Stanley Hempcrete Extension

Wangal, Kameygal & Beddagal clans of the Eora people,
Marrickville,
NSW
This home will be open for in-person tours on the 17th May 2026

About this home

We demolished the old extension at the rear of the house. We include additional living space at the rear with a new deck and louvred roof.

New First Floor addition to include Rumpus room, Bathroom and Master bedroom with green roof.
All new external walls are 90mm timber framed with hempcrete and insulated timber framed floors.

Structurally insulated panels for the roof, double-glazed windows, native garden and edible garden. Washing machine and all toilets connect to the existing rainwater tank.

The main aim of the renovation is to create a more thermally comfortable home in natural materials that would also benefit us from the health benefits of using hemp – reduced risk of mould and breathable finishes.

Q & A

What motivated you to build or retrofit sustainably?
We wanted to improve our connection to the outdoors by providing adjustable out door living solutions. We needed additional space for a family of 4 and included a multipurpose area for everyone to use
We love the Hempcrete walls for the way they feel for acoustics and texture.I also feel reassured and knowing that the hempcrete walls are vapour permeable and that deep inside the walls are not rotting like our previous extension.I am also glad that it was a monolithic system which reduce our need for a complex wall of insulation, membranes and how to solve the the thermal bridging in standard construction
I wish we had chosen UPVC Windows and doors or pushed for thermally broken aluminium.We chose double glazed aluminium and we regret the thermal bridging that occurs through the frame and the condensation we have on the frames in winter.Knowing what I know now I also would have moved the frames within the insulation layer but having the frames closer to the external edge has meant wonderful deep reveals.
I would go the next step and install a HRV system.
Back to 2026 Homes
Type: Standalone house/townhouse
Project: Renovation or extension
Designer: Tracy Graham Connected Design (Owner)
Builder: Nick Sowden - Sowden building
Size: 144m²
Bedrooms: 3
Bathrooms: 2

Sustainability Features

Building Materials & Envelope

Draught-proofing/air sealing
High-performance insulation
Double or triple-glazed windows
Sustainable or low-impact materials
Recycled or reused materials
Other

Heating, Cooling and Ventilation

Passive heating/cooling (north-facing glazing, cross ventilation, thermal mass, shading, etc.)
Ceiling fans
Heat pump (reverse-cycle) heating/cooling

Energy and Appliances

Rooftop solar PV
Battery storage
Energy monitoring/smart home systems
Efficient lighting (LED, daylighting, solar skylights)
Heat pump hot water
Electric cooktop - induction/ceramic

Water & Waste Systems

Water-efficient fixtures
Rainwater tanks

Landscape & Biodiversity

Native garden
Edible garden

Climate Resilience

Flood

Accessible & Flexible Design Features

Design for flexible use
Share this home:

Related Homes

Home tours delivered to your inbox

Step inside sustainable homes across Australia and get practical ideas you can use in your own