Pepper Tree Passive House

Alexander Symes Architect

Pepper Tree Passive House is a small secondary dwelling to a young family’s home in the Australian Illawarra region. It is located on a steep site and elevated into the canopy of the site’s 60 year old Pepper Tree. Built to the international Passive House standard, sustainability is at the core ethos of the project – embodied between the natural material palette, high performance design and strong biophilic connection. The ambition of this project was to do more with less – while light touches to the existing home were made to improve its thermal performance, building the new secondary dwelling to the Passive House standard has created a future proofed refuge to escape to in future peak temperature days.

The two cantilevered wings of the detached studio each host a green roof. The northern wing comprises living, office, kitchen and breakfast bar and there is a curated view of Mount Kembla. Recycled sandstock bricks line the floor and wall area and direct sunlight from the northern highlight windows create a thermal battery effect in winter. The private southern wing contains the bedroom, laundry and bathroom and the floating deck between the two wings has been carefully scribed around the existing Pepper Tree, providing a meditative retreat immersed in the tree canopy.

From the project’s outset it was critical for the design to use both materials and landscaping in a way that strengthened the biophilic connection to the Pepper Tree, as well as regenerate the biodiversity of the site. Despite the small building footprint, it was critical to the project’s success that the site’s natural environment was disturbed as little as possible. The building’s two wings each host an extensive roof garden and collect excess rainwater for the dwelling and the Shou Sugi Ban timber cladding allows the building to blend into the landscape. Internally, timber products with no-VOC finishes were used, reducing total embodied energy while still providing a warm material palette.

Photography by Barton Taylor

Furniture: 55 Parrots. Fittings & Fixtures: Harvey Norman Commercial, Fisher & Paykel.