Context and Origin
The report “Transformer des bâtiments non résidentiels en logements” is part of the Éclairages series (issue 36, June 2026) published by Banque des Territoires, the financing arm of Caisse des Dépôts. It is produced by the research chair Le Logement demain, coordinated by Anne D’Orazio and Anne‑Laure Jourdheuil, with contributions from Alexandre Coulondre, Claire Juillard, Fanny Lefebvre, Thomas Armanet and Francesco Bogoni. The study builds on a research programme launched in 2022 that analyses the transformation of non‑residential assets into housing across France.
Scope of the Study
The document reviews past transformation projects (2013‑2023) using the Sitadel2 database, distinguishing two definitions: TAL (Transformation d’Activités en Logement) covering all activity spaces, and TTL (Transformation du Tertiaire en Logement) limited to tertiary premises such as offices, public services and hotels. It quantifies the number of operations, surface areas involved and resulting housing units, while also examining feasibility criteria and future potential.
Key Results – Volume and Growth
- 99 200 TAL operations produced 241 800 logements; 12 800 TTL operations produced 122 900 logements.
- Average annual output: 22 000 logements (TAL) and 11 200 logements (TTL).
- Transformation rate grew from 18 000 to 25 000 logements per year (TAL) and 8 000 to 13 000 logements per year (TTL), reflecting annual growth rates of 3 % and 5 % respectively.
- TAL accounts for 5.4 % of total residential production; TTL for 2.7 %.
- Typical project size: 2.4 logements (TAL) and 9.6 logements (TTL).
- Sector breakdown (TAL): 22 % agricultural, 10 % warehouses, 24 % offices, 12 % commerce, 14 % public services, 9 % hospitality.
- Sector breakdown (TTL): 40 % offices, 27 % public services, 17 % hospitality, 13 % commerce.
Feasibility Criteria
The authors list fifteen criteria that influence success, including urban‑plan compatibility, ownership structure (monopropriété), market‑driven vacancy length (2‑4 years), structural suitability (height < 15 m, floor‑to‑ceiling ≥ 2.5 m), compliance with fire‑safety, acoustic and accessibility standards, realistic renovation cost (≈ €2 500 / m² SHAB for offices‑to‑housing), and the presence of a genuine residential demand. Financial viability also depends on the price differential between non‑residential and residential rents and on the willingness of insurers to cover transformed assets.
Potential for Europe
France’s office stock totals 173 million m², with 9 million m² (≈ 5 %) currently vacant. Of this, 2 million m² have been empty for over two years, representing a theoretical maximum of 39 200 new homes (using the study’s 51 m² office‑to‑housing ratio). Government plans cite 25 000 units in the short‑term and 70 000 in the medium‑term, while the authors extrapolate a continued output of ≈ 27 000 units per year if the 5 % annual growth persists. Similar conversion opportunities exist in other European markets where office vacancy rates have risen post‑COVID‑19, suggesting that the French experience can inform broader sustainable‑housing strategies.
Sustainability Implications
Transforming existing structures avoids the embodied carbon of new construction, reduces land consumption and supports circular‑economy principles. The report notes that re‑usable building shells can lower overall lifecycle emissions, especially when combined with energy‑efficient retrofits (e.g., achieving DPE C or better). Financial instruments such as the Prêt de Haut de Bilan 2.0 and the TRANSFO+ scheme provide low‑interest or interest‑subsidised loans, further aligning economic incentives with environmental goals.
Concluding Facts
- Total of 2 million m² office vacancy suitable for conversion.
- Potential creation of 15 000 – 25 000 logements annually across France.
- Key actors: public owners, private investors, social‑housing organisations.
- Regulatory support includes the Daubié law (2025) and ELAN flexibilities.
- The study underscores the need for coordinated municipal planning, targeted financing, and design for reversibility to maximise sustainable housing outcomes across Europe.