From the original plain white tilework and Art Nouveau entrances, the architecture of Paris Métro stations has evolved with successive waves of building and renovation.

After experiments with diverse colour schemes, furniture and lighting, since 1999 there has been a reversion to the original design principles of the network. In parallel, the line 14 has provided an entirely new template for the stations of the 21st century.

Entrances

As with all subway systems, Métro entrances are designed firstly to be visible and recognisable. They feature at least a column and a network map. Decorative styles have changed over the years.

Concept

In 1899, the Compagnie du chemin de fer métropolitain de Paris (the Paris Metropolitan Railway Company, CMP) launched a competition for the street architecture of the soon-to-be-opened Métro. The CMP was concerned to avoid criticism in the context of a backlash against the industrial-style architecture epitomized by the recently built Eiffel Tower. In 1886 Charles Garnier, architect of the Opera, had declared in a letter to the minister of public works that:

The winner of the competition was Henri Duray. The CMP's president, Adrien Bénard, nonetheless favored the municipality architect Jean-Camille Formigé. Later he proposed the Art Nouveau architect Hector Guimard, which was agreed to by the municipality.

Original Guimard style

Guimard designed two types of entrances to metro stations, with and without glass roofs. Built in cast iron, they make heavy reference to the symbolism of plants and are now considered classic examples of French Art Nouveau architecture. 141 entrances were constructed between 1900 and 1912, of which 86 still exist.

The roofed variety, known as an (kiosk), features a fan-shaped glass awning. Many examples also featured an enclosure of opaque panelling decorated in floral motifs (those at Gare de Lyon, now destroyed, and at Hôtel de Ville, now located at Abbesses, did not have panelling). The most imposing of these were built at Étoile and Bastille, on opposite sections of the inaugural line 1. Both of these were torn down in the 1960s. Today only two édicules survive, at Porte Dauphine and Abbesses (the latter having been moved from Hôtel de Ville in 1974). A third, replica édicule was erected at Châtelet in 2000.

The simpler open type of entrance, known as an (enclosure), is framed by a "Métropolitain" sign held between two ornate, sinuously curved lampposts. These are designed strikingly in the form of plant stems, in which the orange lamp is enclosed by a leaf (resembling a brin de muguet, or sprig of lily of the valley).

Later styles

From 1904, the CMP employed the architect Joseph Cassien-Bernard to design a number of new station entrances in austere neo-classical stonework. These can be found near certain important monuments, including the Opéra, the Madeleine and on the Champs-Elysées.

After the end of the Belle Époque, new entrances were entrusted to various architects. These typically feature cast-iron balustrades in an elegant but sober style. Many of the entrances that were built by the Nord-Sud company on the present-day lines 12 and 13 retain elegant Art Nouveau style motifs on the tiling surrounding the walls of the stairwell.

Special cases

A few entrances, for example at Pelleport and Volontaires, are housed in independent buildings. These are generally concrete constructions, and recall the architectural styles of the 1920s and 1930s. Conversely, a number of entrances (Riquet, Pernety) are built into the ground floor of existing buildings.

Signposts

Also known as masts or totems, distinctive Métro signposts were a 1920s innovation of the Nord-Sud company.

In the early years, two styles arrived in succession. The sober but stylish Val d'Osne variant (named after the Val d'Osne iron foundry located in Osne le Val in the Haute-Marne department), visible at Saint Paul, consists of a globe-shaped lamp atop a "MÉTRO" sign surrounded by an ornate cast-iron frieze. These were first erected in 1923. The simpler, Art Deco-inspired Dervaux lampposts (named after their architect) became common in the 1930s, following the contemporary trend away from decorative embellishment. In many cases, the Dervaux lampposts replaced the earlier Val d'Osne signposts, which were seen as heavy and out of fashion.

After World War II, new Métro totems lost their lamps and became progressively simpler. The 1950s style features the familiar "MÉTRO" against a blue ring and a large red "M". In the 1960s, the blue ring was replaced by two stainless steel rings. Subsequent masts have kept these rings, now framing a simple interior-lit yellow "M".

Masts built since 1998 on line 14 are almost entirely novel, featuring a minimalist two-dimensional design but containing a hint of the original Guimard style in their plant-like verticals.

Ticket halls and corridors

Ticket halls are typically found directly beneath the street. In the early years they contained little more than a kiosk for buying tickets, amid spartan decoration. From the 1930s, network maps appeared, including the popular plan indicateur lumineux d'itinéraires, a version with lights to indicate the fastest route to a given destination. From 1946 local street plans were installed, and later food dispensers and telephones. In the 1970s, shops appeared in certain stations where space permitted (for instance, Franklin D. Roosevelt).

Corridors which connect platforms of different lines can be long: near-surface construction means tracks and corridors must follow the streets above, and connecting lines are often situated under perpendicular streets. Only a few stations (for example, Jussieu) feature the cross-platform interchange common in deep underground networks.

