Unité d'Habitation Case Study: Section, Plans and the Modulor (Le Corbusier)

The Unité d'Habitation in Marseille is a block of about 337 dwellings that Le Corbusier built for the French state between 1947 and 1952. Students study it for three ideas: two-storey flats that interlock around a corridor on every third level, a building lifted on pilotis over an "artificial ground", and a whole block proportioned with the Modulor. Below: the brief, site, plan and section, structure, materials, climate, reception and lessons for India.

The brief and the client

After the Second World War, Raoul Dautry, minister of Reconstruction and Urbanism, gave Le Corbusier his first public commission. The Fondation Le Corbusier's project page dates the order to 20 July 1945 and its 70th anniversary note to 30 November 1945. The Docomomo register entry explains the gap: an informal request in summer 1945, and the official letter on 27 December 1945.

It was state rental housing, an "immeuble sans affectation individuelle" (a building not allotted to individual owners). Docomomo records 321 flats and 16 hotel rooms, 337 units in all, with shops, laundries, a restaurant and a hotel: the "prolongements du logis", or extensions of the home. The flats were 45 per cent larger than the housing norms of the day. Malcolm Millais, in a 2015 paper in the Journal of Architecture and Urbanism, gives the target as about 1,600 residents, and notes that Le Corbusier told Dautry in 1944 he would accept only if he did not have to follow all the building regulations.

Site and context

The block sits at an angle on a roughly square plot about 200 m a side. Its long axis runs north to south, so the long facades face east and west; the south gable has loggias and the north gable is blind (Docomomo). Because it stands on pilotis, the park runs on underneath it. Most flats run right through the block, so they get morning light on one side and evening light on the other: "bathed in light from sunrise to sunset", in the Fondation Le Corbusier's words.

Concept: a vertical village

Millais traces the section to two unbuilt Le Corbusier schemes, Geneva (1929) and Nemours (1934), and to Moisei Ginzburg's Narkomfin building in Moscow. The concept has four parts:

• A neighbourhood in one block: shops and a hotel halfway up, a nursery school, gym and running track on the roof.
• The five points, plus one: pilotis, free plan, free facade, long windows and roof garden, with the brise-soleil (a fixed concrete sun-breaker) added as a sixth (Millais).
• The flat as a standard part: every dwelling is built from the same narrow cell.
• One system of measures: the Modulor, which ATBAT and the studio used here for the first time (Docomomo).

For the five points themselves, see our Villa Savoye case study in this series.

Unité d'Habitation plan and section: how the duplexes interlock

Docomomo describes most flats as two-storey and "traversants": they run from the east facade to the west. The standard type is for four people: a living room open to the kitchen, a parents' bedroom and two children's rooms split by a movable partition. Other types range from singles to families with six to eight children. Docomomo and the Fondation Le Corbusier count 23 types; the Ministry of Culture's heritage record and Millais count 15. Millais adds that 199 of his 335 flats are the standard type.

The trick is how two flats share one corridor:

1. The internal street runs down the middle of the block on one level.
2. One flat enters from it and climbs to an upper level that spans the full width.
3. The flat opposite enters from the same street and drops to a lower level that spans the full width.
4. Each has a double-height living room at one facade, so the pair locks together like two L shapes.

The result is one corridor for every three levels, with every flat reaching both facades. Docomomo gives the cell as about 3.66 m wide inside and 2.26 m high, rising to 4.84 m in the double-height part of the living room.

Circulation and zoning

Docomomo counts 18 levels served by seven internal streets at levels 2, 5, 7, 8, 10, 13 and 16, each a lift stop. Levels 7 and 8 hold the shopping street, which runs half the length and looks out through vertical concrete fins instead of loggias. Read from the ground up, the block has five zones:

• open ground under the pilotis
• the artificial ground, a walk-in service deck
• flats on 17 levels
• shops at mid-height
• a roof terrace with a crèche, a kindergarten with a paddling pool, a gym, a 300 m running track, an open-air theatre and a solarium

For Le Corbusier's own plans and sections, start from the Fondation Le Corbusier's project page; Docomomo names its Paris archive as the holder of the drawings. A reconstruction of a standard flat has been shown in the modern gallery of the Cité de l'Architecture et du Patrimoine in Paris (Delemontey). Our guide on how to document a building for a case study shows how to turn these into sheets a jury can read.

Unité d'Habitation structure: pilotis, artificial ground and the bottle rack

Docomomo describes four parts, all in reinforced concrete cast in place: foundations; pilotis, 34 piers on 17 portal frames 8.38 m apart; the artificial ground, a deck of beams that technicians can walk inside, holding the air plant, lift machinery and standby generators; and a post-and-beam frame that carries the flats. Millais adds the grid, 4.19 m by 4.19 m. The pilotis stand in pairs on every other grid line, 8.38 m apart along the block and 12.57 m across it, and one standard flat fills one 4.19 m bay.

