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Architects: Miller Hull Partnership
- Area: 400 ft²
- Year: 2019
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Manufacturers: Blakely Island Timber, Quantum Windows & Doors, Sun Valley Bronze, Watermark Elements
Text description provided by the architects. Light on the land and no more than necessary – these were the first principles that guided the development of a 400-square-foot bunkhouse adjacent to the iconic Decatur Island Cabin designed by Robert Hull, Miller Hull’s late founding partner, in 1986. A deep respect for the natural condition of the site drove all decisions made by the design team. By elevating the enclosed volume above the site, the building massing amplifies the sloping topography while minimizing site disturbance. Foundations were reduced to six-point loads puncturing the natural landscape. A timber exoskeleton pays homage to the neighboring cabin while supporting a simple “sleeve” of interior space. These rooms are arranged with sensitivity to exposure and views, allowing the bunkhouse to sit near the cabin while maintaining privacy.
The steep site presented significant challenges including the inability to access the immediate building area with any heavy equipment. A narrow 500-foot trail through the woods connects the end of a gravel road to the site, through which all construction materials were carried by hand. Building components were sized based on the ability of a three-person crew to maneuver them along the trail.
Budget constraints drove a tight construction timeline and eliminated any unnecessary trades. The small crew lived onsite during a good portion of construction to reduce transportation costs and the environmental impact associated with building on a remote island. The design team embraced these challenges as the defining constraints of the project, allowing them to shape a simple yet potent intervention.
The extensive use of wood for structure, cladding, and interior finishes was intuitive given the region’s availability of renewable and responsibly harvested timber. All solid timber elements were sourced from FSC-certified forests including some from a sustainably managed forest on neighboring Blakely Island. The carbon sequestration associated with the extensive use of wood allows the project to vastly offset the upfront embodied carbon impact used to manufacture other materials like concrete, steel, and insulation.
The balance of greenhouse gas emissions to sequestration during building product manufacturing and transport is roughly equivalent to taking 2 passenger vehicles off the road for 1 year. When considering the global warming potential of all building components (foundations, structure, exterior, and interior finishes) calculated through the end of life of the structure, the project is projected to emit around 50 kgCO2e/m2 – a near-record low for Miller Hull projects.
In lieu of high-tech sustainability measures, the project works with careful siting and orientation, reducing energy consumption through passive means. Roof overhangs on the south and west are tuned to mitigate solar heat gains while the northern clerestory welcomes so light into the bathroom and study. Operable clerestory windows assist in natural ventilation and allow the Bunkhouse to take advantage of onshore breezes in the summer months.
