It is less than a week since the fire at Notre Dame Cathedral and the response has swung from global grief at an architectural tragedy, to relief that the damage was not as extensive as it could have been, and on to matters of reconstruction. President Emmanuel Macron has announced that the 13th-century landmark will be rebuilt within five years, “even more beautifully”.

Macron’s words accompanied the announcement of an international competition to design a new spire and roof structure – boosted by €1bn of private donations pledged so far. The prime minister, Édouard Philippe, said they hoped for “a new spire adapted to the techniques and the challenges of our era”.

President Emmanuel Macron speaks to Parisian firefighters on Thursday. Photograph: CHRISTOPHE PETIT TESSON/EPA

What might that mean? Among other things, a once-in-a-lifetime opportunity for architects and designers. The 90-metre (300ft) spire was one of the most familiar landmarks on the city’s relatively low-rise skyline. Added in the 1850s by Eugène Viollet-le-Duc, it was itself a replacement for the original 13th-century spire, which had become so battered it was removed in 1786. A new spire will be more prominent still. But what should, or could, a new addition look like?

Norman Foster, founder and chairman, Foster and Partners

Notre Dame Cathedral is the ultimate high technology monument of its day in terms of Gothic engineering. Like many cathedrals, its history is one of change and renewal. Over the centuries, the roofs of medieval cathedrals have been ravaged by fires and replaced: for example, Chartres in 1194 and 1836, Metz in 1877. In every case, the replacement used the most advanced building technology of the age – it never replicated the original. In Chartres, the 12th-century timbers were replaced in the 19th century by a new structure of cast iron and copper. The decision to hold a competition for the rebuilding of Notre Dame is to be applauded because it is an acknowledgement of that tradition of new interventions.

Sir Norman Foster. Photograph: Alamy

As an aside, the roof that has been destroyed had wooden frames – each was made from an individual oak tree – 1,300 in total. Hence its nickname, “the Forest”. It was rarely visited so, surely, this is an opportunity to recreate a once-hidden – and now destroyed – timber structure with a modern, fireproof, lightweight replacement. The ideal outcome would be a respectful combination of the dominant old with the best of the new.

Robert Adam, founder and director, Adam Architecture

I suppose people are saying now it’s burnt down, you’ve got to put in something contemporary. Bollocks! It is not a building, it’s a cultural artefact. It’s a symbol of Frenchness. Architects get this silly idea that because technology changes, therefore architecture always ought to reflect those changes. But culture – how we think of ourselves, how we identify ourselves – does not move quickly; it moves very, very slowly in fact. And to confuse these two things is a serious mistake.

They should do what they did at York [Minster, which suffered a similar fire in 1984] and put it back so that people wouldn’t actually notice. There is this crazy idea that any replacement or new work should have a “contemporary stamp”, and this is generally interpreted to mean things need to look different in order to show people that they are modern, because it would be terrible if people were confused. Well, I don’t see why it’s so terrible. Who are you actually catering for? Are you catering for the most stupid, visually illiterate person? In which case you have to make it look so obviously unlike what was done before that they couldn’t possibly make a mistake. Or if you are an expert and you go to York Minster you will know straight away what is new.

To apply ridiculous modernist theory to this would be so culturally disruptive as to be damaging.

Martin Ashley, conservation architect specialising in historic buildings.

Martin Ashley. Photograph: Linda Nylind/The Guardian

Would it be possible to rebuild Notre Dame’s spire exactly as it was? In theory, yes. Being a spire, it’s quite a complicated structure, but I imagine it was pretty well recorded in various digital and photographic surveys. As to whether the craft skills exist to do it? Yes, absolutely. The carpentry, the metalwork, the roof cladding is all achievable again.

But in a way, restoration is a form of destruction. In restoring buildings, you destroy the history that has gone before. What the people of Paris should now do is something of this time and this culture, and adds a new chapter to that chronology which is enshrined within the historic building fabric of the cathedral. It is an opportunity to do something which is deeply contextual, very dignified, very appropriate, very spiritual, but different.

Amanda Levete, founder and director, AL_A

History never stands still. Notre Dame took centuries to build. The fire is now a part of that history. In a sense the identity of Notre Dame is more located in the two towers, the rose windows, the gargoyles – and therefore the spire is a natural position for something that is expressive and symbolic of something else.

Amanda Levete of AL_A architects. Photograph: Karen Robinson/The Observer

The question is, what is the expression of who we are now? Or who the French people are now? What does it represent? Who is it for? Notre Dame was built at a time when the church was the state, and it’s clearly not now. This building belongs to France, it’s the soul of France, faith or no faith.

With our extension to the Victoria & Albert Museum we took a radical view in terms of what we proposed. We had a responsibility to protect the building’s heritage but on the other hand to breathe new life into it and keep it relevant. That power of difference is not a modern idea. We need to be confident of where we are and to celebrate not just the present but to look to the future.

Stephen Barrett, partner, Rogers Stirk Harbour

We applaud in the French their relationship to modernity, which has enabled practices like our own to make a contribution there in ways that would probably be more problematic in London, say. The Pompidou Centre was also an open competition. Two young architects [Richard Rogers and Renzo Piano] won that and it changed their lives.

Seeing those images of the cathedral with no roof also reminded me of Coventry Cathedral: there was something extraordinary about having sight of the sky. I think today you could do something very light and transparent with the roof, which would have its own potency. All kinds of qualities would emerge.

Whatever is built, there has to have incredible lightness, an incredible economy of means, so doing something with almost no material, which is very much the challenge of our age, even in the broader sense of frugality and resource scarcity – but also to have a luminosity to it. It needs to be a kind of beacon.

Ptolemy Dean, surveyor of the fabric, Westminster Abbey

Everybody will be focused on “what’s the new spire going to be?” But actually we really must try to focus on conserving what’s already there first of all. We don’t want to lose the original Gothic vaulting inside. That then leads to what the roof space is used for. It’s a great big void in the upper storey of the cathedral and the question to my mind is, is there anything ingenious that could be done with it?

Ptolemy Dean, Westminster Abbey. Photograph: Helen William/PA

Then finally we’re left with the whole question about the spire. To me, it’s a slightly deeper question than putting something in and making it a statement of modern thought; I think it’s also tied to the functionality of that roof void. You could make something rather amazing in there that explains the whole story of the fire and reveals something about the Gothic vaults.