Overview
- DGFiP confirmed a 2026 data “fiabilisation” that recalculates taxable surface by counting water, electricity, WC, bath or shower, and heating or air‑conditioning as fictive square metres.
- Affected owners face an average €63 increase, with roughly €466 million in additional revenue expected for local authorities.
- About 25% of houses and 15% of apartments will be revalued, with strong regional disparities such as over 60% of dwellings in Haute‑Corse and about 10% in Isère.
- The additions will be applied automatically without a new owner declaration, with limited advance notice and messages expected in impots.gouv accounts from June 2026 for those most affected.
- Owners whose homes lack the listed installations can contest and seek relief, while unions warn of social impact on lower‑income households and potential legal challenges.