Portuguese architecture firm Traçado Regulador, dedicated to the development of projects and consulting in architecture and engineering, has designed a single-storey house in Viseu, which hinges on the trait that it can be used as a single house or as two autonomous dwellings. Designed as a single storey building and set on a plot with 3,700 sqm, with 525 sqm of gross construction area, the house stands out for its glazed floor to ceiling openings, which enable a powerful relationship with the outside, from the inside. A contemporary language, with a careful interplay of transparency, solids and voids, light and shadow, gives substance to a vast functional programme with generous areas. With an A+ rating, the new project is equipped with off-grid photovoltaic energy production and energy systems designed for rational energy management. All rainwater and drainage water from the ground around the building is channelled to a tank and used for watering the garden. Located in the municipality of Mangualde, the house blends into its surroundings, with the bonus of having a breath-taking view over the surrounding natural landscape.