Stairs Canyon: Multigenerational Housing Carved from Lima's Coastal Identity

What if the staircase were the most important room in the house? In Stairs Canyon, the act of moving between floors becomes the primary social ritual: a vertical promenade modeled on hiking through a rocky gorge, where residents pause, talk, and take in shifting light. The project refuses to treat circulation as leftover space, instead positioning it as the connective tissue that holds a multigenerational household together.

Designed by Milena Sommer and published on uni.xyz, Stairs Canyon is a residential concept for a family of six in Lima, Peru: parents, two children, and grandparents. Sommer draws on Lima's rocky Pacific coastline and traditional adobe construction to produce a monolithic dwelling of stacked, warm-toned volumes that sits comfortably within the city's material palette while responding directly to the arid coastal climate shaped by the Humboldt Current.

Stacked Volumes, Planted Terraces

The rendered exterior reveals the project's defining move: offset volumes that terrace upward, each topped with planted rooftop gardens of climate-adapted species. A perforated disc canopy hovers over the entry, filtering light into a dappled pattern that recalls shade beneath desert vegetation. The massing reads as a single carved landform rather than a collection of rooms, a quality reinforced by the continuous warm plaster finish. By rotating and shifting each block, Sommer ensures that wall surfaces face outward, granting every room exterior views and cross-ventilation without relying on windows that look into neighboring properties.

The Outdoor Staircase as Social Space

Step inside and the staircase dominates. Bright sunlight pours through openings cut into thick textured plaster walls, turning each landing into a moment of orientation and encounter. The section drawing beside it confirms the spatial logic: multiple levels connected by internal and external staircases, with a tree growing alongside the building to anchor the composition in greenery. This vertical journey is deliberate. Older residents receive the rooms with the least stair access, while shared zones like the kitchen, living areas, bathrooms, and terraces sit at levels designed to draw all three generations into contact.

Lima's arid climate, with its mild year-round temperatures, makes an external staircase not just poetic but practical. Residents can use these outdoor passages every day, and the canyon-like proportions between walls create natural shade and channel breezes upward through the building.

Intersecting Geometries Seen from Above

The top-down view makes the plan strategy legible. Staircases and volumes interlock like puzzle pieces, carving out narrow voids that admit light deep into the interior. The warm textured plaster reads as continuous, reinforcing the monolithic quality Sommer is after. What could feel claustrophobic in plan instead feels porous: every room has a path to daylight and air, and the residual spaces between blocks become micro-terraces and planting pockets rather than dead zones.

Private Rooms Framed by Desert Landscape

The interior rendering of a private room captures how the building balances intimacy with openness. A tall, narrow window frames a single cactus, composing a view that is almost painterly. Floor plan drawings at right confirm the room's compact footprint and its relationship to adjacent circulation. Materials remain deliberately restrained: stabilized adobe and clay plaster sourced locally, consistent with Sommer's commitment to minimizing material variety, reducing waste, and supporting Lima's local construction economy. Prefabricated components assembled on site keep costs down and construction timelines short.

Why This Project Matters

Stairs Canyon is a serious argument for rethinking how urban housing in rapidly growing cities can accommodate extended families without defaulting to sprawl or high-rise anonymity. By concentrating social life in the staircase and distributing private rooms across offset volumes, Sommer creates a dwelling that is dense yet breathable, communal yet private. The approach to climate, with its passive ventilation, terraced massing, and year-round outdoor living, demonstrates that sustainability and spatial generosity are not competing goals.

Equally important is the cultural anchoring. Rather than importing a universal housing typology, the project grows from Lima's own geology and building traditions: the rocky coastline, the adobe vernacular, the warm earthen palette. For a young designer, this is a remarkably confident synthesis of context, program, and construction logic, and it points toward a model of multigenerational urban living that other coastal arid cities could learn from.

View the Full Project

About the Designers

Designer: Milena Sommer

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Project credits: Stairs Canyon by Milena Sommer.