The building, with a ground floor and six stories, caps one of the built-up strips that enter the interior of the park of the former Sant Andreu barracks (seaside side). Located at a higher level than the main pedestrian circulation axes of the park, the building occupies a privileged visibility zone from the public space, especially due to its east-facing façade. The ground floor is surrounded by pedestrian circulation routes that connect the lower level of the park to the upper level via two stairways, thus creating a strong circulation node. The façades of the adjacent buildings present a rather hermetic architecture in line with the urban planning regulations of the area, with flat façades and vertical windows as the only elements linking the interior of the homes to their surroundings.
The façades of the proposed building provide a dual response: on one hand, they project the structural system to the exterior, creating a façade of Cartesian geometries that attach to and extend the compositional lines of the adjacent housing block; and on the other hand, the community life of the cooperative project is exposed to the park, facilitating the dual view —from the building to the city and from the city to the building— as a fundamental principle of a well-maintained and safe public space, while also promoting the cooperative housing management model.
The collective spaces are located at height, giving maximum collective activity to the east-facing façade of the building, from the ground floor to the roof. This reduces internal pathways between the apartments and these spaces (each floor has a portion of collective space) and promotes ground-floor housing for both accessibility reasons and direct relation with the public space.
Four strategies, one system
The main value of the proposal lies in the transversal idea of efficiency, integrating four strategies into a single response. The building is conceived through two differentiated yet complementary collaborating systems:
Economy
The total buildability is dissociated into two qualities of performance: one with high thermal, hygrothermal, acoustic, and health performance, where the 35 housing units will be located, and another with more limited performance, housing the collective spaces, accesses, and semi-exterior galleries. In addition, the material resources that make up the building are reduced. On one hand, the structure is optimized by dissociating its loads, reducing its own weight and optimizing the spans of the floors according to the optimal criteria for each material; on the other hand, with high energy efficiency that allows us to do away with heating and cooling systems.
Flexibility
The structural system of the housing units consists of load-bearing walls that create a grid of multifunctional rooms, four meters wide by three and a half meters deep, connected to the north and south galleries. Access to the housing is through the collective spaces and galleries, forming a privacy gradient (from more public to more private) along the route.
Energy, environmental impact and health
We propose a building with low environmental impact and a positive energy balance.
The system of galleries and community spaces (B) functions as a first bioclimatic skin that acts as a thermal buffer in winter and as an exterior solar protector in summer, providing the housing with 62.79% of the hours of passive comfort throughout the year. It also pre-treats the clean air that enters the home naturally, which is extracted through the central screens to the roof with a hybrid ventilation system. To ensure air quality in the galleries, relative humidity and CO2 sensors are planned, linked to mechanized openings located in the façade. The flooring of these spaces provides the necessary thermal inertia to extend comfort hours.
The interior walls of the housing (A) are made of compacted earth blocks (BTC), which contribute 17.49% of the annual passive comfort hours, in addition to the significant reduction in environmental impact that comes with using a material with these characteristics. In addition to thermal inertia, the BTC provides significant hygrothermal control of the indoor air, which is closely tied to the comfort of the housing and the health of its occupants. This construction solution significantly reduces the environmental impact of the building’s construction.
The remaining 19.73% of the time we will be in passive discomfort, reaching a minimum temperature of 15ºC on some nights of the year. Both for economic viability and environmental impact, the building will not have a heating system, considering the option of having a punctual auxiliary support (Joule effect) for those units that desire it.
