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 the first Passive House-certified home in San Francisco and officially achieved Net Zero Energy Building Certification in June 2014. The International Living Future Institute comprehensively evaluates buildings for certification in terms of Growth, Energy, Rights to Nature, Inspiration + Education, and Beauty + Spirit. Building features
A simple form that is efficient to construct and enables flexible interior spaces. An easy-to-install exterior rain-screen system designed and prototyped by David Baker Architects. Salvaged and new metal shingles quickly slide into the custom metal clips and can be quickly moved or replaced. Planter box panels add a playful functionality and are relocated throughout the seasons. 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 92% efficient heat-recovery ventilating (HRV) system that captures heat generated by day-to-day use (appliances, computers, people) and warms incoming air, eliminating the need for conventional heating. On warmer days, the high level of insulation and building mass greatly minimizes heat gain. Charred-wood siding made from maple flooring salvaged from a previous adaptive re-use project. A mix of advanced LED fixtures, most dimmable, to greatly reduce the total wattage used for lighting A vegetated roof featuring drought-tolerant garden (designed by David Fletcher of Fletcher Studio), composting, urban agriculture, and a “bread-box” solar water heater. A three-kilowatt photovoltaic system, mounted on a custom fabricated frame by Henry Defauw, covers the stair and generates more energy than the cottage uses.
Interior features
An open two-level plan that blurs boundaries to achieve a streamlined livability. Interiors aesthetically aligned with the main flat, yet distinct in their materials and finishes. Salvaged wood floors (the same used for the charred siding) are simply treated with a VOC-free, easy-to-maintain monocoat flaxseed oil. Custom cabinetry made from the cottage's construction waste, leftover wood, and the previously salvaged wood floor. Plaster walls have no VOCs, require limited maintenance over time, and increase the building mass (which is key to passive heating/cooling) Custom daybed and desk by David Pierce, Ohio Design. Custom bed designed and made by David Baker. Carefully sited windows frame views without compromising privacy. A light monitor enhances light and natural ventilation, and provides access to the roof. Energy and space-efficient appliances.
