There are places that stay with you long after you leave and Casa Plaj is one of them. Set in the quiet landscape of Lourinhã it feels more like a retreat designed with intention than a simple holiday rental. Everything about it invites you to slow down notice the details and fall into the rhythm of the surroundings.
The house’s form is reductive, almost elemental. The architects shaped a radically simple volume inspired by traditional local buildings but rendered with a contemporary sensibility. Inside the 120 square metres, the central living, dining, and kitchen area flows openly. Bedrooms face south. Terraces on all sides, floating above ground, blur the boundaries between inside and out.
Geometry at Play
Look at Casa Plaj from above and you’ll be met with the wonders of geometry. Rectangles, squares, perfect circles, and ovals, it would seem as if if the building was drawn with a compass and set square before anything else.
At first glance, the house reads as pure form, with elemental shapes arranged with surgical precision across the sloping terrain. But the geometry isn’t arbitrary. A series of circular skylights, designed precisely within the structure using a 3D model, allow light from the main skylight to cut through the house, reaching spaces that would otherwise sit in shadow.
For four months each year, beams of light illuminate individual rooms before sunset, peaking at the summer and winter solstices. The circles aren’t decoration. They’re light cones, calculated and placed to work with the sun’s arc, transforming geometry into a functional choreography of daylight and volume.
The Relationship with Light
Inside Casa Plaj, light becomes texture. The east-facing guest bedroom receives morning sun only briefly, so a series of oculi was designed to filter light through the living room and bathroom. The kitchen, Anna’s favorite room, is built around light from three directions. Every window is pocketed, sliding fully into the walls so there are no traces of glass anymore. From above, a high rear window filters daylight in, drawing the eye to the full ten-meter volume of the space. The effect is total immersion. No frames, no boundaries, just air and brightness pouring through.
Then there’s the red glass in the pool. A window was added midway through construction, then fitted with coloured glass that casts a warm, altered view of the outside world. “You’ve never seen the exterior world through red,” says Caldeira Ferrão. Even in winter, when the Atlantic coast turns cold and grey, that red-filtered light brings warmth. It’s a visual trick that keeps the space feeling alive regardless of season. It’s a small intervention, but it changes everything. Light becomes colour, colour becomes atmosphere, and suddenly the house isn’t just lit, it glows.
Casa Plaj is a reminder that thoughtful design can change how we experience a place. Light geometry and atmosphere come together to create something calm and quietly striking. It is the kind of space that makes you want to return before you have even left.
Images © Clemens Poloczek
