functional sculpture.