Comment on: The romantic and pragmatic history of the fan vault has lessons for contemporary structures
The author says, seemingly to assert axiomatic principles about Fan Vaults that:
"Instead of razing the churches completed after the Norman Conquest and rebuilding in the Gothic, they modified and added to these existing structures to create fan vaults as a decorative layer within. "
This point seems to be at variance with history, as three of the finest examples of Fan Vaults are King’s College, Cambridge, Bath Abbey(essentially a new-build) choir and Henry VII’s chapel in Westminster Abbey, though the latter is a fan-pendant, while Eton College chapel was designed to have fans which were not instated at the time. The cloisters of Gloucester are also new-build, though on old foundations.
"The fan vault sheltered religious belief and benefaction on a local scale and required a separate roof to shed the rain."
All gothic vaults in stone required an outer roof, with lead or other impervious cover.