The Serpentine Pavilion is an event space in London’s Kensington Gardens that comes and goes with the summer. But in its short stay it attracts thousands of people and generates international media coverage. It’s a combined gallery, a venue for artistic conversation and performance and a place to just sit, eat and contemplate.
The Pavilion itself is part of the attraction for visitors, for many the star turn. Over the 22 years it’s been built, it’s gained a reputation for ground-breaking design – a showcase for architecture at the cutting edge which reinterprets construction materials and pushes their technical boundaries. And this year it’s very much a showcase for doing that with wood.
The roll call of designers who’ve taken on the Pavilion challenge in the last two decades reads like a who’s who of top rank architects worldwide. Among the big names have been Frank Gehry, Zaha Hadid, Toyo Ito and Oscar Niemeyer.
This year’s building is the creation of French-Lebanese Paris-based architect Lina Ghotmeh and she’s called it À table – the French call to people to sit down together “around the table to engage and participate in dialogue about current affairs, politics, personal lives and dreams while sharing a meal”. A feature of the interior is a concentric table along the perimeter, which is an invitation from the architect to visitors “to convene, sit down, share and celebrate exchanges that enable new relationships to form”.
Ms Ghotmeh has built a reputation for focusing on sustainability and designing spaces “that are conceived in dialogue with their surrounding natural environment”. This is very much the approach for À table.
The 300m2, 4.4m-high building features a structural frame of glulam (GL 30 H) columns and rafters with a central steel supporting ring beam forming an oculus, a circular opening at the apex of the roof. The roof deck is made of plywood sheets with a liquid applied membrane covering on the top surface for weatherproofing. This is supported on plywood purlins spanning between the glulam rafters. The oculus roof covering has a central steel support with a pre-stressed ETFE membrane cover.
Fretted plywood panels sit between the structural columns to form the external façade of the building.
All plywood and glulam surfaces are stained for exterior use and treated with fire retardant, and connections between primary structural elements are principally screw and bolt.
The lightweight structure sits on concrete pad foundations, which are designed to be removable and reusable, and steel is used for other high stress elements, such as the buckling restraint purlins, acting as a flitch beam.
“Built predominantly with bio-sourced and low-carbon materials, this wooden structure emerges in harmony with its site,” said Ms Ghotmeh. “Appearing like a skeleton, timber ribs are arranged radially to support the suspended, pleated roof. Echoing the structures of tree leaves, the Pavilion’s canopy embraces the nature of the park from which it rises. It reminds us of the many lives blossoming beneath our feet and the concave lines of its perimeter are drawn from the forms in the stems and canopies of adjacent trees. It is an encouragement to enter into a dialogue, to convene and think about how we could reinstate and re-establish our relationship to nature and to the Earth.”
The Pavilion was once more prefabricated and erected by Stage One Creative Services, the 14th time they’ve taken on the project.
“Every time we are presented with a radically different design and we appreciate how these architectural plans are experimental,” said managing director Tim Leigh.
“The innovative design by Lina Ghotmeh complements our desire to use more sustainable materials, while also advancing our expertise in mass timber building. This is also the second time we’ve used pre-cast concrete pad for the pavilion, which lowers the total amount of carbon embodied in the project and permits reuse of the same foundation when the Pavilion is rebuilt in its permanent position.”
The engineer on À table – and the previous 10 Serpentine Pavilions – was international consultancy AECOM. It’s always a demanding task due to the fixed budget and short programme of the project. But, said director Jon Leach, this drives “spontaneity, innovation and creativity”.
“Balancing the ability of the architect to freely express their vision with practical cost, buildability, time and functional constraints, as well as the restrictions of working within the Royal Parks is a key challenge that the team embraces every year,” he said.
AECOM commented on the central structural role of timber in the Ghotmeh design. “Steel flitching was only used in very specific areas where it is required to restrain the slender glulam rafters,” said Mr Leach. “The glulam columns work in tandem with the delicate fretwork plywood wall panels to stabilise the structure without the need for any additional bracing.”
The design optimisation process, said AECOM, has minimised material use and allowed every piece of the structure to “contribute to the delicate architectural form”. The result is an extremely lightweight superstructure with minimal foundations, which are weighed down with site-won ballast.
The modular build, with prefabrication at Stage One’s York facilities, was also optimised to minimise waste and to simplify fabrication and erection. Residual timber was chipped and used in the company’s biomass heating system.
The Pavilion has also been assessed from an embodied carbon perspective throughout the design period and all materials were audited to ensure they were ethically sourced from sustainable supply chains.
Another feature of the Pavilion this year will be a range of tables and stools Ms Gotmeh has designed in collaboration with The Conran Shop. These are made in oak with a dark red finish, and 25 of the tables and 57 of the stools will be form a ‘ceremonial display’ inside the structure.
Ms Ghotmeh also highlighted that her building will have a life beyond the brief span of the Serpentine event and that its reincarnation on another site will also be minimal impact.
“It’s designed and engineered so it can be easily disassembled and re-assembled,” she said. “So it will live beyond its Serpentine site, all the while holding the memory of its original ground.”
Serpentine pavilion 2023 designed by lina ghotmeh. © lina ghotmeh architecture. Photo: iwan baan, courtesy: serpentine
