Orangery, Prague Castle
The Renaissance Orangery building on this World Heritage Site collapsed and was replaced by a lightweight glass and stainless steel hothouse. The structure was conceived as an infinitely extendable grid shell of cruciform components with the peculiarities of site and environment accounted for in an asymmetrical supporting frame. The ancient north wall is protected by a prismatic girder eaves beam and the vault is divided by three movement joints to allow for the extreme temperature swing in Bohemia. The envelope of heat strengthened glass divides the outer lattice and inner frame. A standard connection was developed through prototype testing at the Czech Technical University. A single central bolt draws a resilient hook assembly onto the member ends so that tension, compression, shears and bending are all resisted. The slight give in the hooks ensures that all four junctions are firmly made.