This is a new story-and-a-half, 2 bedroom, 2 bath backyard cottage in the Green Lake neighborhood. The owners wanted a detached accessory dwelling unit that, in the short term, will provide a place for the in-laws to stay during extended visits. In the long term it will act as a residence for the in-laws when they re-locate here from Hawaii. The ground floor bedroom can be accessed separately from the DADU, to act as a guest bedroom for the main residence. This is expressed on the outside with different cladding materials.
The structure maximizes the square footage allowed by the Backyard Cottage Ordinance, in an envelope that fits within the strict limits on roof height (20′ on the high side, 16′ on the low side), and required minimum ceiling height at the second floor stair landing. The owners wanted their cottage to be a simple modern structure, clad in a palette of durable, low-maintenance, natural materials. It has a shed roof, which expresses on the outside the loft configuration on the inside. The entry (west) facade addresses the outdoor space, with large windows that look onto the shared side yard/back yard, and that bathe the interior with natural light.
A large family room, adjacent to the kitchen, contains the stairs that access the second floor bedroom and bath. A stacked washer/dryer and the HVAC equipment are located under the stairs and landing. The heat is supplied by mini-split heat pumps, and a heat-recovery ventilator provides continuous fresh air. A fully insulated concrete slab, and a super-insulated envelope (with exterior rigid insulation, and rain-screen siding) keeps the heat inside.
The owners had a fairly tight budget for the project, but it was easy to meet it, given that it’s such a small structure. The cost per square foot might appear relatively high, but that’s the nature of small structures (economy of scale). Incidentally, the project was used as a case study in successfully arguing to the City that their method of determining the maximum roof height, on the low side of the structure, unfairly penalizes projects that opt to add more insulation than required by code.
Data: main floor: 540 s.f. upper floor: 255 s.f. total: 795 s.f.