The carefully engineered use of timber in this fabric tensile structure system leads to a unique and warm result.
By Frank Edgerton Martin
It’s hard to imagine going to the Greek islands and not wanting to stay outside. The Ostraco Hotel in Mykonos recently added a tensile structure to shade its poolside bar area that heightens the experience of land, sunlight and the surrounding ocean. In deference to the beauty, the setting and the simple white vernacular of Cycladic architecture, the hotel sought a lightweight canopy with minimal visual impact. And, with a nod to the seafaring traditions of the island, they also hoped to incorporate wooden and stainless steel mast-like posts and wires as visible elements.
Argiris Chatzidis is a structural engineer who designed and oversaw the fast-track installation of this unique timber mast and tensile fabric canopy. In 2009, he established his firm Tensis in his hometown of Athens to focus on the custom design and installation tensile membrane structures. Chatzidis explains that because of its appearance, strength and durability, “we prefer using PVC-PVDF lacquered fabric by Serge Ferrari.” For the Ostraco Hotel the firm chose Précontraint 1202 S2 because of its reasonable cost and its translucency to bring a soft, even light to the pool area while minimizing heat and glare. The 1202 fabric is also capable of surviving the hot Mediterranean weather and extreme wind speeds (up to 33m/sec [74 mph]), for which Mykonos is known.
An initial challenge in the project lay in fitting the canopy into an already-built surrounding environment within absolute minimum tolerances. Chatzidis engineered sloping beams that attach to surrounding buildings and distribute most of the canopy’s load into the ground through tensioned cables. This solution allows the structure to seem to float above the landscape and draws the visitors’ focus to elegant crisscrossing cables.
In anticipating a summer season opening of the Hotel, Tensis had a mere six weeks to survey, design, manufacture and install the canopy. The fast schedule meant that site measurements and detail design had to be right the first time. “Connection detailing was a major task and challenge,” says Chatzidis, “as there were nodes where different elements like struts, cables, and membrane plates combined all together in a flitch plate located at various locations along the glulam timber members.”
As an engineer who finds beauty in varied textures and materials, Chatzidis believes timber can work very well as a part of a structural system for fabric. “Although it’s not a homogenous material like steel, it can be used in tensile structures when carefully engineered and detailed, leading to a unique and warm end result.”
From both a design and business vantage, the new 45 sq. m (484 sq. ft.) canopy is a great success. Chatzidis proudly notes that his client now shows the pool to customers and travel agents. Today, with its lovely setting and sheltered pool area, the hotel is becoming a desirable venue for weddings, reunions and other grand events.