Thorax House / Atelier RZLBD

Architects: Atelier RZLBD
Area: 1,800 ft²
Year: 2015
Photography: Borzu Talaie
Lead Architect: Reza Aliabadi
Structure: ADA Engineering
City: Toronto
Country: Canada

Thorax House, designed by Atelier RZLBD, is a minimalist two-storey residence located in the Lansing neighborhood of North York, Greater Toronto Area. The 1,800 ft² wood structure replaces a former bungalow and centers around a spine-like staircase and bridge that symmetrically divides the living spaces. The design takes inspiration from a thorax diagram, with the core circulation flanked by rooms on both sides. The exterior is modest, featuring grey stucco and black aluminum accents, while large windows and skylights provide ample natural light, meeting the client’s need for both illumination and privacy.

Situated on the southern edge of Lansing, Thorax House occupies the exact footprint of the one-and-a-half-storey bungalow it replaced. Atelier RZLBD’s design respects the simplicity of the original structure while introducing a modern, efficient layout tailored to the client’s needs. The house balances minimalist aesthetics with functional spatial organization, offering a contemporary interpretation of the modest bungalow that once stood on the site.

The design is based on a thorax diagram, featuring a two-part system on either side of a core. A central staircase and bridge (acting as the spine) run up the middle of the square volume, while living spaces (the lungs) are symmetrically arranged on both sides. The building structure and envelope can be viewed as the ribs, muscles, and skin. On the ground floor, the staircase separates the living room and gentleman’s banquette from the dining room and kitchen, while on the second floor it divides the master bedroom from the two guest bedrooms.

The dining area on the main floor is raised one step to align the kitchen island and dining table as a continuous surface. Despite the central division, carefully placed sight-lines allow views across the house, such as from the dining room to the stone slab above the fireplace in the living room. This unique marble was chosen by the client as a personal touch.

In the master bedroom on the second floor, the sleeping area is placed between the semi-open ensuite and walk-in closet, with views of the sky-lit living room through a double-height void. This void, illuminated by natural light, is also home to a 25-year-old plant that reaches into the space. The owner’s request for ample natural light and privacy is fulfilled by large rear-facing windows and three skylights: one over the bed in the master bedroom, one above the void, and one above the bridge. The skylights allow daylight to filter through, creating dynamic patterns throughout the day.

The exterior is rendered in grey stucco, maintaining a modest, monolithic appearance. Two lightweight black aluminum structures form the entry canopy and guard, with the only accent being a custom red signage designed specifically for the house.