The Waterfall House, Rhinebeck, NY 12572

Between roughly 1710 and 1870 the Landsman Kill powered about fifteen mills at twelve waterfalls along a short run of water in Dutchess County, cutting lumber, grinding grain and cornmeal, pressing oil and plaster, weaving textiles and, by the end, making paper. One of those drops is on this land. The water crosses a dam built in the early 1900s and falls some sixty feet into a basin of rock, and the dam, which once generated the electricity for an earlier house here, still holds the private lake that sits above the compound.

Steve Mensch taught in Cornell's Department of Design and Environmental Analysis and ran Mensch Design and Construction before he came to the Hudson Valley; his 1978 house over an Ithaca gorge was bought by Carl Sagan in 1981. He found this site in winter and understood it immediately. Before he drew anything he moved a cot and a drafting table into a small cottage on the land and stayed through a full turn of the seasons, and the vertical, castle-like scheme he had first imagined gave way to what stands now: four wood framed pavilions under copper roofs, set at angles on and around the rock, linked by covered walkways, a wooden walk across the lake and a suspension bridge over the water.

The frame is concrete and timber and the interiors are almost entirely wood, built in and fitted room by room. The main house sits at the water's edge with its kitchen, dining room and living room in one open plan, and the living room's glass walls retract, so the room opens onto the falls; a patio runs out to the lip of the drop. A two story studio and two guest houses stand apart in the trees, close enough to walk to under cover and far enough to be their own buildings. Six bedrooms and five and a half baths across 6,798 square feet, on 21.28 acres near the old Grasmere estate that Janet Livingston Montgomery began after the Revolution, a short drive from the village of Rhinebeck.

The mills are gone from the Landsman Kill. The drop they were built for is in the living room window, and on the days the glass is pulled back it is in the living room.