Sapling House Lilyfield, New South Wales home photos, NSW interior, Australian modern property

Sapling House in Lilyfield Sydney

11 March 2025

Architect: Anderson Architecture

Location: Lilyfield, Sydney, NSW, Australia

Photos: Tom Ferguson

Sapling House, Australia

Sapling House represents the pinnacle of sustainability in construction, operation and livability. Designed to achieve the prestigious Passivhaus Premium certification, Sapling is an architecturally striking home for a growing family, which through the implementation of Passivhaus principles and the installation of solar panels produces more energy than it demands. It provides year-round thermal comfort for its inhabitants, while preserving the indoor-outdoor lifestyle they treasure.

Originally designed around two mature trees- a Jacaranda and a Cheese Tree- the unexpected felling of the Cheese Tree due to structural defects has made way for the planting of a new sapling in its place. Sapling itself echoes this transition, breathing new life into the site and serving as an example of an alternate, more efficient means of building, growing and thriving in the inner west suburbs of Sydney. Oriented to the north, Sapling encircles the site’s existing Jacaranda, capturing and controlling sunlight and daylight access through passive design means and high performance windows and glazing. Operable glazing throughout the ground and first floors of the home allow for passive ventilation and cooling when conditions allow, while a high level of airtightness and a heat recovery ventilation system (HRV) provides ample fresh air when conditions necessitate the closing of windows and doors.

Sapling’s Cross-Laminated Timber (CLT) structure, wrapped in woodfibre insulation and Weathertex and Abodo cladding ensures that the sustainable ethos of this dwelling continues to its core, resulting in a negative Global Warming Potential of approximately -0.03kg CO2 eq. Sapling’s CLT core is accompanied by high performance and low impact products, materials and finishes including low VOC paints, benchtops utilising recycled materials, cork flooring, cork and rubber stair lining, recycled timber window reveals and carbon neutral concrete. The home provides a sanctuary for its inhabitants; a healthy home that supports their health and well-being, while minimising its impact on the environment.

The initial brief was for a major renovation or to create a new home on an existing site in the inner west. Originally occupied by a small weatherboard cottage, the clients were fast out-growing the space they had and found the home to be quite uncomfortable thermally. Views of the city skyline available from the site were to be captured and capitalised upon, and the existing mature trees were to inform the design. Sustainable initiatives such as solar passive design were to be employed to greatly reduce the home’s dependency on air conditioning, and as much water and electricity as possible was to be produced onsite. A new pool and rear deck were to encourage indoor-outdoor living while engaging with the existing Jacaranda tree in the rear garden. Additionally, low and 0-VOC products and finishes were to be utilised wherever possible within the home.

Sapling’s design has been determined through a combination of traditional solar passive principles and informed modelling provided through the Passivhaus certification process. Achieving Passivhaus Premium performance, the home is predicted to remain comfortable and generate surplus energy over its lifetime. The well-insulated walls, floor and roof work in tandem with the high performance glazing to maintain stable conditions indoors without a reliance on air conditioning. The materials chosen and their detailing have been specified to endure, and the home’s 20.88 pkW solar panel array and Tesla battery have been installed to ensure that the home is as self-sufficient as possible over the long term, relieving pressure off the grid. – Alexandra Woods, Project Architect

Anderson Architecture was founded on an ethos of creating sustainable and inspiring architecture. To attest to this, the firm now has two in-house certified Passivhaus designers, and Passivhaus knowledge is freely shared amongst its members, Passivhaus principles, alongside passive design principles, forming the basis of each project’s design.

Anderson Architecture has always valued and practiced sustainable design, acutely aware of architecture’s environmental, health and wellbeing and social impacts. It is also a signatory of Architects Declare Australia and seeks through its projects to both advocate for the health of the built and natural environments. Sapling is one such development which demonstrates the sustainable ethos of the firm.

Achieving the prestigious Passivhaus Premium certification, the home has extremely low heating, cooling and energy demands. Through its 20.88kW solar array, it produces 380% of the energy it needs to run, achieving a carbon negative status in terms of its operation. It is also carbon negative in its construction, employing renewable materials such as CLT and woodfibre insulation, thereby achieving a global warming potential of -0.7 KG of CO2 per square metre per year over a fifty year lifespan.

Sapling easily surpasses its BASIX minimums, requiring only 14 kWh/m².yr for heating and 8 kWh/m².yr for cooling as demonstrated by its Passivhaus modelling. Anderson Architecture employs post-occupancy monitoring of its Passivhaus and high performance homes through the implementation of Indoor Environmental Quality monitoring, and in so doing learns from each project’s performance- Sapling is no different.

IEQ monitors have confirmed that internal temperatures remain relatively stable throughout the day and year, while client feedback has confirmed that they no longer pay electricity bills.