The curtain wall: either a finishing or a support (046)
The stick curtain wall, consisting on a simple mullions and transoms structure and glass, has always allowed hybrid solutions. There are several examples where the curtain wall gives just the image of the building, covering an interior enclosure normally of heavy and wet construction. This solution is usually the result of the will of giving an image of glass skin in spite of its shortcomings: either this enclosure is not enough to solve functions such as acoustics or thermal, or either the inner space needs perimetral walls. This is how representative buildings such as the two towers for La Caixa by J.A. Coderch and J Marti were built in 1978.
The evolution of the curtain wall systems and the glass industry, could suggest that these solutions belong to the past but nothing is further. Buildings such as the Police Headquarters of the Mossos d'Escuada at les Corts neighbourhood in Barcelona or the dwellings towers of Alonso and Balaguer in Europa Square, resort to solutions where the curtain wall covers a heavy interior wall. The reasons are different in each case (see study cases) but the final solution is always a false image of transparency and lightness.
Curiously, this stick curtain wall that, in many occasions, seems needing to be completed with a heavy interior wall is, in other occasions, used as the inner sheet of another outer covering.
Historical facades such as Carburos Metálicos at Aragón Street in Barcelona or singular experiences such as those from Mecanofas (see study cases) illustrate this other way of proceeding. On those examples, we do trust in the benefits that the curtain wall, closed with different kind of panels, can provide. The curtain wall is used precisely to build the main facade layer, that is, the support element and airtight limit, fleeing from wet and heavy techniques. The curtain wall is hidden, covered both from the inside and the outside.
If in the first examples the curtain wall is used due to its technological image and the lightness it brings; in the seconds, we seek for the performances that those same characteristics can bring.