The Cadastre and the Building File: Two Records, Two Purposes

Picture a buyer in the kitchen of a farmhouse, a printed drawing in one hand, counting doors and tracing walls with a finger. Room by room, the drawing and the house agree. It is a satisfying moment, and it concerns one record only.

How do the two records compare?

They are kept by different bodies for different purposes. The cadastre, the catasto, is kept by the Agenzia delle Entrate, the Italian revenue agency, comparable to the IRS in the United States or HMRC in the United Kingdom. It records each unit’s identification, category, size and cadastral income, and the holders named in the cadastre. The building file is held by the comune, the municipality, through its building office. It records the permits and notifications for building work, and the consents attached to them.

The documents differ as well. On the cadastral side they are the visura (an extract), the planimetria (the plan of the unit), the map and, for buildings with several units, the unit list and plan, known as the elaborato planimetrico. On the building-file side they are the building titles and their drawings. The Court of Cassation calls the cadastral rule one of essentially fiscal purpose.^[1] The building file answers a different question: whether the building, and each later change, was authorised.

Changes are filed in different ways too. In the cadastre they are filed by the holders of rights in the property, through a qualified technician.^[2] In the building file they are filed by the owner or the person entitled, through the procedure for the works.

What does the cadastre show?

The cadastre describes a property so that it can be identified and taxed. A visura gives identifying and income data, the cadastral holders, and the protocol number and date of each update filed. Visura data are public. The plan shows the layout of the rooms, normally at 1:200, and it can be consulted only by the holders of rights in the property, their delegates and others entitled to see it.^[3]

Anyone who holds a right over a building that is registered must declare changes to it in the cadastre. The declaration is prepared by a qualified technician, an architect, engineer, geometra or other listed professional, using DOCFA, the software and procedure for cadastral filings. It is due within 30 days from the date the building becomes usable or, for a unit already registered, from the completion of the change.^[2]

Not every change has to be filed. The Agenzia’s 2010 circular states that a change of a door or partition that alters the floor area of rooms but not their number or function has no cadastral relevance.^[4] A significant redistribution of internal space, or a change in the use of a balcony or terrace, requires a filing.^[4]

What does the building file show?

The building file is held by the comune. Its building office, the sportello unico per l’edilizia (SUE), is the single point through which applications, notifications and related consents for building work pass.^[5] The file shows what was authorised for a building and for each later change. It does not show what the cadastre records.

Where do the two records meet?

They meet in the legitimate state of a building, the stato legittimo. Since the 2024 “Salva Casa” amendments, the building code defines it as the state set by the title under which the building was built or legitimised, or by the title for the last building work covering the whole building or unit, provided that the municipality checked the earlier titles when issuing it, together with any later titles for partial works.^[6][7] Titles issued after a regularisation count, after payment of the related sanctions or fees, and so does the technician’s declaration on tolerances.^[7][8]

For buildings from a period when no building permit was required, the legitimate state is taken from the first cadastral survey or from other documents of proof, such as photographs, map extracts, archive documents or another deed of proven origin, together with the title for the last work on the building.^[9] This is where the cadastre is used as planning evidence: for old rural buildings, the earliest cadastral records may be part of the proof. Deviations in the common parts of a building do not count against the legitimate state of a single unit, and deviations in a single unit do not count against the building.^[10]

The Ministry of Infrastructure’s January 2025 guidelines add two points. The check of earlier titles is met if the last title was issued after a procedure in which the municipality could verify them. And differences not raised when earlier titles were issued cannot later be treated as a lack of legitimate state.^[11] The guidelines are informative and not binding.^[11] The rules described are those in force on 30 September 2026; they were amended in 2024 and may be amended again.

Where can the two records differ?

A cadastral mismatch and a planning mismatch are separate matters with separate remedies.

A cadastral mismatch means that the plan or category in the cadastre does not match the building as it stands. The remedy is a cadastral update filed by a technician. It changes the record, not the planning position. The Court of Cassation has said that the cadastral rule applies whether or not the present state of the building resulted from work that was lawful in planning terms.^[12]

A planning mismatch means that the building differs from its title. Two provisions of the building code matter most. The first is tolerances. A deviation in height, distances, volume, covered area or other parameters of a unit is not a violation if it stays within 2% of the measures in the title. For work completed by 24 May 2024, higher limits apply according to the useful surface of the unit.^[13]

The table shows how the margin widens as the unit gets smaller.^[13]

Minor geometric irregularities and changes to finishes may also count as “executive” tolerances, but the provision applies to them only for buildings not under heritage protection.^[13][14] The tolerances are declared by a technician, in the forms for new applications or in a sworn declaration attached to deeds transferring rights. In seismic zones the technician also attests to compliance with the seismic requirements.^[13]

The second provision is regularisation. For partial deviations from a permit or notification, and for some works without a notification, the person responsible or the present owner may apply for a permit or notification after the event, if the work complies with the planning rules in force when the application is made and with the building rules in force when the work was carried out.^[15] The permit may be made conditional on works needed to meet technical safety rules. Where the landscape authorisation was missing, a binding opinion of the authority for the protected area is required.^[15]

Neither provision changes the cadastre, and a cadastral update does not regularise a planning deviation.

What does the deed say about each record?

Both records appear in the deed, in different ways. See also “Due Diligence: What Sinks a Purchase”.

On the cadastral side, a deed transferring a right in an existing building must state, on pain of nullity, the cadastral identification, the reference to the plans filed in the cadastre and the declaration by the holders that the cadastral data and plans match the actual state, which a technician’s attestation can replace.^[16] Before the deed, the notary identifies the cadastral holders and checks them against the property registers.^[16] In October 2025 the Court of Cassation held that this nullity is “formal and textual”: it applies when the declaration or attestation is missing, not when it is inaccurate, unless the inaccuracy is evident even to a non-technician.^[17] A person who makes a false declaration remains liable civilly and, in some cases, criminally.^[18]

On the building side, for buildings begun after 17 March 1985, the deed must state the details of the building permit, or of the permit granted after the event, on the seller’s declaration. Otherwise it is void and cannot be concluded.^[19] For work begun before 1 September 1967, a sworn declaration by the owner may replace the permit details.^[20] The Joint Sections of the Court of Cassation have held that the planning nullity also turns on the presence of a real title, referable to the building, not on whether the building matches it.^[21]

In short, the law requires the two statements to be in the deed. The two statements are made by others: the cadastral one by the holders, or by a technician in their place, the building one on the seller’s declaration. The notary’s own check, under the cadastral rule, is of the cadastral holders against the property registers.^[16] On the cadastral side, the Court of Cassation has said that a lack of conformity does not make the property unsaleable but exposes the parties to assessment by the administration.^[22]