Contracting authority: Insurance Compensation Consortium.

The refurbishment of the Paseo de la Castellana 14 building consists of the complete demolition of the previous building, maintaining the two main façades, and constructing a new building from 4 floors below ground level to 6 floors above ground level. A new building for the Audiencia Nacional (National High Court), Social Administrative Disputes Chamber.

The building dates back to the end of the 19th century. It has protected elements such as the entire exterior façade, the leading entrance portal and the internal staircase. This feature gives the project a particular uniqueness, as in addition to refurbishing these elements, the structure is intended to be transformed into a modern building that increases the space available for office use by reducing common areas, lobbies, etc. To this end, Sando incorporates innovative technologies and construction systems that allow the introduction of improvements in energy efficiency to obtain the highest rating in demanding certifications: LEED Gold certification, which accredits reaching high standards in terms of energy efficiency of the building.

The refurbishment of the Paseo de la Castellana building consists of 4 new basements, a ground floor, six other floors and a roof. An excavation of 15.5 metres will be carried out to construct the four parking levels The floor slabs are made of exposed solid slabs of active concrete (i.e. air-conditioned through hot and cold water circuits, depending on whether it is winter or summer). The office partitions are made of glass partitions towards a longitudinal corridor to make the most of natural light and wooden board partitions between offices. The floor slabs are made of exposed solid slabs of active concrete.

As energy support, a geothermal system is being installed for air conditioning, with 12 wells with a depth of 100 metres, and a photovoltaic system for electricity.

In addition, unique elements such as constructing a new concrete spiral staircase, reconstructing a marble staircase, and having a large skylight are included. Carpentry work is being carried out on the main façade, windows, and wooden friezes to rebuild them with solid wood, maintaining the aesthetics of the building.

For its execution, Sando Construcción implemented a construction solution called Prorehesla. A methodology that allows the massive collection of data for the execution of works using BIM (Building Information Modelling) technology.