To unify a façade of two or more storeys, run a single order of pilasters or columns through all of them, from the base to the main cornice.
Rules · Cities · Façades · Roofs
Height from the width of the street
Tie the height of every house front to the width of its street: on streets 20 m wide or more the cornice may stand at 20 m, on narrower streets lower; above the cornice the roof must stay inside a line rising at 45°.
street ≥ 20 m → cornice ≤ 20 m; street < 20 m → cornice ≤ c. 17.5 m (older rule); roof inside 45°
Paris had fixed maximum heights since 1783–84; the 1859 decree raised the limit for the new boulevards and defined the roof envelope. Builders filled it exactly, which produced the standard Haussmann immeuble: a rusticated ground floor and entresol for shops, the étage noble with a continuous balcony, two more storeys, a fifth with another continuous balcony at the cornice line, and one or two storeys of attic rooms in the 45° roof behind a row of dormers.
A rule that relates height to street width keeps light in the street, and it makes the street a room of constant proportion; later codes, from New York’s setbacks of 1916 onward, descend from it.
Related rules
Understand every building as a combination of four elements (the hearth, the roof on its supports, the enclosure and the mound), each descended from a craft: ceramics, carpentry, weaving and masonry.
Break the slope of the roof on all four sides: a steep lower slope, nearly a wall, which holds a storey of rooms lit by dormers, and a shallow upper slope, often invisible from the street.
lower slope ≈ 60–75° · upper slope ≈ 15–30°
Do not leave the fronts of houses to the whim of each builder: let the authorities fix their line, height and design so that a street or square is composed as a whole, and vary the designs from one street to the next so that uniformity does not become tedium.
Cut new straight streets through the old city to join its railway stations to one another and to its centre, and end each one on a monument (a station, a church, an opera house) so that it has an object as well as a use.
Build every house on a new street to the same alignment, in dressed stone, with its floors, balconies and cornice at the levels of its neighbours, and keep the fronts clean, so that the street reads as a single wall.
Cite this page Chris Paton, “Height from the width of the street”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/paris-1859-height. Text, drawings and models licensed under CC BY-NC 4.0.