Via Studio Banana Tv
Studio Banana TV interviews Belzunce-Mauriño-García Millán, authors of the hill-crawling social housing complex in Mina del Morro, Bilbao.
The initial needs program, proposed for the Europan 4 competition, called for the construction of 356 dwellings on a plot of land of 29,500 m2. These housing units were complemented by 8,700 m2 for commercial use, 16,100 m2 for services, and 4,400 m2 for social infrastructures. Of course, solutions were also needed for the street network and parking areas, as well as providing the lot with green areas and outdoor public areas.
“The plot was situated on the edge of the neighborhood of Sagarminaga —a heterogeneous collection of apartment buildings for the lower income classes—, erected in the fifties and sixties with a high building density and low urban quality. The land was steeply sloped and had previously been occupied by a mining operation, now in disuse, which had dug numerous tunnels in the subsoil. From the very start we were interested by the frontier nature of the place, a no man’s land between the old city center and the outskirts, between the Nervión river and the surrounding hills, between nature and the city… The project explored this ambiguous status. Therefore, one of the operations investigated in the project was to manipulate building density in order to address the different conditions that were to emerge after the initial indeterminacy of the site, whose mixed nature it was always attempted to preserve.
To solve the needs of the near, we proposed a rather introverted neighborhood cluster, low in height and surrounded by a higher level perimeter concentrating the commercial and service areas and infrastructures, which would be closely linked to the neighborhood. The existing densely built-up neighborhood was thinned out by preserving for public use two large open spaces, well sunlit and offering distant views, and the free spaces between the towers were conceived as urban viewpoints. In the heart of the cluster, the buildings rise over a tapestry of green areas, the street network is resolved by an inner ring road, while the parking lots are concentrated in the perimetral buildings.
In addition to treasuring this potential-laden indeterminacy, the site could become a urban façade toward the entrance from the Bilbao highway. To respond to the requirements of the far, we proposed a new image for the area by means of a line of several towers which would act as a visual filter of urban environment lying behind them, introducing the qualities of order and repetition.
After modifying the proposal as a result of winning the competition, we were commissioned the construction of one of the resulting lots, lot number 4. The remaining lots were commissioned to other architects, obviously with uneven results.
This lot is one of the two making up the central area of the complex. It is composed of six dwelling units that are strewn on the slope with river basin randomness, unsubordinated to parallel alignments but controlled by a rational geometry. Developing the design concept of “elongated-staggered-broken”, the layout of the blocks leaves pulsating exterior openings that widen or narrow to produce an intermediate scale of common spaces.
The blocks have a mixed typology between the volume of single-family row houses and the functioning of a public housing building with entrances through a corridor. Each dwelling is entered from the exterior, with the independence of the individual, but they piled one on top of the other, with the logic of the collective. The orientation of the buildings necessarily implied that the entrance passageways, onto which open the entrance halls, kitchens, drying areas and bathrooms, were placed on the northern side of the buildings, while on the southern side, open to the sunlight and views, the bedrooms and living rooms were located.
The floors are organized by a succession of bands of different uses and characteristics: exterior entrance passageway, utility duct, bay for service rooms and bay for other rooms. The sections are established as a stacking of habitable strata separated by continuous floor slabs. The broken staggered geometry of the buildings causes a displacement of the dwellings within the horizontal strata, such that there is vertical continuity of the different functional bands but not of the dwellings, which slide horizontally one over the other.
The construction is quite simple. The horizontal sliding of the dwellings determined that the structure had to function as a system of parallel planes, the only geometric element that ensured continuity. As a result, brick load-bearing walls were used, supported by one-way concrete joist floor slabs. The low height of the central blocks implied a small transmission of loads to the ground, whose delivery was resolved by continuous superficial foundations. However, a very conservative geotechnical survey required the use of piles driven to a depth calculated only at the tip to avoid the stratum hollowed out by the mining tunnels. Thus, the blocks, as if they were “caterpillars”, ended up growing abundant very long feet until reaching the bedrock below —which were micropiles up to 30 meters in depth and only 16 cm in diameter—. Sometimes we would like the ground to be transparent…
Interview by Studio Banana TV. Translation by Remy Arroyo.”