Making the most of a small footprint, this accessory dwelling unit uses two partitions thickened with custom millwork to subtly divide an occasional guest bedroom from a daily-use office. The depth of these divisions provides space for a semi-open closet, bookshelf, and built-in desk. Plywood cladding unifies the geometries of the interior, and a full-height curtain temporarily divides the space as needed. Light fills the room through tall clerestory windows that reach above the neighbor's fence, while a large sliding glass door opens onto a low-lying wood deck and a drought-tolerant garden at the front of the unit. With economy in mind, the detailing of the ADU brings a contemporary aesthetic to off-the-shelf construction, from wood cladding to corrugated roofing.