UNOBTRUSIVE CANOPY - THE SAN SEBASTIÁN PROTOTYPE

Description

The roofing of bar terraces in front of monumental façades raises problems of visual obstruction and urban landscape contamination. This case refers to the façade of the historic building "Hotel de Londres y de Inglaterra" at the sea front of Donostia-San Sebastián, Spain.
The design is based on a 4.70m x 4.70m self supported module composed by a horizontal steel frame hanged from two masts. The frame is completed by two low arches and braced by cable-ties. The roof itself is made of PVC coated polyester fabric resting on the arches and stretched against the frame by means of elastic rope.
The overall shape is perceived like a horizontal flat surface smoothly curved. It is stable because it's curved in two opposite directions, drains properly and arrives horizontally to the edges, avoiding vertical surfaces, pitched roofs, leaning planes or obstructive volumes.
The frame is formed by L shaped steel sections, so the perimeter is straight. It adapts to the straight line of the street and the building. It protects all the surface included by the structure - preventing the diminishments caused by the curved edges, simplifies the connection between modules and allows the installation of vertical transparent enclosures for winter time conditions.
The whole is supported by two masts, so the pavement is only affected in two points. Moreover, the distance between masts puts rhythm according to the repetition of the modules, independently of the different compositions of the buildings behind them and other elements of the street such as trees and lights.
The structure is lightweight and easily taken apart in order to be installed and dismantled each year, if necessary.
The result was satisfactory enough to use the "San Sebastián" canopy in other locations for other purposes.

Description of the environmental conditions

General comments, links

www.upc.edu/ca1/cat/recerca/tensilestruc/portada.html