To create a small guesthouse and rental unit on a steep hillside property in Marin County CA, Mork-Ulnes Architects took the foundation from an old garage and built a new Accessory Dwelling Unit (ADU) on the exact footprint of the old garage.
The building’s sharply angled roofline mirrors the slope of the site and gives a high clerestory window light above the cabinetry wall, while a playful flip in the roof provides a punched window from the loft viewing the trees. Cement board was used to provide a fire resistant cladding in the wooded hillside, and also for ease of maintenance.
Due to the incredibly steep hillside, a deck was added on the front of the ADU to add more usable exterior space to take advantage of the mild California climate, essentially doubling the ADU’s usable area. Designing for the utmost effective square feet (411 sq.ft. / 38 square meters), flexible programming was deployed: a rolling kitchen island can be moved in or outside when space or utility is needed, and a murphy bed hides in the wall during the day and folds down at night for sleeping.
The loft space, with a window out towards the trees as well as down to the living space, is accessed by a ladder that tucks in to the wall. The bathroom is split into two smaller rooms – a toilet/sink and a forest-green tiled shower room with a glass door out to the tree covered hillside. The ADU is currently being used by the owners as their vacation cabin while their main house is being renovated.
