A quarter of Second Empire Paris composed from its parts: the Étoile with its twelve avenues and uniform hôtels, a planted avenue driven to the Opéra, a boulevard running from a railway station to a domed church, and every street walled by stone immeubles whose cornices stop at the height the 1859 decree allows.
Between 1853 and 1870 the prefect of the Seine, Georges-Eugène Haussmann, cut some 100 kilometres of new streets through Paris. His memoirs explain the reasoning: straight percées to open the crowded centre to traffic, light and air; to join the railway stations to each other and to the heart of the city; and to give every monument a straight approach and a view (the station at the end of the boulevard, the church across its far end, the Opéra at the head of its avenue). Where streets met, he made places and rond-points; at the Étoile twelve avenues radiate from Napoleon’s arch, their wedges filled with identical mansions by Hittorff.
The streets are uniform because the law made them so. The decree of 1852 let the city take whole plots for new streets, made plans compulsory and required fronts to be kept clean; the decree of 1859 tied the height of a house to the width of its street (20 m to the cornice on streets 20 m wide or more) and bounded the roof by a 45° line. Builders filled the envelope exactly: a shop and entresol in rusticated stone, the étage noble with its continuous balcony, three more floors, a second continuous balcony on the fifth, and the slate or zinc roof with its dormers. The Beaux-Arts buildings, the Opéra above all, stand out against this even ground as the cathedrals of the new city.
This is a composition, not a map: the Étoile, the avenue de l’Opéra and the boulevards Malesherbes and de Strasbourg have been brought together to show the rules at work. Click an immeuble to see its regulation, a monument to see why it stands where it does.