In Italian coastal areas, especially in places like Costa Smeralda and other prime seaside markets, many villas and holiday homes have been adapted over time with extra rooms, closed verandas and “creative” layouts that do not always match what was originally permitted. For a foreign buyer, these changes are often invisible during a viewing, but they can have serious legal consequences ranging from demolition orders to fines and difficulties in obtaining financing or reselling the property.
Unauthorised extensions and closed verandas
One of the most common red flags in coastal villas and holiday homes is the presence of extensions and verandas that were built or closed without the necessary permits. Over the years, many owners have added covered terraces, glass verandas or extra rooms to increase internal space and value, sometimes assuming that a lightweight structure or a glass enclosure is “just furniture” and not real building work.
Italian planning law and case law are clear: closing a balcony or veranda with glass or other materials, or adding a veranda that increases surface or volume, normally constitutes new construction and requires a proper planning title. In protected areas, such as coastal zones with landscape or environmental constraints, these verandas can be treated as non‑sanable building abuses, regardless of how long they have existed, because they create extra volume in a zone where new volume is forbidden.
Due diligence needs to do more than simply note that “there is a veranda.” It compares approved plans and any amnesty documents with the actual state of the property, checking whether each veranda appears on official drawings and has been included in previous permits or condoni. When a veranda is missing from municipal records, that is a clear red flag. The consequences can include orders to demolish and restore, fines and, in some cases, even criminal penalties for serious or repeated violations.
Basements turned into living space
Another recurring pattern is the transformation of seminterrati and cantine into fully habitable space: holiday homes advertised with “extra sleeping area,” “tavern,” or “independent guest unit” that, in practice, are basements or underground floors fitted out as bedrooms, small apartments or B&B units. Often, these spaces lack proper height, natural light, ventilation or safety requirements for legal habitability, and their authorised use in planning documents is storage, garage or technical area rather than residenza.
From a legal point of view, using non‑habitable basements as bedrooms or holiday units is not just a lifestyle choice; it can be seen as a change of use and, in some cases, as a building abuse. The problem becomes acute when owners start renting these spaces to tourists: controls triggered by neighbours, tax authorities or guest checks can reveal that part of the advertised villa or apartment is not legally habitable, jeopardising the entire rental operation and exposing owners to sanctions.
A careful due diligence inspects how basements and lower levels are described in cadastral and planning documents and compares that with actual use. If a property is presented as having four bedrooms but only two appear in the approved plans and the other two are in the basement, this is not a minor discrepancy – it is a signal that the internal layout has changed in ways that may affect the legality of use and the declared surface.
Partially regularised abuses and “half‑amnestied” properties
Some coastal villas and holiday homes have a history of amnesty applications (condono) or sanatoria that were filed but never fully completed, or that covered only part of the irregular works. A seller may present a property as “sanato” because a previous condono application was accepted for certain works, but additional modifications carried out later remain unregularised.
Buying a property with a condono “in itinere” or partially granted means stepping into an administrative process with unknown deadlines and outcomes. Until the municipality issues a final concession in sanatoria, any assurance of regularisation is provisional. In protected coastal zones, recent jurisprudence has also limited the possibility of partial sanatoria where the overall building remains substantially non‑compliant, emphasising that works must be evaluated as a whole rather than as isolated parts.
Due diligence must therefore reconstruct the full history of amnesty requests, verify which works were included, check whether all required fees and charges were actually paid and confirm whether the municipality has issued a final title or left the file pending. When only part of the property is covered by sanatoria and other works remain outside any permit, the buyer must understand that “sanato a metà” is not a technicality but a structural risk: banks may refuse financing, future permits may be blocked and the only way to clean the situation may be demolition or expensive regularisation, if allowed at all.
Hidden inconsistencies that affect validity and value
Beyond visible additions like verandas and basement conversions, due diligence often uncovers less obvious inconsistencies that can affect both the validity of the sale and future value. These include missing or outdated certificates of habitability (agibilità), discrepancies between cadastral records and the actual configuration, and planning non‑conformities where extensions or internal redistributions were never formalised.
Italian law now requires that the parties declare the cadastral conformity of the property at the time of sale, but the responsibility to verify lies with them, not with the notary. If town‑planning non‑conformity is serious and affects essential features of the property, under some conditions it can even impact the validity of the sale agreement, especially if the buyer was not informed and the irregularity makes the property unusable for its intended purpose.
From a buyer’s perspective, these “invisible” red flags rarely appear in marketing material or during a short visit. They emerge only when someone methodically compares drawings, permits, cadastral data and actual state. That is why relying solely on aesthetic impressions or agent assurances is particularly risky in coastal and holiday contexts where informal modifications are common.
Why written due diligence on coastal villas and holiday homes matters
For international buyers, the main value of a legal‑first due diligence on coastal villas and holiday homes is not simply being told “there is an abuse,” but receiving a written explanation of what each red flag means in practice. A well‑structured report will distinguish between small, regularisable irregularities, more serious issues that require negotiation and price adjustment, and non‑sanable abuses that are incompatible with the buyer’s risk appetite.
This written work product becomes essential when decisions are not made by a single individual but by a couple, a family, a bank or a family office. It allows everyone to see, in black and white, where verandas, extensions, basement uses and partial sanatorie stand in relation to current law, what the realistic options are and whether the property still makes sense at the agreed price.
In markets where many holiday homes have been “improved” informally over time, being able to recognise typical red flags—and having them properly analysed before signing a preliminare—is what separates controlled acquisitions from expensive surprises after the notary.