Mexican studio Espacio 18 Arquitectura has balanced an expansive concrete house designed like a "rock carved to create a sculpture" on a hillside in Oaxaca.

Known as Casa del Alma, the 460-square metre (4,950-square foot) house was completed in 2023 as the client's "last refuge" after a "long life of work and travel", according to Espacio 18.

Two concrete boxes – set in the highest up next to an ecological reserve – frame views of Oaxaca City and create a space for "peace, meeting, contemplation, and introspection", Espacio 18 said.

Structural concrete embeds the house in the terrain and the boxy concrete forms jut out in cantilevers from the slight slope.

"This project was inspired by the masters of light, such as [Gian Lorenzo] Bernini or current masters such as Alberto Campo Baeza," the studio said.

"The different uses of light in the space allow the project to evolve during the day, during the year in the different seasons. It's as if it were a rock carved to create a sculpture."

The two halves are divided by a monumental, entry staircase with floating concrete treads and light that filters down between the concrete beams.

"Through vertical subtractions, we work with light, creating domes, beams and windows," the studio continued. "The light expands through the spaces, bathes the walls and shows us the passage of time."

Set primarily within a single level for the convenience of the resident – despite the entry stair – the program is separated into public and private zones on either side of the staircase.

One side – which is slanted deeper into the hillside – holds service areas and the kitchen, dining and living spaces, while the other holds two ensuite bedrooms.

The interior finishes are minimal, leveraging the poured-in-place concrete structure and polished concrete floors with exposed aggregate. Low-profile glass and metal serve as additional detailing.

Large rectilinear skylights illuminate the bathrooms and the circulation spaces, where the repetitive concrete beams reappear.

The spaces that face away from the hill are characterized by floor-to-ceiling glass sliding doors that allow the view to serve as the fourth wall.

The linear balconies have no roof but are wrapped by a deep concrete beam as well as delicate glass railings.

The staircase wraps up to another bedroom and an expansive terrace that looks out to the surrounding landscape and city. An outdoor kitchen is built into the rooftop.

In the basement, the parking area and mechanical rooms are tucked under the concrete cantilever.

The layout allows cross ventilation both horizontally and vertically to mitigate the warm climate of Oaxaca, and a rainwater harvesting system and LED lighting contribute to the home's resiliency.

Espacio 18 Arquitectura also completed a concrete and terracotta beach house in Oaxaca that orients to the sunrise and sunset, as well as a dark grey townhouse with a glazed interior courtyard in Puebla.

The photography is by César Béjar.

Project credits:

Design: Espacio 18 Arquitectura
Interior design: Espacio 18 Arquitectura
Builders: Espacio 18 Arquitectura
Architect in charge: Sonia Morales
Landscaping: Espacio 18 Arquitectura
Team: Mario Ávila, Carla Osorio, Sonia Morales, Karina Flores, Paola Alavez, Marco Farias, Noemié Coquil
Carpentry: Orvesa y diseño
Engineer: LM Estructuras
Steelwork: Alfredo y Ramon
Interceramic: Bathroom Furniture and hardware
CEMEX: Concrete
GEO Iluminacion: Lighting project
Concrete workshop: Terrazo