The Museum’s award-winning Downland Gridshell Building was the first timber gridshell building to be constructed in the UK. It is regarded as an iconic building and both architects and other interested visitors travel from across the UK (and further afield) to view this unique example of the technique. Completed in 2002, the building was financially supported by the Heritage Lottery Fund. Visitors to the Museum can take a free guided tour the Downland Gridshell Building and artefact store each day at 2.00pm.
The gridshell is a lightweight structure made of oak laths. The upper deck enclosed by the gridshell is called the Jerwood Gridshell Space, and this is the Museum’s conservation workshop and training space. Its dramatic, light and airy structure also makes the Jerwood Gridshell Space an excellent wedding, concert and performance space. It sits upon a purpose-built lower level, which is home to the Museum’s designated collections of tools and artefacts.
The lower level of the Downland Gridshell Building houses the Museum’s collections of tools and artefacts from rural life in the Weald & Downland region. Agriculture, domestic life, trades, industries and transport are all represented, and there is a special emphasis on building construction and the building trade.
These collections, numbering about fifteen thousand items, are now stored in the purpose-built basement of the Downland Gridshell. Access to the stores is available on guided tours and by appointment with the curator. The basement also contains the Mitford Foulerton Conservation Studio with facilities for research and conservation of the Museum’s collections.
The upper part of the building provides a workshop where historic timber-framed buildings can be laid out for conservation and repair. The size of the space allows for large frames to be assembled, but it will also be used for training workshops and the conservation of large objects.
Building the Downland Gridshell
A gridshell is a structure with the shape and strength of a double-curvature shell, but made of a grid instead of a solid surface. The grid can be made of any kind of material — steel, aluminium, or even cardboard tubes — but the Downland Gridshell is made of slender oak laths bent into shape.
To prepare the oak laths for use all defects were removed and the resulting pieces finger-jointed together into standard lengths of 20 feet (6m). Six of these pieces were then joined to form 120 foot (36m) laths.
The diagonal grid of laths was initially formed flat on top of a supporting scaffold. The edges of the grid were then lowered gradually, and the grid bent into shape, until the full shell was formed and secured to the edges of the timber platform above the basement.
The grid is actually a double layer, with two laths in each direction. This is necessary in order to combine the required degree of flexibility with sufficient cross section for strength. A fifth layer triangulates the grid to increase its stiffness. The laths are connected at the nodes of the grid with a patented system of steel plates and bolts.
The Downland Gridshell is one of a very small number of gridshell structures in Britain, and its design and method of construction are unique. A very high degree of carpentry skill went into its fabrication, emulating but not imitating the traditional framed buildings at the Museum.
The workshop area enclosed by the gridshell is known as the Jerwood Gridshell Space to reflect the Jerwood Foundation’s generous support of this unique building.
- Follow the progress of this exciting project in words and pictures
- Article: Project history and design brief
- Article: Gridshells and the construction process
- Awards, benefactors and donors