Overview of the Report
The document “Conversion of offices into affordable housing” is a final report prepared by Lisa Graaf, Emily Bankert and Zsolt Toth for the European Commission’s Directorate‑General for Environment (ENV.B). Published in October 2025 by the Business and Policy Institute for the Environment (BPIE), it analyses how repurposing vacant office buildings can contribute to Europe’s affordable‑housing challenges while supporting climate goals.
Why Conversions Matter
Europe faces a combined housing shortage and high office vacancy rates, especially after the COVID‑19 pandemic. Converting existing office stock can quickly increase affordable supply, reduce embodied carbon, and avoid urban sprawl. The report highlights that office‑to‑housing conversions can be up to four times less carbon‑intensive than demolition and new construction, with potential annual CO₂ savings of 9.2 million tonnes by 2045.
Key Findings on Feasibility
- Conversions retain structural elements, lowering embodied emissions by 60‑80 % compared with new builds.
- Cost comparisons show mixed results: German studies find conversions cheaper (€1 281/m² vs €3 405/m² for new builds), while French and UK analyses suggest higher costs. Four completed case studies (Ireland, France, Spain, Belgium) achieved lower or equal total costs to comparable new‑build projects.
- Energy performance improvements are common; examples include a 72 % reduction in energy use in Barcelona (below 20 kWh/m² yr) and A‑class ratings for many Irish units.
Case Study Highlights
| Country | Project | Units | Year | Notable Features |
|---|---|---|---|---|
| Ireland (Cork) | Springville House | 35 | 2023 | Age‑friendly design, rightsizing scheme, garden with accessible picnic tables |
| France (Marseille) | Rue Acquaviva | 24 | 2019 | BBC renovation label, added balconies, low‑carbon materials |
| Spain (Barcelona) | Carrer del Pla 2F | 34 | 2022 | Emergency housing for vulnerable groups, natural ventilation atriums |
| Belgium (Brussels) | Pavillon 7‑9 | 41 | 2021 | Mixed‑use ground floor, lightweight timber extension, EPC B rating |
Technical and Regulatory Insights
- Building‑code gaps (acoustics, fire safety, minimum daylight) increase conversion costs; flexible permitting can mitigate delays.
- Zoning flexibility proved crucial: Cork benefitted from an existing conversion permit; Barcelona and Marseille faced no major zoning hurdles; Brussels secured a permit within 11 months versus the typical 2‑3 years.
- Public procurement that prioritises reuse, as in Brussels and Barcelona, encourages conversions.
- Tax and VAT treatment remains a barrier; office‑building taxes often remain higher than residential rates during conversion phases.
Financial Landscape
- Public subsidies covered 10‑16 % of total investment in the four completed projects.
- Favorable loan terms from public banks and low‑interest “green” financing were essential.
- The Budapest “Affordable Housing for All” initiative, funded by the European Regional Development Fund, exemplifies blended financing for conversion projects.
Policy Recommendations for Europe
The report proposes eight priority actions for EU, national and local authorities:
- Prioritise conversions over new construction in housing and climate strategies.
- Develop EU‑wide methodology to map vacant office stock.
- Create a quick‑check assessment tool for conversion suitability.
- Adopt neighbourhood‑based approaches to make publicly owned vacant offices available for affordable housing.
- Adapt building regulations to ease conversion requirements (e.g., parking, façade preservation).
- Fast‑track zoning and permitting while safeguarding public interest.
- Expand tax credits, grants and low‑interest loans for conversion projects.
- Consider taxes on long‑term vacant offices, exempt during conversion periods.
Collaborative Path Forward
The authors stress the need for coordinated action across European platforms (Covenant of Mayors, EUKN, New European Bauhaus) to share best practices, up‑skill the construction sector, and align funding mechanisms. By scaling office‑to‑housing conversions, Europe can simultaneously address housing affordability, climate mitigation, and urban regeneration goals.