Planimetria catastale difforme: what to do before the rogito

The kitchen wall came down in 2003. The drawing at the land registry still shows it. Between the two stands a notary who, since 2010, is not allowed to sign.

A planimetria catastale is the technical drawing, usually at 1:200, of a unit registered in Italy's Catasto. Decree-law 78/2010 requires every deed transferring a building to state that the cadastral data and the plan match the actual state of the property, on pain of nullity. An owner can download the plan free of charge, and a mismatch is fixed by an authorised technician before the rogito, not after.

Why does the plan matter at the deed?

Article 19, paragraph 14 of decree-law 78/2010, published by the Agenzia delle Entrate, inserted paragraph 1-bis into article 29 of law 52/1985. Deeds transferring, creating or dissolving real rights over existing urban buildings must contain, on pain of nullity, the cadastral identification of the unit, the reference to the filed plan, and the parties' declaration, which a technician may replace with an attestation, that the cadastral data and the plan conform to the current state of the property. The notary checks the declaration against the register before signing.

That is cadastral conformity, a matter of the fiscal register. Building conformity is a separate test. Article 46 of the consolidated building code, DPR 380/2001, makes deeds on buildings whose construction began after 17 March 1985 null unless the seller declares the details of the building permit or the permit in sanatoria. A plan that matches the flat does not prove the flat matches its permits, and a permit does not prove the plan is current.

Where do you get the plan, and what does it cost?

The Agenzia delle Entrate describes the planimetria as the technical drawing, normally at 1:200 scale, of a unit registered in the Catasto, and reserves access to holders of rights over the property, their delegates and those otherwise entitled. Through its consultazione personale service the holder of a real right can download current and historical visure, the plans and the mortgage inspections of their own properties free of charge and exempt from cadastral taxes, after logging in with SPID, the electronic identity card or the national services card.

The buyer therefore cannot pull the plan alone; the seller can, in minutes, at no cost. A seller who cannot produce it before the preliminary contract is asking you to take the declaration on trust.

How much difference is a difference?

The building code answers in percentages. Article 34-bis of DPR 380/2001, in the text in force since 28 July 2024 after the so called Salva Casa reform, treats a departure from the height, distances, volume, covered area or any other parameter of the unit as no building violation when it stays within 2 percent of the measures in the permit. For works completed by 24 May 2024 the tolerance rises as the unit shrinks: 2 percent above 500 square metres of usable floor area, 3 percent between 300 and 500, 4 percent between 100 and 300, 5 percent below 100 and 6 percent below 60. Paragraph 2 adds executive tolerances for minor geometric irregularities, changes to finishes and the different placement of installations and internal works, provided they breach no planning rule and do not compromise the building's fitness for use.

Construction tolerance for works completed by 24 May 2024, by usable floor area of the unit

Usable floor area	Tolerance (%)
Over 500 m²		+2%
300 to 500 m²		+3%
100 to 300 m²		+4%
Under 100 m²		+5%
Under 60 m²		+6%

Paragraph 3 of the same article closes the loop with the deed: tolerances from earlier works are declared by the technician in the attestation of the property's legitimate state, attached to deeds that transfer real rights. A removed wall is not a tolerance; it is a variation that needs a new plan.

Who fixes a mismatch, and when?

The seller, through an authorised technician, before the deed. The cadastral update is filed with the Agenzia delle Entrate through the Docfa procedure, which the agency's Docfa pages reserve to authorised technicians engaged by the holders of rights, and a new plan replaces the old one in the register. Where the work behind the mismatch was never permitted, the cadastral filing does not cure article 46; that requires the building permit route, and the technician's attestation under article 34-bis has to say so.

The rest of the cadastral file, the visura and the atto di provenienza, is decoded in our guide to the visura catastale, and the charges a buyer can inherit from the seller are covered in our guide to condominium arrears.

Ask the seller for the plan from their own free consultation before the preliminary contract, and walk the flat with it in hand. AiMYNDi reads the plan and the visura together and flags the rooms that do not match.