When Phorm Architecture + Design was asked to design a backyard extension for a young Australian couple, they were stepping into uncharted territory. Typical house lots in the suburb of Brisbane are long and thin, with traditional timber and tin houses that politely occupy the street edge, but leave largely empty spaces at the rear of the lot.

The backyards of these homes "tend to be overgrown, unruly spaces and are the domain of children and makeshift structures. The tree house is devised as an invitation to visit and engage with this distinct yet typically unchartered territory," says architect Paul Hotston.

Designed to be a "weekender in the backyard," the 452-square-foot tree house takes a grown-up approach to the classic children's cubby house.

The triangular shape comes from the owners' desire to not completely fill the backyard area, while also accommodating the stately, deciduous tree at the center of the space.

Project Credits:

Architect, Lighting Design, and Interior Design: Phorm Architecture + Design / @phorm_architecture

Builder/General Contractor: Marvel Constructions / Entony Lanca

Structural Engineer: Optimum Structures / Murty McKeague

Cabinetry Design/Installation: Sunshine State Cabinets / Brett Thomas

Steel Fabrication/Installation: Watkins Steel / Des Watkins