# The Marseille Unité’s béton brute and sealed-slab type become a model of high thermal mass and isolation from street energy of mixed cities

Date: 1952

## The fact

The 1952 Unité is a heavy concrete ship with brise-soleil, an interior street, and a roof deck — a sealed envelope against the Mediterranean and against the boulevard. He did not write a 2020s energy code. Archival locator: Ville de Marseille — official portal at https://www.marseille.fr/ (Ville de Marseille). Independent locator: Fondation [Le Corbusier](/people/le-corbusier) — English portal at https://www.fondationlecorbusier.fr/en/ (Fondation Le Corbusier).

## Context

Not cosmetic twins: different mechanisms. Firminy and Berlin Unités are later copies/neighbours, not extra 1952 Facts. Archival locator: Ville de Marseille — official portal at https://www.marseille.fr/ (Ville de Marseille). Independent locator: Fondation Le Corbusier — English portal at https://www.fondationlecorbusier.fr/en/ (Fondation Le Corbusier).

The welfare reading used in this dossier is worsening. That reading is an impact-path choice, not a property stored on the Fact itself.

## Evidence and sources

Marseille’s city portal independently locates the building. Fondation independently documents the construction. Britannica independently treats Unité as type. No unique 1952 energy bill is invented. Archival locator: Ville de Marseille — official portal at https://www.marseille.fr/ (Ville de Marseille). Independent locator: Fondation Le Corbusier — English portal at https://www.fondationlecorbusier.fr/en/ (Fondation Le Corbusier).

Official or archival record: Ville de Marseille — official portal (https://www.marseille.fr/; Ville de Marseille).

## Significance

A concrete housing type as resource-and-climate object is a modest energy path. Medium/low confidence on unique performance; high on 1952 as type date. Later retrofit programmes are not 1952. Archival locator: Ville de Marseille — official portal at https://www.marseille.fr/ (Ville de Marseille). Independent locator: Fondation Le Corbusier — English portal at https://www.fondationlecorbusier.fr/en/ (Fondation Le Corbusier).

Shared responsibility is part of The Marseille Unité’s béton brute and sealed-slab type become a model of high thermal mass and isolation from street energy of mixed cities. Naming Le Corbusier does not delete co-authors, institutions, or later transmitters. The lag from 1952-10-14 to any measured indicator is not treated as zero. Alternative explanations — weather, other armies, later statutes, or independent cultural change — remain live where the sources do not close them.

## What is established and what is not

Established: 1952 Unité envelope as his type. Not established: a unique kWh series. 14 October 1952. Not a 21st-century energy audit as the act. Archival locator: Ville de Marseille — official portal at https://www.marseille.fr/ (Ville de Marseille). Independent locator: Fondation Le Corbusier — English portal at https://www.fondationlecorbusier.fr/en/ (Fondation Le Corbusier).

If a number is not in the two records named above, it is not supplied here.

Later competitions, monuments, translations, UNESCO listings, museums, and adaptations are not converted into extra lifetime acts.

Confidence is stated on the impact path, not hidden in adjectives. Mixed effects of The Marseille Unité’s béton brute and sealed-slab type become a model of high thermal mass and isolation from street energy of mixed cities are separate paths.

## People

- Le Corbusier: https://factrail.ai/people/le-corbusier

## Drivers

- Energy Security: https://factrail.ai/drivers/energy-security

## Sources

- https://www.marseille.fr/
- https://www.fondationlecorbusier.fr/en/

## Methodology

https://factrail.ai/methodology

Canonical: https://factrail.ai/facts/lc-unite-energy-isolation