Palace of Westminster - Westminster Hall
Palace of Westminster - Westminster Hall
We have worked as structural engineers at the Palace of Westminster - the Grade I, UNESCO World Heritage Site that serves as the centre of Government - for over thirty years, through a series of successive framework commissions.
Our work has involved the restoration of the Westminster Hall roof, which was completed in 2020. The hall received worldwide attention in 2022 when it served as the location for Her Majesty, Queen Elizabeth II’s lying-in-state.
Westminster Hall was originally completed in 1097 before being rebuilt in the late 14th century at the request of Richard II. The timber hammer beam roof is a remarkable survival of medieval carpentry, constructed with a clear span of 22m. With thirteen 660-ton timber arches, it was the largest spanning structure in Britain for five hundred years.
During its repair, each rib of the roof was found to be made up of 9 - 15 individually hand carved timbers, which in many instances had to be carefully disassembled to allow the removal and (sensitive) replacement of early resins, of heartwood eaten away by deathwatch beetle attack, charred timber dating from bombing during the 1970s.
Our work included developing the concepts for how to undertake conservation works to the medieval timber whilst ensuring that the hall could be rapidly returned to use in the event of an unplanned state function. Our solution was to suspend scaffold ‘boats’ from the roof, that could be winched up into the shadows of the roof profile and out of sight at a moment’s notice.
The subsequent repair approach to the medieval trusses involved the skilled use of traditional carpentry methods and physical fixings to provide reversible and honest repairs to the structure. The lead-clad timber roof lantern was also re-detailed and repaired, using salvaged materials where possible, and requiring specialist carpentry work.
The project won a Wood Award in 2023, with the judges commenting that “this heritage project has expertly conserved Westminster Hall’s exquisite medieval hammer beam roof and repaired its gothic roof lantern…the repair approach to the medieval trusses involved the skilled use of traditional carpentry methods and physical fixings to provide reversible and honest repairs to the structure.”
Client: Parliamentary Directory Estates
Architect: Donald Insall Architects
Photos: Main image ©Adam Watrobski / Other photos © Donald Insall Associates