You’d miss it from the street. From Avenue de Saint Mandé in Paris’ 12th district, there isn’t even a hint of a new building. In the inner courtyard of a 1970s apartment block, however, a modest four-storey residential complex quietly takes pride of place, with a delicate structure of warm wood finishes emerging behind a rugged yet deftly manicured new urban landscape of boulders, ferns and evergreen trees.

Designed by local firm Mars Architectes, the 14-unit, 716-square-metre project was spurred by a recent change in Paris’ urban planning policy to encourage greater density on under-utilized sites. Situated atop a parking garage, the building had to be relatively lightweight and compact — necessitating spatially efficient low-rise massing to preserve natural light access for the surrounding apartment blocks.

Faced with a challenging set of constraints, the designers opted for a pre-fabricated timber-frame structure, utilizing a skeleton comprising of Cedar-based CLT and glulam, as well as modular Douglas Fir cladding. Since the site isn’t directly accessible by vehicle — let alone large trucks — construction materials were limited in size, and had to be delivered via the underground garage.

While the building’s pre-fabricated and seemingly dainty (though exceptionally structurally sound) timber design is partially a product of unconventional site conditions, Mars Architectes also opted to celebrate the structure’s lightness with an eye-catching exoskeleton of wrap-around balconies. Evoking the levels — and wooden joints — of a traditional Japanese temple, the simple and rigorously unified structure conveys a sense of tranquility that’s amplified by natural wood tones.

Stepping inside, the warm wood hues give way to a crisp white aesthetic. Past the small entry foyer’s subtle marble-pattern walls, a narrow inner courtyard offers a more private outdoor space for residents. Accented only by pockets of greenery, the radically pared down space — where the walls, furnishings and gravel are almost uniformly white — feels airy and breathable, belying its cloistered setting.

Like almost every facet of the project, the courtyard is also an exercise in spatial efficiency. Providing circulation for the building, the outdoor space allows almost the whole of the interior to be occupied by livable space, maximizing density. For each of the building’s 14 suites, the courtyard also facilitates pleasant dual-aspect exposure and natural ventilation.

Within each home, a simple yet eye-catching interplay of wood surfaces and crisp white walls defines the interiors. In the heart of a dense Parisian housing block, the organic simplicity of each apartment reinforces a feeling of openness and energy.

According to Mars Architectes, the project’s presence is inspired by the city’s surprising moments of delight. “Walking in Paris, we sometimes catch a glimpse of its hidden side, when a partially opened porch unveils an unexpected richness,” the designers explain. “A calm and peaceful atmosphere, precious and vegetal, which gives a particular relish to Parisian heart of blocks.”