In the practice of buying and selling real estate, it can happen that seller and buyer, although aware of the existence of an unauthorized portion or building discrepancies, choose not to declare them in the notarial deed, setting up the sale “as if” that part did not exist.

It is a choice that exposes both parties to very high risks: criminal (for statements made in a public deed), administrative (because the abuse “follows” the property), and civil (especially in the event of litigation over price, guarantees, termination, and returns).

The following is a clear and operational framework for orientation.

1) Building abuse and discrepancies: why they affect buying and selling

“Building abuse” and “nonconformity” do not only mean total construction without a title: they often include expansions, balcony/veranda closures, accessory rooms made or converted, interior alterations with building significance, or work in partial deviation from the title.

The key point is that these irregularities:

• may affect the marketability of the asset (including in relation to mortgages and resale);

• expose them to municipal demolition/restoration orders and other consequences;

• make it extremely dangerous to “fix” the matter with incomplete or reticent statements in the deed.

2) The essential regulatory framework (without unnecessary technicalities)

2.1 The most relevant urban planning and building regulations.

• Art. 46 D.P.R. 380/2001 (Testo Unico Edilizia): regulates zoning mentions in transfer deeds and nullity in case of omission.

• Art. 36-bis D.P.R. 380/2001: conformity assessment for partial non-conformities and specific cases, when the conditions are met.

• Art. 34-ter D.P.R. 380/2001: rules on special cases of interventions performed in partial non-conformity with the title.

• Art. 30 and Art. 40 Presidential Decree 380/2001: provisions on illegal subdivision and on controls/sanctions/recovery and amnesty.

Practical note: “regularization” is neither automatic nor always possible. When it is feasible in the abstract, it must be planned before the deed (or regulated with consistent contract clauses).

2.2 The civil and procedural rules that recur most often in litigation

• Art. 1376 c.c. (translative effect of consent) and art. 2643 c.c. (acts subject to transcription): frame transfer and real estate publicity.

• Art. 1479 Civil Code (buyer’s good faith) and Art. 1154 Civil Code (knowledge of illegitimate provenance): useful for understanding when and how good faith affects protections.

• Art. 2841 c.c., Art. 2665 c.c.: profiles on omissions/inexactitudes in titles or notes, often evoked when documentary and publicity problems arise.

• Art. 186-ter c.p.c. (injunction): may be relevant in procedural strategies for recovery of sums in civil judgments, when the conditions are met.

3) The “urban nullity” of Article 46: what it really means.

Article 46 Presidential Decree 380/2001 requires specific urban planning mentions/declarations in certain deeds. If they are missing, the law provides for nullity.

Beware, however: civil jurisprudence has clarified that this nullity is, in general, a “formal” nullity , typically pegged to the lack of the required mentions, and not automatically to any “substantial” irregularity of the building. This principle was affirmed by Cass. civ. sect. united, no. 8230/2019.

Translated concretely: one should not confuse the issue of the formal validity of the deed with the (very risky) choice to knowingly keep silent about an abusive portion. Even when the deed “holds up” formally, criminal liability, administrative measures and civil law consequences can be triggered.

4) The criminal risk: ideological misrepresentation of a private individual in a public act (Article 483 of the Criminal Code).

4.1 Why “keeping silent knowing” can become a crime

If the parties knowingly omit the existence of unauthorized portions or make untrue zoning declarations in the deed, the crime of ideological forgery committed by a private party in a public deed (Article 483 of the Criminal Code) may be committed.

In the field of real estate transfers, the Criminal Cassation has affirmed the existence of a duty of truth in statements made to the public official, which is also linked to the protection of public interests in matters of land governance: in particular, Criminal Cassation, Sec. V, No. 11628/2012.

The same line of interpretation has been reiterated in several arrests of Section V on the subject of false statements in notarial acts or public acts related to real estate circulation, including Criminal Cass., Sec. V, No. 36694/2008, Criminal Cass., Sec. V, No. 50668/2016, Criminal Cass., Sec. V, No. 5178/2018 and Criminal Cass., Sec. V, No. 11233/2019.

4.2 Seller and buyer: who is liable and how

• Vendor: he is normally the person who makes (directly or indirectly) the most sensitive statements about the urban-building status; therefore, his position is often central in the hypothesis of Article 483 of the Criminal Code (see, among others, Cass. pen., Sec. V, no. 5178/2018).

• Buyer: if he or she consciously participates in the choice to “not bring out” the abuse, there may be an aiding and abetting in the formation of a public act that represents a non-corresponding reality (consistent with the principles recalled by Cass. pen., Sec. V, no. 11628/2012 and subsequent Section V jurisprudence, including Cass. pen., Sec. V, no. 11233/2019).

4.3 The position of the notary

On the criminal side, the Supreme Court has ruled out, as a general rule, an obligation of the notary to verify the correspondence to the truth of the statements made by the parties regarding urban conformity: an issue addressed by Criminal Cass., Sec. V, no. 11628/2012.
This, however, does not mitigate the liability of the parties when the omission or mendacity is conscious.

5) The administrative profile: construction abuse “follows” the property (and affects the current owner)

A recurring misconception is to believe that the municipality can only target the material author of the abuse. In reality, sanctioning and restorative measures (typically the demolition/restoration order) are related to the protection of urban planning and often have a real rationale: they can also be directed at the current owner.

This approach is constant in administrative jurisprudence, and has been clarified particularly authoritatively by the Plenary Meeting of the Council of State: Cons. Stato, Ad. Plen., no. 9/2017 and Cons. Stato, Ad. Plen., no. 16/2023.

