With the aim of obtaining up-to-date data on the number of empty flats in each municipality, the Generalitat will work with local councils from next year to mobilize these properties. The project, underway at the International Centre for Numerical Methods in Engineering (CIMNE) in Lleida, uses data on water and electricity consumption, resident registration, and information gathered door-to-door by some councils.
Previously, determining if a property was vacant required an on-site inspection by an official. The new law facilitates councils' ability to ascertain this situation by leveraging available data. The Director General of Housing, Jordi Mas Herrero, emphasizes the importance of activating this underutilized built asset.
The Generalitat does not plan to impose sanctions for keeping flats unoccupied for over two years, as legal proceedings are lengthy and often the property is already for sale or rent by the time they conclude. The focus is on an incentive-based strategy to encourage properties to be made available to society.
Currently, municipalities can apply a surcharge on the IBI (property tax) for homes continuously vacant for more than two years, provided the owner possesses four or more residential properties. Law 12/2023 for the right to housing allows this surcharge to be increased up to 150% in certain circumstances. Thirteen municipalities have applied these surcharges, totaling 106,026.43 euros in 2025.
Another measure in place since 2015 is the tax on vacant homes for large holders with over 15 properties unoccupied for two years. The revenue from this tax was nearly 3 million euros in 2025, with funds allocated to increasing the purchase of flats for social rent.
Some municipalities, such as El Prat de Llobregat and Olesa de Montserrat, are implementing measures to attract vacant flats, offering tax benefits, rehabilitation subsidies, and legal and financial security to owners in exchange for placing them on the rental market at below-market prices.
Official data from the INE's population and housing census in 2021 indicates 417,652 vacant homes in Catalonia, based on electricity consumption. While the methodology is interesting, the Director General of Housing notes that the 2020-2021 data, coinciding with the pandemic, might be affected by temporary population movements. More recent data from large holders in 2024 registers 25,443 declared vacant homes.
