The public housing scheme in no. 8, Valle del Boi in the new district of Carabanchel is part of a wider policy being pursued by the Madrid City Council through its Empresa Municipal de la Vivienda y Suelo (EMVS). The plan to construct 59,000 houses by 2011 (32,500 of which will be built entirely with public funding) has set the scene for an urban model in which the outpost of urban growth is presented as an uninterrupted stretch of council dwellings for sale or rent – equitable to a carpet of homogeneous blocks at least six storeys high.

Looking at the Valle del Boi building in more detail, we should first point out that the scheme won a competition organised according to the public sector’s standard practices for commissioning projects. Secondly, it is the first major architectural project by a group of young architects who have taken the opportunity to establish a new kind of dia logue with the context, questioning the design of enclosed blocks (which are repeated obsessively in the dense grids of new building developments) and attempting to bring some order to the urban proliferation that is increasingly eroding the sierra.

While on one side the building allows views over the wood which lies beyond the main street, on the other it is set upon a base that opens onto the neighbourhood and takes the form of a garden facing the inner facade.

The architectural design is resolved in the relationship between the solid volume of the structural core, in reinforced concrete, and a system of additions with a lightweight metal structure. These lend a decisive sense of movement to the internal facade, as if it had been invaded by parasitic elements that have attacked the central core to establish a happy symbiosis, a possible allusion to life caught in the void of existence. This juxtaposition is also legible in the imperceptible surface treatment that modulates the light, letting it run across the smooth, warm concrete surface. The light is then caught up in the finely perforated sheet metal of the projecting elements, or filtered by a latticed grid orientated to intercept direct sunlight during summer and let through the weaker rays in winter. This grid design on the facade creates a changing perception of the main fronts – those in direct contact with the street. Thus when walking below it, the building suddenly comes into view against the light, revealing its body through the gaps in the grating.

The linear building is therefore conceived as an almost monolithic solid core, built entirely from concrete using an easily moveable modular system of aluminium formwork. The uninterrupted sequence of 102 units repeated along the building favours this system, which embraces an industrialised production model (a home a day) as an alternative to traditional construction systems, even though exploiting available means and consolidated practices.

Each house therefore consists of a fixed nucleus – also because of its material characteristics – which is repeated 102 times. The individual units, or “additions”, are fixed onto this spine and varied according to the request for different dwelling types set out in the EMVS brief (one-, two- and three-bedroom houses). While the fixed nucleus of each individual unit satisfies all the basic needs imposed by the brief – good orientation with respect to the sun, unobstructed views of the urban surroundings – the movement of the projecting masses gives a dynamic boost to the uniformity of the urban design.

The variation of housing type is achieved by programmatically adding the cantilevered units onto the main structure. As the architectural mass becomes confused with the decomposition of the projecting volumes and elements hanging from the central spine, the linear building’s rigorous order seems to contradict itself, creating a variable, unstable and inconstant impression.