Stairways are built to a rigorous standard (steps deep and high) in order to avoid irregularity, often the cause of accidents.

Escalators made their appearance at Père-Lachaise in 1909, and numbered around 15 by 1930. Today over 200 stations are equipped with escalators. In general they only ascend – to the ticket hall, to the street or both in busy stations. Moving walkways similar to those in airports have been installed in the two largest transfer stations where some transfers require walking a considerable distance, Châtelet and Montparnasse – Bienvenüe. At the latter station, a high-speed walkway was in brief operation but has since reverted to normal speed.

Elevators were first installed at République in 1910, following a convention by which the CMP agreed to build them where platforms were situated deeper than 12 m below street level. They are in constant use only at a handful of deep stations, notably Abbesses ( below street level) and Buttes-Chaumont ().

Automatic crowd-control gates known as portillons automatiques were once present in the majority of stations at the end of the corridors leading to the platforms. Introduced from the 1920s to regulate passenger access to crowded platforms, their usefulness was never properly demonstrated and from the 1960s they were withdrawn from service. Most have been dismantled, but non-functioning examples can still be found at Charles de Gaulle – Étoile and Gare d'Austerlitz.

Train halls

Most Paris Métro stations are vaulted. Certain stations were built by the cut-and-cover method, with flat roofs of iron or concrete. Finally, a number of stations are situated above ground on viaducts. The original train hall length was , though this has been extended to on busy lines (1, 3, 7, 8, 9) to allow for 6-car trains. Certain stations were further extended to , the difference as yet being unused.

Types

Vaulted train halls generally comprise two platforms on either side of two central tracks. Exceptions include: Stations on one-way, looped stretches of track, with a single track and platform (example: Église d'Auteuil) Stations that have two platforms, one for each direction, but whose platforms are offset in separate vaults not directly opposite each other, typically because the station is situated under narrow streets (example: Liège) Terminus (or former terminus) stations with 3 or 4 tracks and platforms (example: Porte de la Chapelle) Stations where two lines share a single platform (example: La Motte-Picquet – Grenelle)

The classic station vault is wide and high, including a -thick sill on which the rails are laid. Platforms are wide and separated by a gap. The walls of the stations are slightly curved and their overall shape is elliptical.

Stations on today's line 12, and some of the northern stations on line 13 (Saint-Lazare to Porte de Clichy and Porte de Saint-Ouen) were built by a competing company, the Companie du Nord-Sud. They are larger, allowing for straight walls up to the point where the curvature of the vault begins, and have higher ceilings to provide room for overhead catenaries that have since been removed.

Flat-roofed train halls are of two common types. Early stations built by cut-and-cover (due to tracks being less than below the surface) typically feature roofs of metal beams, which in turn support miniature brickwork vaulting (as at Champs-Élysées – Clemenceau on line 1). The standard hall width is . A second type of cut-and-cover train hall is found in suburban stations built after the Second World War, and has a pure rectangular cross-section and reinforced concrete construction (for example, Malakoff – Plateau de Vanves).

Elevated stations are the signature feature of lines 2 and 6. They are supported by iron columns, of which the exterior masonry features decorative motifs – of the Paris municipality and various wreaths and cornucopia. Stations on line 2 are covered by platform awnings, while those on line 6 have full glass roofs and opaque brick walls decorated on the outside with geometric motifs.

Decoration

Original CMP style (1900–1914) The original decoration of the Métro's underground train halls was austere. Stations featured plain white tiles, enamel plaques for the station name, a few wooden benches and the station manager's kiosk in the middle of the platform. Within a few years advertising billboards and confectionery machines appeared. The now-famous beveled white tiles (of Gien earthenware) were chosen for their effective reflection of ambient light. Early-20th-century electric lighting had a strength of only 5 lux, making it impossible to read a book. Today's fluorescent lighting can reach 200 lux.

Nord-Sud style (1910–1930)

To attract travelers, the Nord-Sud Company, which built what is now line 12 (line A, Porte de Versailles to Porte de la Chapelle) and part of the northern section of what is now line 13 (line B, Saint-Lazare to Porte de Clichy and Porte de Saint-Ouen) chose a more elaborate decorative scheme for the interior of its stations than that of the CMP. Most of the tile was the familiar white beveled type, but the white tile was complemented by arches of colored tile over the vault and garland-like swags on the walls. This complementary tiling was color-coordinated: brown for normal stations, green for terminal and transfer stations, and pale blue for the station Madeleine (the reason for this station's particular color scheme has never been fully explained). These colors matched the colors of the tile borders on the station's poster frames, nameplates and corridors. The most impressive feature of the Nord-Sud stations were the station names themselves, executed in large tile mosaics with white letters on a blue background. Blue and white tiling above the two tunnel entrances also indicated the destination of the trains (for example, "Dir. Montparnasse / Dir. Montmartre" on line 12).