AVM tools: automated valuation models for flats in Spain (2026)

The market for automated valuation models (AVMs) for property in Spain has grown significantly in recent years. It's no longer the preserve of big banks and investment funds: private investors, estate agents and buyers have access to tools that used to cost thousands of euros a year. Here is an honest review of what each one offers.

The main AVM valuation tools in Spain

Idealista.com (free valuation): Spain's biggest property portal offers a free valuation tool based on its own listings data. Accuracy is good in areas with a lot of activity, but it has the bias of working only with asking prices (not real transaction prices), which tend to be higher than actual sale prices.

Fotocasa (price estimate): A similar feature to Idealista's, built into its portal. Useful as a second opinion and to check against Idealista. The differences between the two tools for the same property are usually in the order of 3-8%.

Catastro.minhap.gob.es: The Catastro (Spain's property cadastre) reference value is not the same as market value, but it works as a lower bound. Since 2022, the Catastro reference value (valor de referencia, not to be confused with the valor catastral or cadastral value) has been used as the minimum taxable base for ITP (Impuesto de Transmisiones Patrimoniales, the property transfer tax) and ISD (Impuesto sobre Sucesiones y Donaciones, inheritance and gift tax), so it matters for tax purposes.

RadarPro (built-in AI valuation): Aimed specifically at opportunity assets (auctions and bank-owned properties), RadarPro combines AVM valuation with an investment score, analysis of charges on the property and market data for the area. It lets you compare the listed price with the estimated value and the expected rental return.

How to cross-check results between tools

No single tool is "the truth". The most reliable protocol: get valuations from at least two different tools, add your own search for active comparables on portals (3-5 similar properties in the same area), and calculate a weighted average. If the three sources converge on a similar range, you can be highly confident. If they diverge a lot, you need to understand why before making a decision.

When not to trust any AVM

AVMs lose reliability in: very rural areas with few transactions, unique properties (towers, masías or Catalan farmhouses, castles), assets with hidden charges or legal problems, and markets whose trend is changing very quickly (data updated with a delay).

Try RadarPro: Go to RadarPro for AI valuation specialised in opportunity assets, or read the step-by-step guide to using valuation tools.