Update of Order ECO/805/2003 and new features of Order ECM/599/2025.
More than two decades after its entry into force, the regulation that regulates the valuation of real estate, Order ECO/805/2003, has been modified to include new considerations adapting to the reality of the current market. These modifications seek to streamline urban management, incorporating the validity of administrative authorizations prior to the building license for the appraisal, and emphasizing the inclusion of sustainability and environmental factors, such as energy efficiency and climate risks, in the valuation of properties, given its growing influence in the market.
In this article, we detail exclusively the new features proposed by Order ECM/599/2025, published on 12 June 2025, for its entry into force two months later.
The modification of the ECO Order: how does it affect the valuation of properties?
The purpose of Order #ECO is to establish the technical rules and procedures (scope of application, principles and definitions, checks, conditions and warnings, methodology and documentation) for the calculation of the value of real estate when the appraisal is used for the purposes established therein. among others, the mortgage guarantee for the granting of a mortgage. Therefore, its application is mandatory when applying for a loan for the purchase of a home or other type of property.
The proposed modifications seek to improve transparency, legal certainty, efficiency in the appraisal process and technical uniformity, adapting to regulatory dynamics and the growing importance of sustainability in the real estate sector.
Five main new features in the regulations on the appraisal of real estate: Order ECM/599/2025
The main novelties include:
1.- Sustainability is part of the value of the property
One of the novelties is the incorporation of a new principle in valuation, #PrincipiodeSostenibilidad. In other words, the value of the property can be affected upwards or downwards by the impact of environmental factors, climate risks or energy efficiency.
This means that it is not only a matter of reducing the levels of pollution and energy consumption of a property, but also of its water consumption, the type of waste generated, the protection of biodiversity, adaptation to climate change or risk of fires or floods. The Energy Performance Certificate (EEC) will also be incorporated as documentation attached to the appraisal report whenever available.
2.- New administrative authorizations for the start of the work: more agility to assess construction without conditioning
Until now, in order to be able to appraise a property under construction in the hypothesis of a finished property, for the purposes established in the ECO, including mortgage purposes, it was mandatory to have the corresponding urban building license. However, some municipalities have created new administrative figures prior to this license, such as administrative authorizations for the start of the work.
ECM/599/2025 recognises this type of authorisation as valid for appraisal, provided that they meet certain requirements: obtaining the building licence a posteriori, accrediting urban planning compliance, authorising at least 60% of the budget for the material execution of the project and the registration in the Land Registry of the declaration of new construction under construction.
What does this imply? Developers will be able to start the work and access financing earlier, without having to wait for the final urban planning license, provided that all the requirements are met. For buyers, it can translate into more available supply and lower costs in the early stages of the project, postponing certain expenses.
3.- More clarity in appraisal reports
The recent amendment to Order ECO/805/2003 also introduces formal improvements to make appraisal reports clearer, more complete and easier to understand:
All signatories must use electronic signatures. Incorporate the electronic signature process also for the professionals who prepare the report, ensuring that everyone endorses its content and guaranteeing traceability. The possibility of counting, as valid documentation in the appraisal for mortgage guarantee, the photocopy of the Land Registry book and that of the property deed is eliminated. The original or copy of a simple registry note, issued within the three months prior to the valuation date, is required. An index is incorporated at the beginning of the report, for easy location. The definition of usable area is modified to explicitly exclude outdoor spaces. Priority is given to the valuation referring to the verified useful area, requiring justification if different areas are used. In addition, spaces that, due to their use, construction and functional characteristics, have independent value (such as storage rooms, garages or premises) must be valued separately, indicating the criteria followed.4.- Greater transparency in the use of witnesses and comparables in the comparison method
From now on, when using the comparison method – the most common in real estate appraisals – it is required that:
Indicate where the witnesses used come from, i.e. the source (real estate portals, registers, etc.). The traceability of the most relevant characteristics of each comparable or control is guaranteed. Justify why each one has been weighted more or less. The methodology and metrics used to determine the applied homogenization coefficients are explained. The use of a surface other than the proven useful area is justified. It is indicated whether the homogenization is carried out in unit value (€/m2) or in total value of the property.5.- Automated valuation methods
Order ECM/599/2025 incorporates a new article on automated valuation models (AVMs) for the purposes of RDL 24/2021 on covered bonds in the case of updating the value of real estate guarantees.
It establishes that they must be for homogeneous properties and in active markets, with a solid and documented methodology. The application of this article will be developed by means of a technical circular by the Bank of Spain.
These updates have been applicable since August 12, 2025 in all appraisals.
SOURCE: Article published by Tinsa by Accumin.