The "bottle rack" (casier à bouteilles) is the idea behind the frame: flats slotted into a rack like bottles. Millais records that the first version, introduced by Jean Prouvé, was a steel rack holding flats made in a factory. Steel was short after the war and sliding in whole flats proved impractical, so the frame became concrete and the flats were built in place.

Docomomo credits the flats' quiet to lead pads between the flats and the frame. Millais, working from site photographs, says the lead was not installed as drawn. Treat the pads as design intent.

The Modulor

The Modulor is Le Corbusier's scale of measures based on the human body, set on a man 1.83 m (six feet) tall, according to the Fondation Le Corbusier's glossary. Michael Ostwald's review in the Nexus Network Journal explains its two series: red from the navel of the figure with raised arm (1.13 m), blue from the raised fingertips (2.26 m). That is why the flats are 2.26 m high. Some books say the whole building used only 15 Modulor measurements; Millais disputes this, pointing out that even the 4.19 m grid is not a Modulor dimension.

Materials and construction

The frame is cast in place and most of the rest is precast: facade cladding, balcony brise-soleil, stairs and the walls of the flats (Docomomo). Inside each flat, floors are timber panels on steel beams (Millais). The concrete was left as struck from the formwork, béton brut, and colour went onto the loggia walls in red, green, blue and yellow. Close to 40 firms worked on the site.

The figures on time and money:

• Time: 12 months planned, 60 taken.
• Cost: estimated at 353 million francs in 1947. In 1953 the Cour des comptes, France's audit court, put it at 2,800 million and Le Corbusier at 2,095 million (Docomomo).
• Legal fights: a 1949 lawsuit by the Société pour l'Esthétique de la France tried to stop the work. Millais records that France's public health council advised stopping it in 1948, partly because 2.26 m ceilings were below the legal minimum; a ministry waiver in July 1949 freed the project from needing a building licence.

Light, climate and services

Each flat ends in a full-width glazed wall onto a loggia shaded by brise-soleil. The Fondation Le Corbusier's intent: block the summer sun, let the winter sun in through double glazing. Millais doubts it works here. Horizontal sun-breakers suit a south facade, but these face east and west, where the low summer sun gets under them, and he reports that almost all residents fitted roller blinds.

Heating was ducted warm air from eight fans in the artificial ground, fed through ducts cast into the concrete walls, and kitchens, bathrooms and WCs were mechanically ventilated to a stack on the roof (Millais). The deep plan had a cost: kitchens sat nearly 8 m from a window, one reason the health council objected.

Reception: praise, lawsuits, repairs and the 2012 fire

The Fondation Le Corbusier calls the block "a founding work of Brutalism". When UNESCO listed it in 2016 with 16 other Le Corbusier works in seven countries, Anna Winston of Dezeen called it "arguably the most influential Brutalist building of all time". Millais collects both sides of the critics: Kenneth Frampton (2001) wrote that never was "the utopian modern project so convincingly and thoroughly realized"; Lewis Mumford (1963) said Le Corbusier "betrayed the human contents"; Peter Blake (1974) called it "a spectacular hunk of sculpture".

Yvan Delemontey's history in Docomomo Journal 54 (2016) sets out the residents' problems:

• Early years: leaking facades and roof, and a warm-air heating system that kept failing.
• 1961 to 1974: the co-owners went to court. In 1962 Le Corbusier conceded it was "an extremely powerful building but delicate in terms of technique".
• 1986 to 1996: after classification, a first campaign repaired the facades and roof structures.
• 2001 onwards: the west facade was restored, the roof terrace re-waterproofed (2008 to 2011), and the east facade begun in 2015.

Docomomo names one root cause: reinforcement placed too close to the concrete surface corroded and burst it. Delemontey adds the sea air and faults in placing the concrete. Docomomo adds that high service charges made regular upkeep hard.

On 9 February 2012 a fire destroyed 8 duplexes, 2 studios and 2 hotel rooms, by Delemontey's count; Millais gives 8 flats and 4 hotel rooms, with about 30 more damaged by smoke and water. Both point to the timber partitions and the shared ducts, which Millais says had no fire dampers. The flats were rebuilt to their original layouts between September 2013 and autumn 2014, with Perriand's kitchens and Prouvé's stairs reproduced and fire protection added.

