Desert City Project
San Sebastián de los Reyes, Madrid
Year of construction
Name of the client/building owner
Desert City LTd
Function of building
Degree of enclosure
Fully enclosed structure
Mediterranean - mild winters, dry hot summers
Number of layers
Type of application of the membrane
Desert City LTd, the Spanish pioneer xeriscaping company, entrusted to García-Germán Architects Studio the design of their
Headquarters in San Sebastián de los Reyes. The building is composed by volumes connected by means of peripheral walkways, freeing the in-between space existing after having built such volumes and generating a first cactus open-air showroom. The main volume has got an inner courtyard, intended to be the principal cactus exhibition and wished to be covered by a light and permeable roof. The dimensions of this courtyard are 37m x 42m which gives a surface of 1.575m2. What better solution than an ETFE foil roof to provide a perfect showroom inside a bubbling greenhouse? So, this was the seed of the covering design.
The Desert City Bubble Roof structure is arranged in three levels, the main steel frame, composed by four longitudinal sloped beams fixed to a peripheral pipe steel shaped frame; a second level, composed by the tensegrity transversal girders and the ETFE cushions as the third level.
Two layers cushions were used with transparent sheet in the top layer and a white translucent sheet in the bottom layer. Both layers have got a thickness of 250microns, with a ratio of sag vs length of 1/10, usual value for ETFE cushions, providing a good balance between shape and tension to be resisted under external loading.
Previously to the adoption of the layer colors, mockups were developed in the Lastra&Zorrilla Workshop, the ETFE Manufacturer, and delivered to site in order to check the transparency desired to be provided inside the cactus exhibition courtyard, checking directly with the light present in Madrid.
Description of the environmental conditions
General comments, links
Prizes: XIV BEAU Bienal Española de Arquitectura y Urbanismo 2018 Prize, Fuera de Serie Prize 2017, Finalist FAD Prize 2018
Material of the cover
Main dimensions and form
Covered surface (m2)
Total length (m)
Total width (m)
Duration of use
Temporary or permanent structure