Westminster Abbey is a textbook of five centuries of architecture; the glorious Decorated geometry of the apse, the last gasp of Perpendicular glory in Henry VII’s chapel, the Baroque-Gothick games of the west towers, Gilbert Scott’s Hollywood fantasy gothic in the North Transept. But all these glories converge on nothing more than a strange stubby little pyramid blob. It was stuck on the central tower in the 1950s after the Luftwaffe had contributed their own airborne explosive criticism to the Abbey. It sort of works as a moment of cool Early English pause between the firework displays of the East and West ends. But no-one would describe it as exciting, unless they had a particular fetish for the Pizza Hut logo.

Now the Dean and Chapter have decided that something more regal, pompous and festive should symbolise the site where Kings and Queens have been crowned- and what better than a corona? My first thoughts were that this might be hamfisted architectural literalism at its worst. “It’s where she gets crowned, so why don’t we put a really big crown there, geddit?”. But a moment’s reflection reminded me that this has worked ever since an unknown Roman stuck transepts on the side of a church nave and suddenly realised that he had a crucifix built of stone four hundred feet long. There’s nothing wrong with the idea- we just need to make sure of the execution.

I would love to see a richly coloured stained glass crown-lantern. It should bathe the interior of the Abbey crossing in purple, green and red. It could echo the design of the coronation crown itself, and set off the gold pinnacles of the Palace of Westminster. Perhaps something half-way between Ely Cathedral’s lantern and the gruff spikery of St Giles’ High Kirk, Edinburgh. It should be simultaneously surprising, joyous, counter-cultural- but also glorious, pride-instilling and sure of its own thousand-year roots.

The new corona would be a symbol that Westminster Abbey isn’t just a historic monument, and it certainly isn’t just another Cathedral. It straddles the gap between cloister and palace, Church and State. After the inward-looking monasticism of its first half millennium came to an end, it flung its doors open and found a new role as national parish church. It’s now so jampacked with tombs and memorials that it reminds me of an enormous family chapel. Some of them are of beloved parents like Shakespeare, Handel, Newton. Others are little-known embarrassing distant cousins. All are part of the family- and the Abbey should emphasise that we're all part of the family too.

A word of warning. In 1665, some other clerics had the idea of sticking a new excitingly modern cupola on their old, much loved mediaeval London church. And so Sir Christopher Wren came up with a plan to shove a dome with an enormous gold pineapple on the top of Old St Pauls. But the Great Fire of London had other ideas…