S1 Columbia City Backyard Cottage


4720 S Dawson St
Seattle WA 98118

Saturday Only, 11am - 5pm

Site Description

Water Conservation, Energy Efficiency, Indoor Air Quality, Materials Efficiency, Design Innovation

The owners of this home lived here for about twenty years before deciding to build a DADU for a home based business. Their “must-haves” for the project included: Two levels with a secure garage that could be used as storage; an upper level flooded with daylight for creative work; building green was also important, so we focused on energy efficiency, sustainably-manufactured products, easy maintenance, and durability.

On this project, we used only formaldehyde-free and low-VOC products including: paint, Boral siding, and cellulose insulation. Cellulose insulation is essentially shredded, recycled newspaper that is treated with borate to keep insects away. We insulated the walls and ceilings beyond code. Along with tight air sealing we installed a spot ERV for whole house ventilation. We also installed fiberglass windows for durability and energy efficiency as the seasons change.

We chose a passive solar design that would heat the home efficiently in winter, and we also designed cross-ventilation to keep it cool in the summer. The heating system is sized appropriately using Ducoterra electric heating panels from Mighty Energy Solutions.

Nearby in Seward Park, there is a local year round parrot population who love to hang out in the cherry tree between the house and the backyard cottage. The tree also provides shade to the cottage and its deck in the summer. Other quick specs are: we used recycled cabinets from Second Use, Eco-Timber floors and there is on-site management of storm water.

Initially, the owners are renting out the space on short-term basis to recoup some costs, and then will use it for their work. At another point in time it could become a longer term rental. We were glad to construct a building that can have many uses for the owners over a long period of time. Designed and built well, DADUs will be here for years to come. They have the flexibility to fit the needs of the owners as the needs in their lives change over time.