Zero Cottage is an investigation of compact, sustainable urban development and a contemporary approach to living and working. The cottage is composed of a 712-square-foot living space set over a 430-square-foot workshop. It pairs with an existing building to complete a flexible, mixed-use compound that also includes a two-bedroom flat, studio apartment and storefront space.
The free-standing addition presented an opportunity to explore advanced sustainable design, construction techniques, materials and technologies, with a goal of achieving Passive House and Net-Zero Energy certification. The cottage is certified LEED for Homes Platinum. It is expected to be the first Passive House-certified home in San Francisco when certification is confirmed later this year. Net Zero Energy certification is expected after a year of actual energy use monitoring.
Building features
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A simple form that facilitates efficient construction while establishing open interior spaces.
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An easy-to-install exterior rainscreen system designed and prototyped by David Baker Architects. Salvaged and new metal shingles quickly slide into the custom metal clips and are easily moved or replaced. Playful planter box shingles, home to an herb garden, move with the seasons.
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Robust Passive House construction combining continuous exterior foam insulation, a near airtight membrane, and triple-glazed windows. The resulting air-change-per-hour rating of around 0.5 necessitates a heat-recovery ventilating (HRV) system that eliminates the need for conventional heating by recovering 92% of waste heat. On warmer days, the high level of insulation and building mass greatly minimizes heat gain.
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Charred-wood siding using maple flooring salvaged from a previous adaptive re-use project.
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A mix of advanced LED fixtures, most dimmable, that greatly reduce the total wattage used for lighting
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Vegetated roof incorporating used Ducati tires and container vegetable garden designed by David Fletcher, Fletcher Studio
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A 3-kilowatt photovoltaic system mounted on a custom frame designed and fabricated by Henry Defauw. The array, which doubles as an entry stair canopy, generates more energy than the cottage uses.
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Stormwater runoff from both structures is channeled to detention basins and allowed to slowly infiltrate the groundwater system.
Interior features
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An open, efficient two-level plan that makes the most of the modest space.
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Carefully sited windows framing views of the city without compromising privacy.
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A light monitor enhancing light and natural ventilation, and providing roof access.
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Interiors aesthetically aligned with the main flat, yet distinct in their materials and finishes.
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Recycled wood floors (the same wood used for the charred siding) simply treated with a VOC-free, easy-to-maintain monocoat flaxseed oil.
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Custom cabinetry by Kevin Clarke made from framing lumber salvaged from the existing shed structure removed from the site and construction waste.
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VOC-free plaster walls offering easy long-term maintenance (no repainting) and increased building mass.
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Custom daybed and desk by David Pierce, Ohio Design.
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Custom bed designed and made by David Baker.
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Energy-efficient, compact appliances.
Landscape and grounds
• Updated permeable and drought-tolerant landscape designed by David Fletcher, Fletcher Studio.
• Mural by artist Andrew Schoultz.
• "Why," a remnant of the "17 Reasons Why" sign, a former local landmark.
About the Shotwell Compound
The cottage continues the evolution of an urban site that predates the 1906 earthquake. The original compound comprised an upstairs flat set above a ground-floor grocery store, and additional living quarters in the rear yard. Today, the Zero Cottage stands in back, the studio apartment is rented through Airbnb, and David Baker and his partner, Yosh Asato, have launched StoreFrontLab, a community-focused cultural initiative that gives the historic commercial space a new public purpose, rooted in the neighborhood's contemporary culture. Over time, the flexibility of the compound's components will support a wide range of uses and configurations.
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20816 Shotwell Cottage Set 2011 July 08