FACING THE FUTURE OF FACADES: The facade that retains the sun

Architect Quico Jorreto achieves full comfort in this single-family house in Galicia in northern Spain by means of solar capture and insulation strategies, dispensing with heating installations.

The facades of a building form the protective casing that the act of inhabiting requires. And, at the same time, they constitute important surfaces of exchange between the interior spaces and the exterior. In this role, they have much to contribute in terms of sustainability. They also do this by means of the formulation of architectural solutions that work in favour of the environment at a time of climatic emergency.

That wisdom of traditional architecture that always sought the best orientation at midday, with the greatest number of hours of solar exposure, is now coming to the fore in order to achieve high levels of energy efficiency. This is one of the main strategies adopted by architect Quico Jorreto in the single-family house in Celanova, Galicia, with almost zero energy consumption. The project optimises sunlight in winter by having floor-to-ceiling windows facing south, which punctuate the single-storey building longitudinally. At the same time, to avoid overheating in summer, the sunlight is minimised by means of eaves and movable wooden shutters. In this way, the vertical slatted panels become a second skin that can be changed in terms of opening and closing.

The green roof, which acts as a fifth facade, has been landscaped and designed as a green extension of the plot, with the aim of further integrating the house into the territory. “The project on a conceptual level”, says Quico Jorreto, “could be defined as a small, friendly container of wood and glass, enveloped by another white, vegetal container embedded in the terrain, as if it were part of it”.

In the facade systems that will play a significant role in the evolution towards widespread sustainability, contributing to the future evolution of the climate, the facade itself takes on the role of a magnificent shelter. It is another of the fundamental strategies of the project that provides the maximum thermal insulation for the house through its perimeter walls, roof and floor with thick, high-density insulation. The large glass panels adopt triple-layer, low-emissivity technology.

“Within the airtight, super-insulated envelope”, specifies Jorreto, “is the living area, with the living room and kitchen on the south-east side, overlooking the villa and the plot. The rooms, also open to the south and to the interior of the plot, are designed as multi-purpose and transformable spaces.” The north facade, which faces the access road, is almost completely closed off. The architect has conceived the garage as an open multi-purpose space located in the western part of the plot, semi-buried and outside the energy envelope.

The result is a house of 110 m² useful space, inside the envelope, which does not require heating installations. This is a significant achievement as it is located in a climatic region in the north of Spain, where winter temperatures are harsh. Outside the minimum temperatures can reach 0º, while the interior remains at 19-20º. Likewise, the house has no cooling equipment in summer. And the architecture itself and its openings, plus the shading systems, favour good air conditioning. The house's electricity consumption has been minimised by reducing the number of appliances and lighting that are strictly necessary and are of maximum energy efficiency. “One of the most efficient architectural strategies in favour of sustainability is the elimination or minimisation of energy consumption in buildings”, Jorreto reminds us.

The project emphasises the airtightness of the envelope to avoid temperature losses. And it adopts a mechanical ventilation system with heat recovery and a Canadian well, which guarantees a healthy interior for its inhabitants. It is a passive house with almost zero energy consumption, certified by the Passive House Institute. With a heating energy demand of 10 kWh/(m²), it is the first of its kind to be certified in the province of Orense, in Galicia. For all these reasons, it has been awarded the GDA prize, created by the Galician Association of Architects to recognise outstanding work in the sector.

All images © Héctor Fernández Santos-Díez