A year after fire ravaged Notre-Dame de Paris, a TV documentary shows encouraging signs of progress in a reconstruction project that raises both structural and philosophical problems, says Donald Insall


The excellent BBC documentary on the post-fire rescue work at Notre Dame, ‘Rebuilding Notre Dame: Inside the Great Cathedral’, has presented us all with a welcome window on progress in Paris, and an engaging report on the advancing rescue work now in hand. For me, it also brings back lively memories of some very similar issues raised in the restoration programme at Windsor Castle, following the fire in 1992.


Top: Notre-Dame de Paris ablaze in April 2019
Above: Donald Insall Associates’ restoration of Windsor Castle following the 1992 fire

The immediate and outstanding impression given is the remarkable thoroughness of research, and the absence of financial restraints in what is now being so energetically undertaken in Paris. Items like the selection of matching sources of stone, and the pursuit of sufficient oak for the accurate reconstruction of the celebrated ‘foret’ of the ancient oak roof lost in the fire, are being energetically undertaken. Research has revealed the existence of a relatively recent all-timbers architectural survey, invaluable in guiding its reconstruction. We do not know what decisions have been taken about a restoration to any particular date in the long history of the cathedral, and whether in particular the focal nineteenth-century fleche by Viollet-le-Duc will be accurately reinstated.

The immediate support of the cathedral’s iconic flying buttress system has been carried out by inserting temporary wooden arches; and no doubt measures are being taken to check any residual movement which may still be happening. But the structural identity of its Gothic cage-of-forces is in this way already safely and effectively assured. The stone vaulting, with its thrusts which they counterpoise, will thankfully now in the main be secure, and the continuing concern must now be its protection from unaccustomed exposure and weather. Effective rainwater disposal will be only part of the protection now so essential. Removing the tangled mass of metal scaffolding which surrounded and embraced the spire can next proceed; and one wonders to what degree the fire was spread by the wooden boarding which its task was to carry.


Reconstruction work at Notre-Dame de Paris

Fascinatingly, the celebrated stained glass windows of the cathedral were miraculously preserved, suffering less damage than was initially feared, and thanks as it seems to deposits of protective dust and maybe also of candle-wax, deposited over so long a time.  The problem now remaining will be not only how to clean and restore them, but then how to protect so precious a feature from the continuing dust and damage of an active building site. We did not at Windsor so much realise any significance of airborne dust and lead deposits, or their kindly function as well as their dangers. All the hose-water, retained by plaster on the castle’s inner walls, is thankfully less of a problem here with exposed stone surfaces.

The damaged upper cathedral stonework, scorched by flaming roof timbers, will also be the subject of a current every-stone survey to enable a considered programme of individual masonry replacement and renewal. Coordinating all these different trades and activities will be a major riddle to solve. A further practical problem is the ever-present if unmentionable danger of another fire.

A brilliantly restored Notre Dame may have to reflect the fact that a copying and partial reconstruction of any damaged historic monument now has its own and honourable identity, and can never again be all of its original date”

At Windsor and by comparison, we were all working within very constricted financial limits and controls, requiring a perhaps more pragmatic and less idealistic approach. We were in consequence driven very early to identifying and considering the philosophical problems of renewal-versus-replacement. One recalls the philosophical ‘Options Study’, very early undertaken by our Royal Household and agreed by English Heritage and its consultants, a parallel to which may still perhaps be in hand by our French professional cousins.   This it was which guided us in taking the infinite number of clamouring daily decisions called for in considering the degree to which non-original replacement materials might still be employed, wherever the passage of time rendered precise replacements uneconomic or unavailable. The undeniable truth remains that a brilliantly restored Notre Dame may similarly have to reflect the fact that a copying and partial reconstruction of any damaged historic monument now has its own and honourable identity, and can never again be all of its original date.

The function of all buildings does develop and colossally change with time. It may be that positive and practical enhancements are possible – one bears in mind the vastly improved circulation system at Windsor, or even the new lifts installed there and at Westminster. Although this may come as a shock for some, it might not be too early to review the daily issues which encumber any building owner; and the daily handling of visitor and tourist issues is not to be ignored, if the cathedral and all its supporting functions are to survive and prosper.

The technical questions and management problems of such a complex project as this, always immense, will have been amplified by the physical situation of the building on a tightly-built island in the river Seine. Programming, deliveries and mutual interference of all the practical tradeswork involved will present a severe headache. But the skill and devotion being evidenced in these earlier stages of the rebuilding are a huge comfort and encouragement in the progress of such a complex and challenging project – perhaps the greatest of its kind in this century.

The film itself is excellent, and as open-handed as the works so proudly displayed. Diagrams and models are used to great effect, and one’s only concerns are some occasional false-flame effects which perhaps unnecessarily detract a little from the hungry and devouring selfishness of the real ones. Commentary is clear, and one can only wish that Windsor had been able to share its lessons with equal promptitude, skill and generosity.

Fire is Man’s worst enemy; and what we also constantly need is the best of advice on actual prevention, avoiding altogether the occurrence of such terrifying events as these.

‘Rebuilding Notre Dame: Inside the Great Cathedral’ can be viewed on BBC’s iPlayer until 15 May.