Buyer awareness = even weaker position

When the buyer was already aware of the abuse at the time of purchase (and especially if he or she agreed to keep quiet about it), it becomes much more difficult to invoke any protection related to “blameless” reliance.

6) Civil law consequences: why the “between us” agreement does not shelter

Even assuming that seller and buyer were both aware of the discrepancy, the choice not to declare it often produces destabilizing effects in the contractual relationship, because all it takes is for an external element to intervene (municipality, bank, future resale, technical expertise, condominium litigation) to bring out the criticality.

6.1 Price, guarantees and remedies: what happens when the problem explodes

In real estate litigation, zoning and construction irregularities can affect:

• price reduction;

• Termination of the contract in the most serious cases;

• compensation for damages and/or reimbursement of costs (technical, administrative, loss of chance, etc.) when the conditions are met.

In substantive civil jurisprudence, construction/urban irregularities are often treated as factors that impair the usability, value, and marketability of the property, with outcomes that may go so far as to recognize incisive remedies and restitutory obligations: see, for example, Trib. Monza, no. 1266/2024, Venice Trib. no. 2344/2024, Messina Trib. no. 2500/2024 e Trib. Salerno, no. 345/2020.

On the level of the Courts of Appeal, the following are also useful (in terms of approaching remedies and contractual fallout) C. App. Naples, no. 5261/2024 e C. App. Naples, no. 178/2025.

6.2 Good faith and fair dealing: the rule is not “as long as we know”

Good faith (Article 1375 of the Civil Code, in terms of fairness and loyalty) remains an essential parameter in the management of the negotiation and execution of the contract. In this sense it is significant C. App. Rome, no. 4919/2025, which values good faith profiles in the presence of urban planning irregularities and non-transparent conduct.

Even when “both knew,” the affair can escalate: if regularization is not possible, if costs explode, or if the property cannot be financed or resold, a conflict often arises over who should bear the consequences and expenses.

7) What to do, concretely, if an unauthorized portion emerges at the buying and selling stage

If you are a buyer

1. Technical verification (access to records, lawful status, titles, drawings, consistencies).

2. Evaluate sanctionability and timeframe before you bind yourself (or provide suspensive/resolving conditions).

3. Avoid any “solution” based on ongoing silence: this is the most criminally exposed point (Art. 483 of the Criminal Code), as shown by the guidelines of Cass. pen., Sec. V, No. 11628/2012 and subsequent ones, including Cass. pen., Sec. V, No. 5178/2018.

4. If you decide to proceed, include consistent contractual protections (price deposit, clauses on fees and regularization activities, specific guarantees).

If you are a seller

1. If possible, regularize before the sale or set up a transparent and contractually manned sale.

2. Failure to make statements “of convenience”: the risk under Article 483 of the Criminal Code is real (see Cass. pen., Sec. V, no. 11628/2012, n. 50668/2016, n. 11233/2019).

3. Handle the topic of Article 46 T.U. Construction correctly, remembering the framing of the United Sections(Cass. civ., Sec. Unite, no. 8230/2019) but without using it as a “screen” for conscious omissions.

8) Conclusions

In real estate buying and selling, the idea that an unauthorized portion or a building discrepancy can be “handled” simply by keeping it silent in the deed is, in essence, an illusion. The problem does not disappear: it remains embedded in the property and often resurfaces when it is most damaging, such as at the time of a mortgage application, appraisal, resale, municipal inspection, or litigation between the parties. At those times, what seemed like a shortcut becomes a blocking factor, with costs and time tending to rise precisely because the issue was not properly addressed at the outset.

The most sensitive profile is the criminal one. A notarial act is a public deed, and the statements made there, if untrue or if they are constructed in such a way as to represent a different reality, may integrate the ideological falsity of the private individual in a public deed under Article 483 of the Criminal Code. The jurisprudence of the Criminal Cassation has repeatedly referred to the requirement of truthfulness of urban planning statements made to the notary in this matter, with pronouncements that constitute a constant reference: Criminal Cass., Sec. V, No. 11628/2012, Criminal Cass. , Sec. V, No. 5178/2018 and Criminal Cass., Sec. V, No. 11233/2019.

Added to this is an often underestimated fact: at the administrative level, construction abuse tends to “follow” the property and can also be challenged against the current owner, regardless of who physically carried out the work. This approach, repeatedly reiterated by administrative jurisprudence (see Cons. Stato, Ad. Plen., no. 9/2017 and Cons. Stato, Ad. Plen., No. 16/2023), means that the buyer cannot reasonably rely on the fact that “it concerns the seller” or that “it is a problem of the past.” And when the issue resurfaces, it almost inevitably produces civil law repercussions: claims for price reduction, termination, restitution, damages, and litigation over contractual warranties, according to dynamics that merit and appellate jurisprudence frequently addresses (among others: Trib. Monza, no. 1266/2024; Venice Trib. no. 2344/2024; Messina Trib. no. 2500/2024; Trib. Salerno, no. 345/2020; C. App. Naples, no. 5261/2024; C. App. Naples, no. 178/2025; C. App. Rome, no. 4919/2025).

Ultimately, when a discrepancy emerges, the really prudent choice is not to “play it cool,” but to bring it into focus: to figure out whether and how it can be regularized, what the costs and timeframes are, and-if you decide to proceed anyway-to regulate the issue transparently and consistently, with appropriate clauses. This is the only way to reduce the risk of turning a buyout into a source of liability and litigation in later years.