Landmarks: Bibliotheque Saint-Genevieve, Paris

My chosen building is called the Bibliotheque Sainte-Genevieve in the Place du Pantheon in Paris, designed by Henri Labrouste between 1843-50. Part of the Sorbonne, on the outside it is a quite austere, strictly classical building with very large semi-circular headed windows.

Labrouste belonged to the Rationalist School who were interested in stripping away classical ornaments and basically leaving as much building as you needed. Yet while it has this rather bleak outside, the interior has an incredibly delicate, light, cast-iron structure. The main reading room is huge, divided in half by 16 beautifully decorated cast-iron columns which are very slender and fluted. The plain barrel-vaulted plaster ceiling is supported by very ornate, semi-circular trusses, also in cast-iron, decorated with a pattern of leaves and flowers.

When I was there last Easter it was stuffed with students which was wonderful. There it was, this building which is 150 years old and it's so popular you could hardly get in.

It was the first public building to use cast-iron from floor to ceiling and they got very good at it. Labrouste became interested in the synthesis between art and construction: he was taking a material which had previously been used for utilitarian buildings like mills and factories and applying it to the art of architecture, to say, 'This can be beautiful too.' The buzz I get from it is walking into this wonderful interior having been fooled by the classical exterior: it hits me every time.

Paul Notley is a partner with Lyster Grillet & Harding, London. Photo by Hazel Cook

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