steel slats filter sunlight into robbie walker's sawmill treehouse

A Client-Driven Approach to Design

Sawmill Treehouse, a recently completed architectural project by Australian designer Robbie Walker, exemplifies how great design emerges from a strong collaboration between architect and client. The homeowner’s vision was simple — a compact residential retreat to share with family and friends. Rather than focusing on interior finishes or material selections, the client prioritized the site’s natural elements, sharing images of the trees and landscape instead of tile samples or countertop options. This approach underscored a design philosophy rooted in the surrounding environment rather than conventional luxury.

The treehouse is located at the beginning of a gully, where street water is discharged. The site offered one obvious flat area near the boundary, surrounded by towering trees. Instead of situating the structure on the flat land, Walker chose to elevate it among the trees, keeping it above the water and integrating it into the forest canopy. Four stilt-like columns, reminiscent of tree trunks, support the structure, while a facade of slatted steel panels allow light to filter through in an organic pattern, mimicking the effect of leaves. These slats also help regulate temperature, keeping the steel-clad building cool in the strong Australian sun.

images © Tasha Tylee

Compact Living in the sawmill treehouse

Designed by Robbie Walker as a minimal yet functional dwelling, Sawmill Treehouse includes just one bedroom, one bathroom, and an open kitchen and living area. The designer‘s decision to elevate the structure provides a unique treehouse experience while allowing for a covered garage beneath the living space. This garage, taking advantage of the site’s natural flat section, also houses a laundry and an outdoor kitchen concealed within the structure.

Due to the site’s high bushfire risk classification (BAL 40), all external materials needed to be non-flammable. This requirement led to the use of steel cladding, which also presented the challenge of excessive heat absorption. To mitigate this, Walker designed a system of steel slats that shade the building while allowing airflow to move through the space between the slats and the walls, reducing heat buildup and eliminating the need for air conditioning.

Sawmill Treehouse by Robbie Walker was designed as a compact retreat focused on nature

robbie walker’s Model for Sustainable Design

The client’s decision to build small, despite having ample space, reflects a commitment to thoughtful, sustainable living. In a market where real estate agents push for larger homes to maximize resale value, and where banks may undervalue compact homes in rural settings, resisting the pressure to expand was a courageous choice. The additional planning and permitting requirements for a small home do not necessarily translate to cost savings, making this project a testament to prioritizing quality over quantity.

While timber interiors were chosen for their sustainability, and steel was selected for its recyclability, the project’s most significant environmental impact comes from its restraint. By resisting the temptation to build beyond necessity, Sawmill Treehouse challenges the prevailing ethos of more-is-better, demonstrating that efficient, well-considered design can be just as impactful as material choices. In an era of increasing environmental awareness, this project stands as an example of how architecture can align with values of sustainability and thoughtful land use.

the client prioritized the site’s trees and landscape over interior finishes and materials