Horizontal division of old building: what the Registry requires in 2026

Key data

Registering a horizontal division of an old building can become an unexpected registration blockage when the registration folio does not record the built surface area of the dwellings on the first and second floors. That is exactly what happened in the case resolved by the General Directorate of Legal Security and Public Faith (DGSJFP) through resolution of June 23, 2026 (published on October 19, 2026, BOE-A-2026-21729).

The property registrar of Alfaro-Cervera del Río Alhama suspended the registration of a horizontal property division deed because the surface areas stated in the deed differed from those recorded in the Registry. Its requirement: to prove the modification of work in accordance with article 28 of the Land Act, providing technical or cadastral certification. The notary appealed arguing that there was no new construction, but merely a descriptive specification of an already existing building, and that the municipal horizontal division license was sufficient to prove urban viability.

What does this regulation establish?

The resolution addresses a technical issue with very concrete practical consequences: when is it mandatory to formalize a new construction declaration prior to the registration of a horizontal division?

The core of the conflict is summarized in the following table:

The resolution determines which of the two positions is correct, with direct implications for notarial and registration practice throughout the national territory when processing horizontal divisions of buildings with incomplete registration descriptions.

Article 28 of the Land Act is the reference regulation: it regulates the requirements for registering construction acts (new construction declarations, extensions, modifications) and requires, in certain cases, technical or cadastral certification that proves the description of the property. The key is whether the update of the surface area in the registration folio—when the building already existed but its surface area was not recorded—constitutes or not a "modification of work" in the sense of that article.

Economic and operational impact

For owners and developers processing horizontal divisions of old buildings, the impact is direct:

• Cost of suspension: A negative qualification from the Registry paralyzes the operation. If a prior new construction declaration is required, the process requires hiring a technician (architect or surveyor) to issue the certification, elevate the new construction declaration to a public deed and pay the corresponding notarial and registration fees for that additional act.
• Time lost: Processing a complementary new construction declaration can add weeks or months to the process, with the consequent delay in sales, mortgage financing or transfers.
• Cost of cadastral or technical certification: If the Registry requires proving the surface area in accordance with article 28 of the Land Act, the owner must obtain technical or cadastral certification that proves the actual description of the property, with the associated professional cost.
• Impact on ongoing operations: Any purchase, mortgage or transfer linked to the elements of the horizontal division remains blocked until the registration defect is resolved.

If the DGSJFP sides with the notary and concludes that the municipal horizontal division license is sufficient, the additional burden of the new construction declaration is eliminated in these cases, reducing costs and timelines for owners.

Who does it affect?

• Owners of old buildings who want to divide them into horizontal property regime and whose registration folio does not record the built surface area of all floors.
• Real estate developers who acquire old buildings for their transformation and commercialization by apartments.
• Notaries who authorize horizontal division deeds and must know what documentation to require to avoid negative qualifications.
• Property registrars who qualify these deeds and must apply the DGSJFP criterion.
• Lawyers and real estate advisors who manage operations on buildings with incomplete registration descriptions.
• Financial entities that finance operations linked to horizontal divisions of old buildings.

Practical example

An owner has a three-story building in a town in La Rioja. In the Property Registry, the registration folio only records the surface area of the ground floor premises; the dwellings on the first and second floors have no recorded built surface area.

The owner executes a horizontal property division deed before a notary, stating the actual surface areas of each dwelling (for example, 85 m² on the first floor and 90 m² on the second). Those surface areas do not match what is recorded in the Registry (which simply does not record any data for those floors).

The registrar of Alfaro-Cervera del Río Alhama suspends the registration and requires that, before registering the horizontal division, a new construction declaration be formalized with technical or cadastral certification in accordance with article 28 of the Land Act. The notary appeals to the DGSJFP arguing that the building already existed, that there is no new work to declare, and that the municipal horizontal division license proves urban viability.

The DGSJFP resolution of June 23, 2026 determines which of the two positions is correct and establishes the criterion applicable to all similar cases in Spain.

What should companies do now?

1. Review the registration folio before executing: Before executing any horizontal division deed, verify whether the Registry records the built surface area of all floors of the building. If there are floors without registered surface area, anticipate the possible conflict.
2. Obtain updated cadastral certification: Request a descriptive and graphic cadastral certificate of the property to verify whether the cadastral surface areas match those that will be stated in the deed. This can serve as supporting documentation before the Registry.
3. Consult with a specialized notary: Before authorizing the deed, the notary must assess whether the building's registration situation requires previously formalizing a new construction declaration or whether the municipal horizontal division license is sufficient, in light of the DGSJFP criterion in this resolution.
4. Obtain the municipal horizontal division license: In any case, prove to the Registry that the City Council has granted the horizontal division license. This document is relevant to argue the urban viability of the operation.
5. Anticipate additional timelines if the Registry requires a new construction declaration: If the operation is linked to a purchase or financing with a deadline, incorporate into the planning the time necessary to process a possible new construction declaration (hiring a technician, public deed, registration).
6. Follow the DGSJFP criterion: Consult the full text of resolution BOE-A-2026-21729 to know the definitive criterion applicable and transfer it to your specific operation.

Official source

Consult complete regulation in official source

Notice: This article is merely informative in nature and does not constitute legal advice. For specific decisions, consult a qualified professional. Source: https://www.boe.es/diario_boe/txt.php?id=BOE-A-2026-21729