With its dense jumble of middle- and working-class neighborhoods, mixed commerce, and scattered factories, the somewhat hilly municipality of Naucalpan, just northwest of Mexico City, is a nondescript extension of the vast metropolis. Devoid of notable landmarks or hip restaurants, it receives few foreign visitors. It’s a shame, because the area is home to a standout example of recent local architecture: Casa Gardenias, a house designed by 12-year-old boutique firm Vrtical for a design-loving mother-and-daughter duo.

Based in the booming capital, architects Luis Beltrán del Río and Andrew Sosa are the creative forces behind the smart, small- to medium-scale residential interventions that Vrtical specializes in. Their projects often incorporate existing structures, and in Naucalpan, too, elements of a residence that existed on site before were reutilized in the new design. “The preexisting house had no real architectural language or features worth preserving. Its value lay in reducing the need for new foundations and walls,” said Beltrán del Río. Accordingly, Casa Gardenias neither restores nor nods to what came before, instead simply recycling the structural parts deemed useful.

The brief was simple: to create an easily accessible studio for the daughter, a recent interior design graduate, that was connected to but also separate from living spaces the mother, a Chiapas-based small-business owner, could use when in town. Vrtical delivered exactly that, dressed in a captivating package. Viewed from the outside, on its prominent corner site, the hermetic beige massing of Casa Gardenias’s stacked cubic volumes contrasts effectively with a chocolate-hued gate in oxidized steel. The board-striated pigmented concrete used for all new additions gives the dwelling its singular character.

As is often the case in Mexican architecture, which has historically prized thoughtful sequencing over exterior spectacle, the generosity of Beltrán del Río and Sosa’s design reveals itself gradually behind the rusted metal gate. After you enter the house through the garage, a serene studio lies to the right, followed by a bedroom with an ample walk-in closet and adjacent bathroom. Crucially, the ground floor layout’s rear long side is left unbuilt, carving out a rectangular courtyard enclosed by a tall brick wall. In the mornings, light from this contained outdoor room permeates the studio, as does the dynamic, earthy effect created by the syncopated arrangement of the clay bricks. Aqua-green cement tiles cover interior floors and occasionally climb, mural-like, up walls, further livening the space, which is also activated with elegantly emphasized joints wherever distinct surfaces collide.

And yet, the downstairs serves merely as a restrained amuse-bouche for what comes next. From the main entrance, a somber staircase leads up to the primary apartment. The penumbra is deliberate, enhancing the wow effect as one first glimpses, nearing the top, Casa Gardenias’s luminous showpiece: a 420-square-foot salon that combines the living, dining, and kitchen areas. The space, at once compact and expansive, surprises with its enveloping warmth—all the more unexpected given the textural dominance, here as elsewhere in the house, of concrete—and skillful handling of light. Upstairs ceiling heights reach to 13 feet, magnifying the sensation of having entered a lofty, tranquil oasis. Juxtaposed with a coral-red cement tile floor, the kitchen’s oak fronts and raw, mocha-colored wall expanses, complemented by the clients’ spare furniture—including pieces in tzalam wood paired with a burnt-gold fabric—complete an alluring sea of harmonious tones and shapes.

Skylights, a Vrtical trademark, are deployed with rounded wall sections to modulate how incoming sunrays reflect on the brute concrete. “Even though the house looks inward, the outside had to brighten its spaces in a controlled way. So, we crafted an intentional dialogue between how the home is lived in and how light streams into it in the most precise, agreeable manner,” explained Sosa. This is evident at one end of the living room, where a narrow, glazed roof opening is slotted between a dual wall, directing the zenithal light down to a curved segment that juts into the room like a baseboard on steroids. The aesthetic gesture adds depth to the living area and, by concealing the illuminating source, a sense of mystery. But the voluptuous conceit is also dictated by Casa Gardenias’s contours, facing an abutting street, where an inclined public sidewalk runs under the house’s protruding second-floor volume. Regardless, the result is radiant, as a gentle glow bathes the convent-like nook at all hours (at night, from incandescent bulbs tucked inside the double wall).

Another bedroom suite, with its own bath and dressing room, completes the second-floor parti and, with it, the home’s modest program. Here, too, considered choices—such as a folding timber screen that can be unfurled to cover a big, square window—enhance the sensorial experience while redoubling the home’s defining aim: affording glimpses of the sky and exterior world while shielding intimate moments inside. The resulting tension is the most compelling trait of Casa Gardenias, a decidedly unostentatious house full of gratifying details that belie its introspective, slightly forbidding outward appearance. To the passerby, the mother-and-daughter domain suggests an impenetrability, a zealous protection of the private sphere. But once you are within, the skylights, high horizontal openings, and that oblong patio, with its lone old hule tree, ensure one never feels too removed from the surrounding city and the elements.