Castlemaine Hybrid:House — A Net Positive Passive Design for the Australian Climate
Nestled against a 12-metre siltstone rock face in Castlemaine, the Hybrid House is a site-specific response to challenging terrain and BAL 29 bushfire constraints. The L-shaped design maximizes northern solar access, protects from southerly winds, and frames panoramic views toward Mount Franklin. A cantilevered balcony floats above the tree canopy, blending architectural drama with functional outdoor living.
Constructed using Outlier’s Hybrid Home methodology, this project bridges traditional Australian building practices with Passive House principles. Developed through extensive research and testing, the method achieves low-energy performance—meeting Passive House standards at reduced cost—through airtight construction, continuous insulation, and thermal bridge–free detailing.
The all-electric home operates as a net-positive energy dwelling, powered by a 6.6kW photovoltaic system with battery and EV readiness. Systems include heat-pump hot water, air-source heating and cooling, induction cooking, and low-energy fixtures. A 10,000L rainwater tank, native drought-tolerant landscaping, and a 90% waste recycling rate further reinforce the home’s sustainable ethos.
Inside, a continuous Heat Recovery Ventilation system ensures superior indoor air quality, maintaining 18–23°C and 50% humidity year-round. This system filters smoke, pollen, and pollutants, creating a clean, comfortable, and healthy living environment—even during extended absences. Real-time sensors monitor energy production, air quality, and thermal performance, allowing the home to learn and adapt over time.
Currently awaiting 10-star NatHERS verification, Castlemaine Hybrid House sets a new benchmark for sustainable residential design—where innovation, comfort, and environmental responsibility are seamlessly integrated.
Key Features:
Site-responsive L-shaped design shaped by a 12m northern rock face and BAL 29 constraints
Maximised solar gain and panoramic views toward Mount Franklin
Hybrid Home methodology combining Passive House principles with standard Australian construction
Net-positive all-electric energy system with 6.6kW solar array and battery/EV readiness
Heat pump hot water, induction cooktop, and high-efficiency air-source heating and cooling
Continuous thermal insulation, airtightness at 0.6 air changes/hr, and thermal bridge–free structure
Heat Recovery Ventilation system providing filtered, balanced indoor air quality
Monitored indoor conditions maintaining 18–23°C and ~50% relative humidity
10,000L rainwater harvesting system and drought-tolerant native landscaping
90% construction waste recycled and FSC-certified prefabricated timber structure
Low-VOC materials and continuous monitoring via sensor network for performance optimisation
Castlemaine Hybrid:House exemplifies how thoughtful design and research-driven innovation can create a beautiful, low-energy, and resilient home that enhances wellbeing while contributing positively to the environment.
