Unusual constructs Garsington Opera pavilion
Garsington Opera has moved to the estate of Wormsley in the Chiltern Hills, home of the Getty family, after 22 years at Garsington Manor. Wormsley is located on the Oxfordshire - Buckinghamshire border in a parkland setting of approximately 2,500 acres.
Garsington Opera instructed architect Robin Snell and, following a competitive tendering process, appointed Unusual Rigging, as main contractor, to manage this design and build project, including fabrication and construction of the pavilion. At the end of the opera season, the pavilion will be dismantled and loaded by crane onto some 40 trucks to be taken away for storage, ready for return next year.
Lifted above the ground to give an appearance of 'floating' over the landscape, Snell's design takes its cue from a traditional Japanese pavilion in its use of sliding screens, extended platforms, verandas and bridges to link it to the landscape.
Project manager for Unusual Rigging, Mark Priestley, says, "We won the project in October, then had until April to coordinate the design and build and manage the logistics, including all ground preparation works. The pavilion sits on 100 permanent concrete foundation bases, each of which measures up to 3sq.m and has an adaptor plate to which the steelwork connects, ensuring an accurate and repeatable set-out each year. The pavilion has a modular steel frame and an overall expected 15 year life span; it will return to the same position each year, enabling the company to make this investment in demountability.
"Construction of the primary structure and fabric roof took a month, with a further month of electrical, timber and seating fit out. Up to 15 of our people were on site at any one time, working with a 65 ton crane. In addition to the supply of rigging, lighting trusses and chain hoists, which is our regular 'bread and butter', we supplied, cut and fitted all the timber - 3km of oak panelling and 13km of balau for the hardwood decking, held together with 70,000 screws.
"The pavilion was designed in a modular format, so each piece of the jigsaw was designed and built off site, then fitted together at Wormsley. Just like a theatre set, each piece is numbered and mapped, so that when it's deconstructed it can be easily fitted back together next year. And each one can be removed individually so that other pieces can be fitted in - such as elements of a set, or to create trap doors in the stage. We were careful to leave large areas around and underneath the stage area free of structural supporting steelwork, so that the directors can take out panels as they wish."
Around 145 tons of steel, supplied by Sheetfabs of Nottingham, make up the pavilion's frame, with some pieces preclad with timber and palletised. The PVC roof, supplied by Architen Landrell Associates, is actually two skins - a waterproof inner skin, with a PVC mesh 100mm above, so that falling rain drips through silently, rather than hammering the ceiling. "As far as we know," says Priestley, "this solution is unique to the pavilion, and works really well. Clear PVC fabric in sail like shapes is used to form the sides of the auditorium.
"The auditorium ceiling and walls were specially designed by Sound Space Design, to improve the room acoustic. In the orchestra pit, we were given designs for acoustic panels, which we fabricated and placed on moveable frames. Even the disabled access lift, which was supplied by Ability Lifting Solutions, is designed to be dismantled for storage in two parts."
The stage is on an elevated position adjacent to Home Farm, with a cluster of flinted buildings that includes a house, barns, orchard, lawns, stables and estate yards.
"The biggest challenge was the timing of the project," explains Priestley. "We had a relatively short le