When Heatherwick Studio were told that they needed to be able to open the windows wide in the summer, they certainly took it to heart!
Heatherwick Studio has unveiled its latest project, a kinetic Glasshouse set on the edge of the National Trust’s Woolbeding Gardens, part of a historic estate in West Sussex.
This unfolding structure provides the focal point to a new garden that reveals how much the ancient Silk Route has influenced English gardens of today. It features ten steel ‘sepals’ with glass and aluminium façade which take four long minutes to open, creating an immense 141m2 space in the shape of a crown.
Conceived in collaboration with The Woolbeding Charity and the National Trust, the Glasshouse draws inspiration from the spirit of Victorian ornamental terrariums. It deploys cutting-edge engineering to provide a functional protective structure while at the same time offering a beguiling, decorative element to the new Silk Route Garden.
On warm days, the Glasshouse opens its ‘sepals’ using a hydraulic mechanism to allow the plants access to sunshine and ventilation while in colder weather the structure remains closed providing shelter to a collection of subtropical species.
Thomas Heatherwick said: “This is a place and a project that literally unfolds. You step through this bewitchingly beautiful garden and discover an object that starts like a jewel and ends like a crown, as the Glasshouse slowly unfurls.”
“I think it also speaks of our need to keep creating amazing pasts. Weaving contemporary inventions into the fabric of historic settings and having the confidence to let each one speak to the other.”
The Silk Route Garden surrounding the Glasshouse invites visitors on a 12-step journey through a landscape influenced by the ancient trading route between Asia and Europe where commodities such as the eponymous silk were exchanged and along which many plants species were brought back to Britain for the first time, such as rosemary, lavender and fennel.
A winding path allows visitors to move through over 300 species and twelve distinct regions of the Silk Road. From Mediterranean evergreens where visitors can enjoy a rare variety of Mullein (Verbascum sp.) grown from a seed brought here by a friend of Woolbeding Gardens, through to the richly scented Gallica roses, now so popular in England but originally introduced to Europe by traders from Persia.
The Glasshouse itself shelters an impressive, rare specimen of an Aralia Vietnamensis which provides shade for a collection of tender ferns growing alongside umbrella trees, magnolias and bananas.
“This Heatherwick Glasshouse represents the cutting edge of technical design and engineering but it’s also a restoration of something that is part of Woolbeding’s history,” says Mark Woodruff of The Woolbeding Charity.
“It stands as a crowning achievement in contemporary design, to house the flora of sub-tropical south-west China at the end of a path retracing the steps along the Silk Route, from temperate Europe and across mountains, arid lands and high pastures that brought the plants from their native habitat in Asia to come to define much of the richness and glory of gardening in England.
“Joining the William Pye water sculpture and Philip Jebb’s noble neo-classical folly, both monuments to the fallen great trees that they succeeded, the Heatherwick Glasshouse and new Silk Route Garden imbue Woolbeding with even more delight, beauty and pleasure for all who come to what Disraeli called ‘the loveliest valley in the land’.”
Andy Jasper, Head of Gardens and Parks for the National Trust adds:
“The gardens and parklands of the National Trust are as much about the future as they are about the past. The amazing Heatherwick Glasshouse in the new Silk Route Garden is a fantastic example of this – a wonderful reminder of the historic horticultural legacy we are all so connected to in our gardens today, and simultaneously providing a symbolic reminder of our commitment to and belief in tomorrow.
“The Woolbeding project has been an incredible example of technical and horticultural design brilliance. It’s been fantastic working with Heatherwick Studio, with Stewart Grimshaw and the whole project team, and it’s been an inspiring journey that we hope will equally inspire our visitors. It is a chance not only to discover the many stories of owners, gardeners and designers who left their mark, but also experience the excitement and wonder of new designs and ideas.”
More from the Structural Engineers on the project: Eckersley O’Callaghan
The glasshouse is a steel framed pavilion structure, complete with double glazed cladding panels. The top section of the pavilion, 19 metres tall, has been constructed to permit opening and closing. The sepals then cantilever 15 metres once the structure is opened. The sepals open and close to regulate ventilation and temperature.
Our Structure and Facade teams collaborated closely on the project, looking at choosing glass and coatings that perform efficiently, as well as ensuring the detailing of the glass into the steel frame could suitably accommodate varying movements.
Structurally there are two components to the glasshouse: the fixed base and the moving Sepal; there are ten Sepal’s in all. A strong aspect of the design intent was for the operable sepals to all move ‘simultaneously’. Movement is achieved by 10 hydraulic cylinders moving the sepals around their hinges.
A key issue to understand was the wind loading on the structure and how it would vary as the sepals open. A full wind tunnel test was undertaken looking at eight stages from fully closed to fully open, and an accidental case where one sepal is stuck open.
The inflatable gaskets were designed to achieve optimum watertightness and airtightness performance when the sepals are closed, in particular during the cold months as the glasshouse hosts tropical plants which require controlled conditions.
The key considerations to ensure optimum façade performance included addressing; thermal transmission and condensation, air tightness, water control and solar gain. The requirement to utilise the sun’s energy during the winter to minimise the heating requirements played a role in influencing the initial glass, coating and interlayer selection.
Visiting the Woolbeding Glasshouse and Silk Route Garden
The Woolbeding Glasshouse and the Silk Route Garden are open on Thursdays and Fridays from 28 April to 30 September. Visit the National Trust website for more information.
The photography is by Hufton + Crow unless stated otherwise.
Architect: Heatherwick Studio
Design director: Thomas Heatherwick
Group leader: Mat Cash
Project leader: Stepan Martinovsky
Technical design leader: Nick Ling
Project team: Peter Romvari, Skye Sun, Ross Gribben, Ning Loh
Client: The Woolbeding Charity
Project management: Stuart A Johnson Consulting
Structural engineers: Eckersley O’Callaghan
Glasshouse Detailed Engineering and Construction: Bellapart
Environment engineer: Atelier Ten
Building services engineer: Atelier Ten
Garden design consultant: Great Dixter Charitable Trust
Landscape architects: MRG Studio
Cost consultant: Core Five
Moving structures specialist: Eadon Consulting
Lighting specialist: Light Bureau
CDM: Goddard Consulting
Article courtesy of Heatherwick Studio