12 years ago, I found immense joy in designing a set of architectural sails at the French Riviera. The project is situated on a promontory, an iconic place on one of the capes protruding into the Mediterranean Sea. Now, 12 years later, the sails give me again immense joy because they still look stunningly beautiful and really clean. The global choices of the design, the choice of materials, the detailing, the patterning, everything still looks fresh, well maintained and joyful.
Membrane projects don’t have to be big or huge to give aesthetic pleasure and fulfilling.
Small projects can be very challenging and complex too.

Small projects can be very challenging and complex too.

Small project, big details

What I personally like about small projects is the need for refined detailing because everything is literally near to the eye of the user. Each small detail is important because each stain or dirty blur is directly seen from within a near distance. In large projects, details tend to fade away in the total appearance of the project.

One of the difficulties of smaller projects is the patterning. In large-scale projects, the individual strips of textile making up the big curved surface are in itself not very complex in terms of curvature. However, the individual patterns of smaller pieces of tensile architecture are rather complex. Compare it to an arch: a big arch spanning 5 meters can be constructed with a rectangular brick, but the bricks of a small arch are usually more trapezoidal in shape. The scale is important to the curvature and its detailing of the individual parts making up the total curved shape.

The essence of tensile architecture is to make a span with a minimum of materials. It is clear that, in this specific case, the economic effect of a minimum of materials is not great, on the contrary: the cost of studies to make such a complex construction are relatively high in comparison to a classic construction. But the reason to choose for a tensile is aesthetical: the clients absolutely wanted to have a clear panoramic view on the surrounding beauty of the sea, without too many masts and cables in the way. A classic construction would not allow that. The appearance and emplacement of the masts and cables were extremely important. Also note how the sail is curving around and embracing the existing trees and architectural context. The form of the membrane is ‘free’, the impact of masts and cables are minimal.

But it is not only an aesthetical affair: the membranes must withstand the very harsh weather of this sea climate, with very high wind loads, a salty, hot and humid climate during summer, freezing temperatures in winter. Severe storms with spraying salty water occur regularly. That means that the stainless-steel masts, screws, corner plates and cables have to be of the best quality and that they have to be treated properly after handling or manufacturing (by passivation and electropolishing). During installation all the materials have to be manipulated carefully to avoid contamination of the stainless steel by iron parts or instruments.

The fabric is woven in PTFE garn with a coating of PTFE (Sefar Tenara). It is 40% or 20% translucent, chosen for different parts of the sails according to the desired effect. As I did a check-up last week, the fabric is intact, white, clean, perfectly maintained. Even the nasty glue of the pine trees can be washed away thanks to the coating. The picture below shows the project in a state of 12 years old.

“A thing of beauty is a joy for ever” (John Keats, 1818) But if the membrane starts to be greenish and dirty after some years, and if the stainless-steel parts and masts become rusted, the joy is quickly over and does not stay for ever at all. To the contrary: cheap projects with poor materials are a frustration forever.
After 12 years, this particular project can be showed to the world with pride.

Key necessities for a successful membrane, small or big:

• A good design with a good understanding of optimised curved organic forms is fundamental
• A brilliant engineer with lots of experience in this specific field.
• Trustworthy companies who deliver good certified materials, and no cheap rubbish
• Trustworthy certified manufacturers who understand the importance of each detail
• A careful installation:
  • the anchors are of capital importance for the security
  • handling stainless steel parts carefully is important to avoid contamination
  • in tensile structures, each detail is fundamental
• A perfect maintenance