This indicator is exclusively applicable to properties entering the rental market for the first time, those that have not been available for rent in the last five years, or those managed by large landlords (owners with five or more properties). Other rental agreements are exempt from this calculation.

The measure, outlined in the 2023 Housing Law, is restricted to municipalities designated as stressed areas. In Bizkaia, this includes Bilbao, Barakaldo, and a district of Galdakao, while in Álava, it applies to Vitoria. The index establishes a price range for each property, setting the maximum value at which an owner can rent out their home. Its application is street-specific, rather than based on broader zones or neighborhoods.

For instance, a flat at number 68 on Bilbao's Gran Vía could be rented for between 1,331 and 1,658 euros. On Somera Street, in the Old Town, a property with similar characteristics would fall between 815 and 1,026 euros, and on Zabalbide Street in Santutxu, the rent would range from 731 to 954 euros. In Barakaldo, a property at number 1 on Paseo de los Fueros could reach a maximum of 989 euros, while in Aperribai (Galdakao), the range varies between 622 and 754 euros.

According to data from the Ministry of Housing, rents in Bilbao typically range from 700 to 950 euros, with 800 euros being the most common price. In Vitoria, rents fluctuate between 624 and 813 euros, with 706 euros as the usual cost. It has been argued that the inability to arbitrarily increase prices will provide “greater stability for tenants” and “humanize the housing market”.

In addition to Bilbao, Barakaldo, and the district of Galdakao, the Basque Government is considering activating stressed zones in Sopela, Urduliz, Gorliz, Elorrio, Bermeo, and Lekeitio.