Under an ETFE sky
Stride Treglown Architects
In the early nineteenth century, town planners in Paris created a maze of passageways called “passages couverts”, which ran from one building to another under elegant glass roofs. Celebrated by German philosopher Walter Benjamin in his analysis of the figure of the “flâneur”, there were more than 150 of these covered arcades in the capital and dozens elsewhere in Europe. Following a period of relative neglect, the introduction of innovative technologies has recently sparked renewed interest in large glass domes. Two of the most spectacular examples are the futuristic Eden Project by Nicholas Grimshaw in Cornwall and the splendid Great Court at the British Museum in London, designed by Norman Foster. These works, which are both located in the UK, are mentioned as they have some features common to the project we look at in this article. The first shares with our project the translucent covering of inflated ETFE (ethylene tetrafluoroethylene) cells, the second the solution of renovating an existing internal courtyard for use as a high-quality public space.
In this project, Wiltshire County Hall – located in the county town of Trowbridge, about twenty kilometres from the historic city of Bath – underwent radical regeneration, expansion and energy optimisation work assigned to the practice Stride Treglown Architects. The original buildings consisted of a 1930s civic building and a seventies volume requiring maintenance. Along with spatial reorganisation, the project also involved the construction of a new three-floor building connecting the existing volumes and completion of the courtyard perimeter. This new unit accommodates the main entrance, the stairs and lifts, and a series of meeting rooms. The new centrepiece of the complex is the courtyard, a previously underutilised space now transformed into a bright, vibrant public services hub. Entirely covered by a lightweight roofing system consisting of transparent ETFE cells anchored to guyed tubular steel trusses, it houses the main reception, info points, exhibition areas, waiting areas with seating and a bar. These facilities complement the services distributed throughout the buildings, including a new public library, dining area, registry services and meeting rooms.
Much attention has been devoted to the quality of the materials and finishes in terms of both shape and colour, as well as durability and environmental characteristics. An important design feature was the decision to cover the entire courtyard floor and library entrance area with porcelain tiles produced by Ceramiche Refin. In particular, the design team opted for the Zinc colour from the Visual collection in a 60×60 cm size, installed in a linear pattern in keeping with the architectural choices made for the entire building.
Refin, Visual series
Water absorpion (ISO 10545-3): 0.2%
Chemical resistance (ISO 10545-13): compliant
Resistance to deep abrasion (ISO 10545-6): ≤ 175 mm3
Stain resistance (ISO 10545-14): compliant
Frost resistance (ISO 10545-12): compliant
Modulus of rupture and breaking strength (ISO 10545-4): ≥ 35 N/ mm3
Slip resistance (DIN 51130): R9
Thermal shock resistance (ISO 10545-9): compliant
Crazing resistance (ISO 10545-11): compliant
Linear thermal expansion (ISO 10545-8): compliant