Unauthorised building works: when they become time-barred and what a buyer risks
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Why time does not cancel unauthorised worksWhat «small abuse» meansWhat you risk if you buyHow you check it before making an offerCan it be regularised or not?In practiceFrequently asked questionsSourcesUnauthorised building works (abuso edilizio) are not time-barred like a debt: over the years they do not become legal. Even a small unauthorised work, such as a closed veranda built without permission, remains an unauthorised work until it is regularised or removed. If you buy the property, the problem becomes yours.
Why time does not cancel unauthorised works
An unauthorised work is a structure built without the required building permit (titolo edilizio), or one that differs from how the permit describes it. The permit is the document by which the Comune authorises or acknowledges the works: permesso di costruire, SCIA or CILA, depending on the job. If it is missing, the property is not compliant, and the fact that it is old changes nothing.
Two things must be kept separate. The first is the criminal offence: for the offence there is a statute of limitations, that is, a time beyond which the trial can no longer proceed. The court calculates it case by case, and it is not something you can estimate yourself.
The second is the administrative side, that is, the order to remove the work and the penalties. The passing of years does not make them disappear. That is why those who search for «when does it become time-barred» often stop at the wrong answer. To understand how an unauthorised work is recognised and how it is discovered, read what unauthorised building works are and how they are discovered.
What «small abuse» means
Small to you does not mean small in law. A closed veranda, a mezzanine or a canopy built without a permit are unauthorised works, even if they look like details.
There are, however, differences that the law tolerates. They are called construction tolerances (tolleranze costruttive): small deviations between the design and the actual work. They are not unauthorised works and do not need to be regularised. The general rule is that the measurements must stay within a small percentage of the permit. For smaller units the Salva casa decree set different thresholds, so the detail must be checked case by case. Read construction tolerances: what is not an abuse.
The Salva casa decree of 2024 also changed how some partial discrepancies are regularised. If you want to understand how it affects your case, read the dedicated guide.
What you risk if you buy
In general you are not the one who answers for the offence of whoever built the work. However, the property is yours, and the costs come to you. The concrete risks are these:
- Regularisation (sanatoria): if the unauthorised work can be regularised, you must file the application and pay the technical fees and the sums due.
- Demolition: if the work cannot be regularised, removal is at your expense. The cost can be high, so it must be factored in before you make an offer.
- Sale before a notary: in an ordinary sale the deed must refer to the building permit. Without this reference the deed is void, under article 46 of the Testo unico dell'edilizia (DPR 380/2001).
- Mortgage: the bank may ask for documents on building compliance before granting the loan. Ask it which ones it wants before you sign the preliminary contract.
In judicial auctions the picture changes at two points. The transfer decree (decreto di trasferimento) is not hit by the same nullity as an ordinary sale. However, you have precise deadlines: the application for regularisation must be filed within 120 days of service of the transfer decree. Moreover, in a forced sale there is no warranty for defects (article 2922 of the Civil Code). If you discover the unauthorised work afterwards, you cannot ask the judge for a price reduction for this reason.
The rule on the notarial deed (rogito) is explained in detail here: unauthorised works and sale: can the notary draw up the deed?.
How you check it before making an offer
The appraisal report (perizia) is the most important document. It must say whether there are unauthorised works, how they compare with the permits, and how much it would cost to regularise them. The law asks the appraiser to state the building and planning compliance and the cost of any regularisation (article 173-bis of the implementing provisions of the Code of Civil Procedure).
Do the following:
- Read the section of the appraisal report on building compliance and look for the word «sanatoria» or «difformità».
- Compare the floor plan and the land registry extract (visura catastale) with the actual state: rooms, windows, mezzanines and canopies must match.
- Ask the Comune for the building permits for the property. You can do this with a request for access to records.
- If the appraisal report is vague or says nothing on the subject, do not take compliance for granted.
To understand how to read an appraisal report, section by section, there is a dedicated guide: how to read an auction appraisal report, section by section.
Can it be regularised or not?
An unauthorised work can be regularised when it complies with the planning rules in force both at the time it was built and at the time of the application. This principle is called double conformity: what double conformity means. A closed veranda or a mezzanine may fall under this case, or not. It depends on the Comune's rules and on the zone.
If the unauthorised work cannot be regularised, the route is demolition or removal at your expense. That is why the distinction between the two situations decides the real price of the property. Do not trust generic phrases such as «everything can be sorted out»: ask a technician who reads the building permits for an opinion.
In practice
- Ask the Comune for the building permits for the property before making an offer.
- Compare the floor plan, the land registry extract and the actual state: differences in rooms, windows or mezzanines must be checked.
- In the appraisal report, look for the cost of regularisation or demolition and include it in your offer calculation.
- If you buy at auction, note the date of service of the transfer decree: the 120 days for regularisation run from there.
Frequently asked questions
Is an unauthorised work that is twenty years old still a problem?
Yes. The time that has passed does not make an unauthorised work legal. For the criminal offence the statute of limitations may come into play, but the work remains irregular and the issue stays with the property. The buyer inherits it.
If the Comune has never objected to anything, is the property compliant?
No. The Comune's silence is not a building permit. To know whether the property is compliant you need to look at the documents, not check whether anyone has complained.
Can I buy a property with an unauthorised work?
Yes, if you know the costs and timescales before making an offer. Include the cost of regularisation or demolition in your calculation. At auction, moreover, you cannot ask for a warranty for defects discovered afterwards.
Sources
In the same chapter
- Unauthorised building works (abuso edilizio): what they are and how to spot themUnauthorised building works (abuso edilizio) means building or altering a property without the required permit, or in a way different from what was authorised. Here is how they are discovered and what you risk if you buy.
- Building amnesty: the 1985, 1994 and 2003 lawsAn unfinished building amnesty from 1985, 1994 or 2003 does not make the property safe: here is what to check at the Comune before you buy.
General information, not legal or tax advice: the law and the notice of sale prevail.
