Ortega Diago Renovates 19th-Century San Sebastián Apartment with Light as Central Element

The architectural firm Ortega Diago has completed a renovation of a 170-square-meter residence located on the top floor of a historic 19th-century building in San Sebastián, Spain. The project distinguishes itself by making natural light the fundamental organizing principle, rather than treating it as a secondary consideration. The design utilizes the apartment's height and orientation to transform daylight into the primary element that shapes spatial organization, material selection, and atmospheric quality. The architects deliberately avoided reconstructing historical elements, instead focusing the intervention entirely on the interior experience. They describe the residence as a sequence of spaces where illumination defines the ambiance, with the design prioritizing the inhabitant's sensory journey. A key architectural gesture involves reimagining the corridor from a typically marginal passage into an active, widened component that functions as a central spine, connecting various domestic zones and creating graduated levels of privacy. Glass block screens are strategically placed to filter light between rooms, softening boundaries and maintaining visual continuity while enabling gradual transitions. Material choices follow a restrained, nearly monochromatic palette centered on sandblasted Campaspero stone, used for both flooring and wall surfaces to create continuous planes. This stone was selected for its capacity to absorb and subtly reflect changing light throughout the day, particularly during evening hours when the space acquires a more intimate character. The interior design reinforces this calm aesthetic, blending classic pieces like Fritz Hansen's Ant chairs and Vitra's Akari lamp with contemporary designs, including the studio's own Tarugo chair. Photography for the project was handled by David Zarzoso and Mari Luz Vidal. The work represents an architectural approach that constructs atmosphere experientially rather than focusing solely on formal composition.