Special Award: Best Use of British Timber Winner 2007
Building Owner: The Trustees of Chiddingstone Castle
Architect: Peter Hulbert Chartered Architects
Builder/Main Contractor: IPIG
Structural Engineers: Buro Happold
Joinery: Carpenter Oak and Woodland Co
Wood Species: Chestnut, Oak
The architect was approached in 2004 to look at the sensitive restoration and refurbishment of the Grade I Listed Orangery at Chiddingstone Castle. The building was licensed for weddings, but as the decayed roof had been removed in the 1980s, this made it a rather weather-dependant venue. The client bravely embraced the challenge of a glazed gridshell roof because it was a visually simple solution which allowed us to cover a difficult shaped space with a simple geometric form. The spheroid is both elegant and efficient and does not detract from the impact of the ‘ruined’ orangery, yet is a delicate and sophisticated structure which complements the existing heavy masonry building.
Chestnut, selected for its durability and flexibility, is grown in managed coppices throughout Sussex and Kent, and the suppliers had developed a finger jointing technique which allowed it to be supplied in any length with minimal wastage, and proven performance. The laths are connected using a nodal clamp developed by Buro Happold, which was adapted to carry the glazing brackets, designed to provide large amounts of dimensional tolerance and take up any movement or settlement.
At the perimeter, the laths are blocked into a ply skirt, connected to a ply ring beam, prefabricated into sections to enable easy transport to site. This is further stiffened with steel plates which transfer the load to 10 steel columns which take the roof loads to the ground rather than through the historic fabric of the orangery. The infill between the two structures is clad in copper on the outside and oak slats on the soffit.