STON, officially OFS STON, is a state-approved organisme de foncier solidaire (OFS) based in Toulouse, France.15 It is a société coopérative d’intérêt collectif established in 2022 at the initiative of Procivis Sud Massif Central Toulouse Pyrénées and its subsidiary Sud Massif Central Habitat.2 The organisation is part of the Procivis group and focuses on social homeownership through the bail réel solidaire (BRS), a legal arrangement that separates ownership of the land from ownership of the building.21
STON acquires and manages land, develops housing programmes under the BRS system, sells homes to eligible households, and monitors compliance with the rules governing occupation, resale and the lease.4 As an OFS, it retains ownership of the land over the long term rather than operating solely as a conventional property developer.4 Its programmes are intended to make homeownership more accessible by reducing the price paid for the housing unit.1
The organisation’s primary area of activity is Toulouse and its metropolitan area, with programmes located in several municipalities in Haute-Garonne.48 Its corporate registration records describe a broader activity covering the Occitanie region, but its public-facing housing activity is concentrated on the Toulouse urban area.511 Examples of its programmes include Respire in Toulouse-La Vache, Apostrophe in Croix-Daurade and Vista Verde in Casselardit.4
As of 31 December 2025, OFS STON reported 257 BRS homes across 16 operations, including 153 reserved and 106 completed through signed transactions.2 The organisation’s LinkedIn page identifies it as created in 2022; its registered office is at 181 Route d’Albi in Toulouse.35