An ADU on land others said couldn't be built on.

The property has an unusual history. Several decades ago, a landslide on the site damaged the original main house, which was subsequently picked up and relocated toward the edge of the lot, further from the unstable ground. The house has stood safely there ever since, but the rest of the property was never touched again. The landslide remained on record, and the largest and most usable portion of the site sat empty and underused for decades. Any engineer approaching the property has to reckon with that history.

When the owner asked Studio Graf to explore adding an ADU, the first geotechnical engineer consulted advised against building in the affected area at all. Rather than accept that as the final answer, Studio Graf sought a second opinion. A specialist landslide geotechnical engineer took the project on, and together the team developed an engineered solution: a series of retaining walls, with the lower wall built as a stitch pier system anchored deep into bedrock to arrest the downslope movement of the hillside.

The walls do two things at once. They carve a level building terrace out of the slope, and they physically stabilise the ground itself, making future landslides significantly less likely across the affected area. The ADU foundation sits on its own grid of piers within that stabilised ground.

The pavilion that resulted is a compact contemporary structure with a clear organising idea: an open interior that can adapt to whatever the owners need it to be, wrapped in a generous covered outdoor room that serves both the ADU and the main house. Inside, the plan is deliberately loose and flexible, ready to function as a guest suite, home office, gym, entertainment space, or rental. Outside, the covered patio brings together an outdoor kitchen, fire pit, and jacuzzi, and becomes the primary shared gathering space for the property.

Materially, the pavilion is anchored by vertical cedar siding that echoes the cedar detailing on the main house, giving the two buildings a shared architectural language despite their differences in scale and era. A dark steel roof frame extends beyond the enclosed volume to define the covered outdoor room, drawing a strong horizontal line across the site and framing views out toward the newly planted vineyard on the terraced slope beyond.

Beyond the architecture itself, the project made a substantial portion of the property genuinely usable for the first time in decades. What began as unbuildable land now supports a contemporary pavilion, landscaped terraces, and a working vineyard, and the value of the property has grown accordingly.