Each room of this townhouse in Spain is a separate block with a translucent frontage, which together create a stepped facade that glows after dark (+ slideshow).

Local firm Rue Space slotted the house into a six-metre-wide gap between the party walls of two existing structures in Cintruénigo, a town in the wine-making region of Navarra.

Named Casa #20, the new home incorporates some of the remnants of an ancient house that once stood on the site, including its stone well.

Each of the blocks that make up the building is fronted with U-glass – a translucent glass that is installed in narrow vertical panes. The blocks are arranged around a white staircase that rises up through the centre of the plan.

Alternating between street- and garden-facing facades, the rooms are all set at different heights. The glazed walls ensure each room is filled with as much daylight as possible.

Outdoor terraces are formed behind the parapet walls, while a small yard separates the house from a guest annex with a rooftop swimming pool.

"The stepping facade and the yard allows the entrance of sunlight during most of the day, generating different terraces alongside each room," explained the architects. "The oblique alignment of these terraces helps to solve the irregular shape of the plot."

Two reinforced concrete frames inserted between the neighbouring structures bear the weight of the buildings' concrete floor slabs.

Inside, a layer of microcement applied over the slab forms a smooth flooring for each level, while the underside of the concrete was left exposed to give an unfinished appearance to the ceilings. The walls are covered in a combination of white ridged brick and painted plasterboard.

The main entrance is set behind a wide garage door made from perforated stainless steel. A doorway at the back of the garage opens into a bright white kitchen.

Glazed doors provide access to the small patio to the rear of the building and guest annex beyond. A white spiral staircase leads to the rooftop pool, which is shielded from onlookers by two tall white-tiled walls.

Inside the main house, the staircase leads down into a basement lounge and utility room brightened by a lightwell, and up to a second sitting room and three bedrooms arranged on alternate sides of the stair.

"The stairs assume the function of a vertical corridor, with no need for landings or hallways," explained the architects. "The rooms are disposed according to a privacy gradient."

Mottled brown doors provide privacy to bathrooms that are located around the open stairwell, while bedrooms only separated from the floor plan by translucent walls are granted privacy by soft white curtains.

The three bedrooms have wedge-shaped terraces, while a large glass-fronted terrace occupies the uppermost level.

Photography is by Aitor Estévez.

Project credits:

Rue Space: Raul Montero, Emilio Pardo
Budget architect: Pedro Legarreta
Collaborator: Laura Montero
Structure calculation: GB Ingeniería
Installations design: L'Sol