At the age of 27, Álvaro Siza was proposed by António Jacobetty - the architect originally appointed by UNICOOP - to build the new headquarters of the Humanitarian Cooperative Society of All Classes of Consumption, Production and Construction.

The board of directors had bought a plot of land in Lordelo do Ouro, close to Avenida da Boavista and the vast Serralves gardens, on which Siza would explore an elevated layout, exploding the ground floor space from a right angle anchored by the entrance. This contrasted the three-storey parallelepiped volume of the administrative services with the fan-shaped articulation of the distribution services, a type of shop closer to contemporary supermarkets than to a traditional grocery shop.

The brutalist language of the exposed concrete was complemented by the warm expression of the afizelia woodwork on the façades, which blended in with the interior furnishings.

Unfortunately, six years after the 1963 inauguration, another administration replaced the wooden window frames with aluminium ones, on the recommendation of external technicians. The building has suffered greatly from this and other alterations, but despite some neglect, its structural vitality remains latent.