Open competition called by Barcelona City Council for the execution of the executive project and construction management for the remodeling and expansion of the Sagrera Tower. Proposal.

We proposed a room completely free of the existing building. This room opens onto a large English courtyard from which it will receive indirect natural lighting and ventilation. Its semi-buried position guarantees maximum levels of sound insulation and optimum acoustic conditioning, thanks to a considerable proportion and ceiling height (4.5-5 m). Being buried, the external height of the room does not exceed that of the perimeter protection. A small passageway is created between the hall and the existing building, allowing ramp access in cases where independent access to the hall is necessary.

The support system of the multifunctional hall is made of concrete walls throughout the semi-buried part, while a timber frame system is erected on the ground, on walls and roof. This construction, intended to be as light as possible, combines a high level of thermal insulation with good acoustic performance. The low inertia is optimal for discontinuous use and air conditioning. The wood acoustically provides a good natural behavior that minimizes overlapping corrective complements and provides a clean and spacious space.

The roof of this room, visible from the existing building and from the new surrounding buildings, is landscaped with xerophytic vegetation, with a variety of colors and low water consumption. The landscaped finish helps to highlight the existing building and does not represent an irrigation burden, thanks to its own configuration with xerophytic vegetation.

The maximum number of uses of the program are located inside the existing building, foreseeing an integral rehabilitation to reinforce the existing ceilings, condition the spaces, incorporate new services and add all the necessary complementary equipment. The new program is arranged respecting the organization of the existing floor plan. The layout of the scale, which will be the main route between the three main floors, is completely preserved, distributing the rooms on both sides, highlighting the original symmetry axis of the building.

The heights of the future building planned for the southern boundary of the site (PB+6 in height) will represent a shading over the room that makes any direct solar collection system (whether thermal or photovoltaic) unfeasible. A geothermal heat pump thermal energy production system is proposed as an alternative for its efficiency. It will allow both the production of cold and heat and generate DHW. This highly efficient and compact system also allows to free the roof and the space under the roof, from the servitude of the exchangers of the air-air heat pump systems.