Straw Bale Zero Net Carbon Craftsman
Hillsborough, California
We designed this Straw Bale, Zero Net Carbon home for long-time Hillsborough residents to downsize and comfortably and safely age in place. Our clients’ requests were for a traditional design, a very high level of sustainability and resiliency, accessibility and convenience for aging in place, and high acoustic separation from street and airport noise. Additionally, they hope that in meeting their own long term needs for their home, they will also provide a good example of practical and beautiful sustainable design.
The house will be a traditional Craftsman style cottage: gabled roofs with a face to the street; wide fascia boards with shaped tails; brackets; 7:12 roof slopes typical of many early Craftsman cottages; wide eaves; wide flat window and door trim; porch overhangs with Craftsman details; a shed dormer; a stone base tying the house to the ground at the lower level; stone further extending out into the landscape design. Exterior plaster will have the look of stucco on many original Craftsman homes.
We are working with a team of consultants at the forefront of sustainable and resilient building practices, for water capture and reuse, sustainable structural design, and detailed energy modeling and mechanical engineering to optimize all the systems of the house.
The main building system is straw bale, a carbon-sequestering material gaining in usage, and chosen for its many benefits: low embodied energy, low toxicity, very high insulation value, very high acoustic rating, high fire resistance with plastering, and beauty of its thick walls and deeply inset windows and doors.
Water will be captured for reuse from three sources: roof runoff, ground runoff, and graywater. Most of the equipment is hidden from view. Groundwater capture will solve an existing drainage problem in addition to saving a large amount of water year after year. Parking spaces are added along the street, alternating with planting beds fed by captured water. The garden will be designed for enjoyment of outdoor living space, a small amount of edible planting, fire protection, and a high level of sustainability.
The home will be all-electric, with all systems optimized to both up-front and long-term resource considerations. The roofing is Tesla solar tiles, tied to battery backup. The Tesla tiles were chosen in part because they have a visual scale that is more in keeping the with traditional style of the house than solar panels would be. The design incorporates simple passive solar principles. There will be a whole-house air filtration system with a heat recovery ventilator, for lowering energy use and protecting indoor air quality. Windows will have very high energy, acoustic, and impact ratings, while retaining the look of traditional wood divided lite windows.
The driveway is moved and the site is configured for accessibility. The top of the new driveway is almost level with the finished main floor, and also with the outdoor living space at the rear yard, for ease of use and accommodation of any future need for wheelchair access. Only a family room and utility space are located at the lower level, internally connected by a staircase, and externally connected by an accessible path.
Architect – Saikley Architects
Landscape Architect – Larman-Garro Landscape Architecture
Structural Engineer – Verdant Structural Engineers
Civil & Geotechnical Engineer & Water Consultant – Questa Engineering Corp
Energy & Sustainability Consulting – Beyond Efficiency
3d Renderings – Noa Younse
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“We worked with Alexandra on a major project with several challenges – building a brand new home on a small, sloped lot that required several variances. To add to that, we were first-time owner-builders. From the very beginning of the process at the design stage, Alexandra was easy to work with and very open to both incorporating our requests and needs while providing helpful insight and guidance. Her clear, consistent, and thorough communication got us through a complicated Zoning review process. She and her team helped us adapt in creative ways to ensure that we met Zoning’s requirements while still keeping the best parts of the design. We’ve been living in the home for several months now and absolutely love it! The best part for us about working with Alexandra, which is easy to take for granted but very significant in a long project like this, was her incredible professionalism, responsiveness, and trustworthiness. We never had any problem communicating and working with her over the course of our project, despite the other challenges and many different people involved. Thank you, Alexandra, for helping make a dream come true for us!” – Client