The curtain wall: either a finishing or a support (046)


The curtain wall: either a finishing or a support (046)

The stick curtain wall, consisting of a simple mullion and transom structure and glass, has always allowed for hybrid solutions. There are several examples in which the curtain wall gives just the image of the building, covering an interior enclosure that is normally of masonry. This solution is usually the result of the desire to give an image of a glass skin in spite of its shortcomings: either this enclosure is not enough to resolve functions such as acoustic or thermal insulation, or the inner space needs outer 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 curtain wall systems and the glass industry could suggest that these solutions belong to the past, but nothing is further from the truth. Buildings such as the Police Headquarters of the Mossos d'Esquadra in the Les Corts neighbourhood of Barcelona and the residential blocks of Alonso and Balaguer in Plaça d’Europa use solutions in which the curtain wall covers a heavy interior wall. The reasons are different in each case (see case studies) but the final solution is always a false image of transparency and lightness.

Stick curtain wall
Stick curtain wall

Cladding over a stick curtain wall support

Stick curtain wall cladding a wall

Curiously, this stick curtain wall, which often seems to need to be completed with a heavy interior wall, is on other occasions used as the inner sheet of an outer covering.
Historical facades such as Carburos Metálicos in Carrer Aragó in Barcelona or outstanding examples such as those of Mecanofas (see case studies) illustrate this alternative solution. These examples take advantage of the benefits that the curtain wall, closed with different kinds of panels, can provide. The curtain wall is used precisely to build the main facade layer, that is, the support element and airtight limit, thus avoiding the use of masonry. The curtain wall is hidden, covered from both 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 second it is used for the performance provided by these characteristics.