- Design Team : Palma Pajarón, Néstor Cruz, María Martínez
- Clients : Autoridad Portuaria de Motril
- Engineering : Juan Fernández Cañedo
- Collaborators : Francisco Campos Fernández, Director de Obra
- City : El Varadero
- Country : Spain
Text description provided by the architects. In 2017, the Port Authorities of Motril announced a contest for the new Headquarters of Port Operations of the National Police in order to control the activities carried out in the harbour. The proposed location between fishing vessels a few meters from the Mediterranean is strategic as a control point. This position together with the proximity of groundwater makes the design a sum of architectural and energy-related decisions with the goal of achieving a building with zero energy consumption. Formally, a strategy of sealing the corners and opening the interior spaces is chosen, with a system of courtyards that act as thermal regulators and contribute to the light quality and permeability of the interior.
The exterior and interior images of the building are strongly characterized by the bareness of their materials, which have the raison d'être in their constructive and energetic capacities. On the exterior, large glazed cloths with panels of blinds are installed between clean stone-like volumes. On the interior, the white brick walls and concrete ceilings and floors are materials of great inertia, active characters of the building's climate, and transmit energy progressively to the interior.
All these constructive decisions of the building are closely related to its NZB energy concept (Near Zero Building), the goal of zero energy consumption. The energy approach designed for the building is based on the premise of maximum efficiency in energy production and recovery systems with renewable energy input. The geothermal system takes advantage of the existence of groundwater accessible in the subsoil, ensuring a highly efficient air conditioning system and DHW production using a geothermal pump. The projected roof surface for covered car parks is utilized for photovoltaic solar collection, with the installation of a photovoltaic solar field integrated into the architectural design.
All of this is supported by the general process of an active envelope. An inertia system designed with the concept of hypogeal architecture as a starting point, where the exchange of energy between the interior environment of the building and the subsoil is facilitated, while it is isolated from the exterior environment. A double envelope construction system is designed, both in vertical and horizontal elements, capable of storing the air conditioning energy and creating a circuit that transmits it progressively to the interior environment, taking advantage of the thermal inertia of the materials.
The exchange is produced by inertia, so that the thermal jump between the air-conditioned environment and the air-conditioning fluid (air in the double envelope) is diminished, achieving a highly performing installation. Very little energy is needed to temper the recirculating air. With this active envelope system, a disconnection on energy-level takes place between the interior environment and the exterior, and a “cave building” is achieved.