Boulder House
Willow, NY
An older single professional who spent most of her life in New York City approached us about creating a four-season weekend house on a large parcel of gently sloping, forested land near Woodstock. The site was originally part of a larger parcel that was used for sheep farming for several centuries but the sole signs of previous development were a series of dry bluestone walls at its north and south edges and the loose bluestone foundations of some kind of small two-room barn or pen, which remained more or less intact. These stone assemblies, along with an interest in other local 19th c. barns that still stand, drove our brief to work with the regional vernacular — simple, gable-end buildings in wood, rectangular pens and sties, sheet metal shacks and bluestone walls.
The site opened substantially to the east as it tumbled down hill to a small stream. The needed addition of a septic field lower than the new house stood to further open this view and keep new trees from blocking it. For this reason, we chose to site the new building near the lot’s center where the topography was steepest, allowing us to depress the structure eight feet into the ground, hiding it from the road uphill while allowing for broad views and a walk-out porch on the downslope side.
As a counterpoint to the long views east, we established two more intimate encounters uphill. First, we wrapped the building around a particularly beautiful boulder deposited by glaciation millennia ago, allowing up-close views of its surface and shadow-play at eye height from the living room and the bed. Second, we extended the perimeter of the retaining walls to create a sunken rain garden adjacent to the bathroom, providing it with light and air, creating a private space for an outdoor shower and giving all-season views of cold-hearty water lilies from the tub.
The house is laid out on a 4’ grid to allow for the economic use of materials and to facilitate alignments across the plan. The client’s brief required a substantial amount of space for daytime entertainment without compromising a sense of intimacy during nights spent alone. The central double-height barn form contains this full spectrum: the large dining porch opening to views on the downhill side, the kitchen buried in the topography to waist height and the small bedroom tucked in deep below a loft.
The house is built around a series of retaining walls that step up in 2’ intervals every 16’. These walls are exposed to the interior, registering the variable depth of the surrounding soil and forming all windowsills. To the exterior, these walls are clad in hand-chipped bluestone, reflecting the surrounding dry stone walls. Atop the retaining walls sits a lighter wood structure that is wrapped in a cedar rainscreen from sill to ridge, integrating water management.
A central goal was to greatly exceed the code minimum thermal performance requirements for this very cold climate. Framed walls and ceilings employ a combination of batt insulation and continuous rigid exterior insulation. Roof-to-wall transitions are kept tight in order for insulation and waterproofing to be run continuously over them. Foundation walls were built from hollow insulated Korfill CMUs, greatly increasing their thermal resistance in a scheme where they crossed from subterranean to exposed.
Active heating costs were a great concern for the client. We were able to engineer the large double-sided hearth that separates the living room from the kitchen to channel its heat under the raised floors of the main house, supplying it through registers in the kitchen, bedroom and bathroom. The hearth itself can be closed off with thermally insulated glass doors, receiving make-up air from the exterior in order to burn efficiently and safely all night long.