At a special event on June 17, the museum will celebrate the building, its architecture and the people involved in constructing the UK’s first major timber gridshell building.
The day will feature a programme of presentations, group discussions and exhibitions as well as giving guests the chance to meet and talk to key members of the team involved in the ground-breaking project.
Museum director Simon Wardell said: “The Gridshell is a jewel in our crown here at the museum.
"It’s regarded as an iconic building and attracts visitors from around the world to view its spectacular and unique construction.
"We are delighted to be able to mark this anniversary with the building and engineering communities as well as our museum members and other interested members of the public.
"We are looking forward to reuniting some of the talented team that came together two decades ago to create a UK first.”
There will be talks from key members of the original team about the concept, design and construction as well as informal group discussions on topics such as carpentry and structural engineering led by experts in the industry.
Group tours of the museum’s artefact store will also be taking place throughout the day.
The rest of the museum will be open for guests to explore including the Downland Gridshell Exhibition, the reference library and many of the historic homes and buildings.
The Gridshell Building was completed in 2002 and was supported by the Heritage Fund and Jerwood Foundation, with support from a range of other funders.
The iconic building was the first timber gridshell in the UK and won both the Royal Institute of British Architects’ Regional Architecture Award and the British Construction Industry Award in the same year.
Taking just one year to complete, the building derives its strength from its double curvature and is made with a grid or lattice design using green oak.
Over the past 20 years the 12,000sqm Gridshell has been used as a conservation centre and artefact store within the museum, and to host various special occasions.
To find out more or to book tickets for this event, please visit www.wealddown.co.uk