Two young, determined engineers have realised their vision of a Zero Energy home that also embraces great design and style. (And that’s just the beginning of the home’s sustainability credentials.)
Jo Woods and Shay Brazier, two young and determined engineers, brought their vision to life of a home that's energy efficient, while embracing great design and style. Their two-story, three-bedroom home generates all the energy needed to run the household. With Jo and Shay's philosophy everything in their home is well-considered and low energy. It produces energy via solar hot water and photovoltaic panels and incorporates energy efficiency measures to minimise consumption. They trade electricity with their retailer via a grid-connection to balance out seasonal fluctuations in available solar energy.
In addition to the Zero Energy goal Jo and Shay’s home incorporates an end-to-end system of water efficiency measures, low-toxicity materials selection, and recycled timber for flooring, structural beams, stairs, and kitchen cabinetry. The house builds on skills and experience gained throughout their professional careers.
Jo is an associate at eCubed Building Workshop specialising in Environmentally Sustainable Design, where she models building thermal performance and specifies sustainable construction materials.
Shay is head of Design and Innovation at SolarCity where he leads an engineering team that designs solar hot water and photovoltaic solutions for residential, commercial, and government projects. To achieve Zero Energy, the design process integrated the architectural design with Jo and Shay’s engineering input. Kendon McGrail and Jennifer Hanson from A Studio Architects designed the house around the thermal performance and solar requirements that Jo and Shay specified. Construction was managed by Nye O’Shannessy Building.
Shay Brazier says, "What's typical is a sequential process, where the client briefs the architect, who instructs the builders and specifiers. In our case we worked together at every stage of the journey, tweaking the design to be able to incorporate energy savings to such a great extent." Throughout construction dozens of sensors were embedded in the fabric of the building to report energy generation and consumption, water usage, temperatures, and humidity. Beginning in September 2013, Jo and Shay will start to publish data from these sensors on the project website to demonstrate the performance of the house.
They will also be detailing construction and on-going energy and water costs to illustrate the economic case for Zero Energy. Jo and Shay decided to build a Zero Energy House not only for themselves, but to prove that it is a viable housing solution for New Zealanders. Their design decisions, building methods, and systems and materials selection have been documented at Zero Energy House to make it easier for other people to launch similar projects.
Summary of the key features:
- Two-storey, three bedroom house in Point Chevalier, Auckland.
- Building envelope designed for passive heating and cooling.
- Solar photovoltaics. 4.16kWp array consisting of 88 x solar integrated solar roof tiles (SolarCity).
- Solar water heating. 8 x Artline hot water collectors (SolarCity).
- Framing. Modified wall framing to allow for double-layer of insulation.
- Insulation. Wall and roof insulation 50% above building code (GreenStuf).
- Windows. Dual-tilt frames (Heirloom Joinery) double-glazed with argon-filled ClimaGuard N70 (Metro GlassTech).
- Green roof. Non-bitumen heat-sealed membrane (Viking Roofspec).
- Lighting. LED throughout the home (Philips).
- Paint. Environmental Choice-certified (Resene).
- Nearly 100% PVC free. Alternative pipe and wiring products used to minimize PVC onsite.
- Cladding. Non-treated Macrocarpa (MacDirect).
- Recycled timber. Structural beams repurposed from old boat beams, kitchen island bench made from decking timber, upstairs flooring from recycled rimu, kitchen cabinetry from recycled kauri from an old Auckland pub.
- Non-potable water supply. 5,000 litre underground rainwater tank.
- Water distribution. Low-energy pumps for water from rainwater tank to house, and to move water around the solar water heating system (Grundfos).
- Water demand. Low-flow Tahi taps and Kiri showerheads throughout the home (Methven).
- Water disposal. Grey water recycling system installed (WaterLillee) but not yet switched on…waiting for changes in Auckland City’s wastewater guidelines to permit it.
- Monitoring. 40 sensors throughout the home that provide remote performance reporting via smartphone.
Waste. Separation of all waste materials during construction and disposal through recycling channels where possible.
Images courtesy of Todd Eyre Photography.