Did it fail? As a home, no: it is lived in and listed. As a prototype it fell short. Millais counts 68 Unité schemes, of which five were built; the other four are at Rezé (1953 to 1955), Berlin (1956 to 1958), Briey-en-Forêt (1958 to 1961) and Firminy (1964 to 1967), per Docomomo. Millais says the shops struggled because only residents used them. Today the tourist office lists a hotel, a restaurant, a bookshop and galleries on the shopping levels, and the MaMo art centre in the old roof gym.

What designers in India can take from it

This is our reading, not the sources'.

• Borrow the skip-corridor section for mid-rise housing. Fewer corridors mean fewer lift stops, and every flat gets two opposite facades: in humid Mumbai, Chennai or Kochi, that means cross-ventilation a flat off a double-loaded corridor cannot have. Fire-stop every shared duct: the 2012 fire spread through them. Our note on small apartment design trends shows the flat sizes buyers now expect.
• Match the shading to the facade. Horizontal brise-soleil on east and west walls let the low sun under. On Indian east and west faces, vertical fins, deep loggias or jaalis do more; keep horizontal projections for the south.
• Put shared shops where people already pass. Shops on level 7 relied on residents alone. In Indian group housing, shops belong at the gate or street edge, and roofs and podiums suit residents' facilities.
• Exposed concrete by the sea needs cover and a maintenance fund. Specify cover, grade and coatings for coastal exposure, and plan who pays for upkeep. Our guide to building near the sea in India covers the detailing.

For a housing thesis, the Unité pairs well with an Indian public housing scheme; our B.Arch thesis topics by typology lists housing briefs that suit the comparison.

Visiting the Unité d'Habitation

The Marseille tourist office runs guided visits that include a listed flat, with booking for individuals and for groups of 10 or more. Without a guide you may see the public areas: the shopping streets, part of the roof terrace and the 2.8 ha park. Respect the residents, and check the tourist office page for times and prices.

Want to see how Indian architects design housing today? Browse projects by MOA members.

FAQ

When was the Unité d'Habitation built?

The foundation stone was laid on 14 October 1947 and the building was inaugurated on 14 October 1952. It was commissioned in 1945; sources give July, November or December.

Who designed the Unité d'Habitation?

Le Corbusier, working through ATBAT with André Wogenscky and the engineer Vladimir Bodiansky. Charlotte Perriand designed the kitchens and fitted interiors, and Jean Prouvé's workshops made the steel floor frames and stairs inside the flats.

How many floors does the Unité d'Habitation have?

Docomomo counts 18 levels including the roof terrace, served by seven internal streets. Millais describes it as seventeen storeys, counting the levels below the roof.

What are the dimensions of the Unité d'Habitation?

About 137 m long (135 m in the Fondation Le Corbusier's figure), 24 m wide and 56 m to the roof terrace. A standard flat is about 3.66 m wide inside and 2.26 m high, with a 4.84 m double-height living room.

How many apartments are in the Unité d'Habitation?

Docomomo counts 337 units: 321 flats and 16 hotel rooms. The Fondation Le Corbusier gives 330 dwellings and Millais 335 flats. Sources count either 23 or 15 flat types.

Sources

• Fondation Le Corbusier: Unité d'habitation, Marseille, France, 1945-1952 (accessed 3 Nov 2026)
• Fondation Le Corbusier: The Unité d'Habitation de Marseille turns 70 (accessed 3 Nov 2026)
• Fondation Le Corbusier: Vocabulaire corbuséen (accessed 3 Nov 2026)
• Docomomo France: International register entry, Unité d'Habitation de Marseille (rapporteur Catherine Le Teuff) (accessed 3 Nov 2026)
• Ministère de la Culture, DRAC Provence-Alpes-Côte d'Azur: Marseille 8e, Unité d'habitation Le Corbusier, dite Cité Radieuse (accessed 3 Nov 2026)
• Yvan Delemontey, Docomomo Journal 54 (2016): The Marseille Unité d'Habitation after Le Corbusier: Or the Chronicle of a Permanent Construction Site (accessed 3 Nov 2026)
• Malcolm Millais, Journal of Architecture and Urbanism 39(2), 2015: A critical appraisal of the design, construction and influence of the Unité d'Habitation, Marseilles, France (accessed 3 Nov 2026)
• Michael J. Ostwald, Nexus Network Journal 3(1), 2001: Review of The Modulor and Modulor 2 (accessed 3 Nov 2026)
• Dezeen, Anna Winston: UNESCO adds 17 Le Corbusier projects to World Heritage List (19 Jul 2016, accessed 3 Nov 2026)
• Office de Tourisme de Marseille: La Cité radieuse, Le Corbusier (accessed 3 Nov 2026)