This Australian Passive House home is such a stunning departure from a simple rectangle and a great example of how complex forms can still be extremely energy efficient. It goes to show what energy modelling at design stage can achieve. Congratulations to all our Australian Passive House colleagues who brought this project to fruition back in 2019.
The design didn’t get away with these pavilions and courtyards because it’s in the tropical north. The house is located in a rural area popular for weekend getaways from Melbourne. The mean maximum winter temperature is 7.8C; by that measure, it’s the coldest town in the state of Victoria. Snowfall is a dependable winter occurrence.
Reproduced below is the case study published in Passivhaus in Australia by APHA in 2020. I served as editor and am happy to find it is now available again as a download on the Envirotecture website*. You can find more information about the architectural design behind Owl Woods on Re-thinking the Future.
This pioneering project blends biophilic design and Certified Passivhaus performance to create an unique and beautiful home. Owl Woods is located in Trentham in regional Victoria at an altitude of 700m. The challenging climate ranges from snow in winter to summer temperatures of 40°C.
For the new home to be climate-responsive, comfortable, sustainable and energy- efficient, the decision was made to design and construct the building to the Certified Passivhaus standard. Generous visual and physical connections to nature, natural light and materials are integral to the design, whilst the contemporary pavilion-style layout creates diverse indoor environments.
However, this shape brings its own challenges to the project. Simple, rectangular forms can more readily achieve the Certified Passivhaus standard. Owl Woods’ separate wings and integrated courtyards increase the external wall area but this could be accommodated by increasing insulation values and using triple-glazed high-performance windows. Modelling the energy performance of the building at the design stage shows how these different elements interact and ensures the design will perform to the required standard.
Owl Woods is proof that creatively designed homes can meet the certified Passivhaus performance standard; Passivhaus buildings need not necessarily be simple forms.
“High on our priority list was sustainability. The idea of a house with good solar orientation was suggested and this soon developed into a full blown Certified Passivhaus.” —Owl Woods homeowner
- Sustainability Awards 2019: FINALIST Single Dwelling (New)
- ArchiTeam Awards 2019: WINNER Sustainability Medal
- HOUSES Awards 2020: SHORTLISTED Sustainability Category
- Design Matters National Awards 2020: WINNER Residential – New House Up to $500K-$1M
- BDAA Awards 2020: WINNER National Design Excellence Award
- BDAA Awards 2020: WINNER New residential buildings 251–350m2 and >$2500/m2
Passivhaus metrics
| Certified | 2019 Passivhaus Classic |
| Heating Demand | 15 kWh/(m2a) |
| Heating Load | 11 W/m2 |
| Treated Floor Area | 170 m2 |
| Form Factor | 3.9 |
| Air Leakage @ 50Pa | 0.5 ACH |
Project team
Architect/Designer Talina Edwards Architecture (now part of Envirotecture)
Passivhaus Designer/Consultant Luc Plowman, Detail Green
Builder Enerhaus (previously Craftsmen Quality Builders)
Passivhaus Certifier Clare Parry
West elevation
South elevation
Photo by Tatjana Plitt
Photo by Tatjana Plitt
Photo by Tatjana Plitt
Later photo showing landscaping grown in by Jane Macrae
*Envirotecture directors Andy Marlow and Talina Edwards were instrumental on the APHA committee that oversaw this book’s development and staff member Mia Radic compiled the many case studies.
PS Another Australian project remarkable for its complex thermal envelope is Heathmont, below. Find it on pp 58-59 of Passivhaus in Australia, along with an illustration on the opening pages.
