Afthereta: Checking a Greek Property for Unauthorised Construction Before You Commit

The problem you cannot see on a viewing

Greek has a word for it, afthereta, meaning arbitrary or unauthorised construction. In practice it covers work that was built or changed without a permit, or beyond what the permit allowed. It is not a fringe phenomenon and it is not a marker of a bad property. Decades of building, extending and improving happened faster than the permitting system moved, and a very large share of the Greek housing stock carries something.

What it usually looks like is mundane. A balcony glazed in and counted as a room. A basement or a semi-basement turned into living space. A pergola that became a roof. A storage level converted to a bedroom. A pool, a retaining wall or a boundary that sits a metre from where the plans put it. A staircase to a roof terrace that then acquired a structure. Every one of those changes the built area or the use of the property, and every one of them is a discrepancy between the building on the ground and the building on the file.

The reason it matters to you rather than to the seller is timing. A discrepancy that has never been declared has to be resolved before the property can change hands. If nobody has looked, that discovery happens at the worst possible moment, when your deposit is committed, your mortgage offer has a shelf life and your flights are booked.

What Law 4495/2017 actually classifies

The governing framework is Law 4495/2017, on the control and protection of the built environment. It offers a route to bring older unauthorised work into order, and it sets boundaries around what can be settled at all.

The route covers constructions and changes of use carried out between 30 November 1955 and 28 July 2011, and it sorts them into five categories by seriousness. Categories 1 to 4 run from work that is effectively already lawful or exempt, through small excesses over the permitted dimensions, up to more substantial deviations that can still be settled on payment of a fine. Category 5 is where the serious cases sit, along with work built after the 2011 cut-off, and it is the category you do not want to hear named about a property you are buying.

The window for declaring categories 1 to 4 currently runs to 31 March 2028, following an extension granted earlier in 2026. Treat that date as the position today rather than a fixture. It has been extended more than once, each extension has arrived with a higher fine for later filers, and Greek practice has been that the price of waiting goes up rather than down. Which category a given piece of work falls into, what the fine comes to, and what the current deadline and surcharge actually are on the day you ask, are questions for a Greek civil engineer with the file in front of them. This is not a matter to settle from a website, including this one.

The other thing to understand is what settlement does and does not achieve. Bringing arbitrary work into order under 4495/2017 makes the property transferable and suspends the sanctions attached to it. It is not the same thing as the work having been permitted in the first place, and the technical distinction can matter later if you want to extend, rebuild or insure.

The engineer's certificate is the gate

Greek law makes an engineer's certificate mandatory for any transfer of a property or the creation of a right in rem over it. A civil engineer inspects the property, compares it against the permit and the approved drawings, and certifies the position. Where arbitrary construction exists and has not been settled, the transfer is prohibited outright. The property also cannot be mortgaged, and it cannot be entered into subsidy or support programmes.

Producing that certificate is formally the seller's obligation. It becomes the buyer's problem the moment it is missing, because it is your notary appointment that does not happen, your mortgage that does not draw down, and your deposit that is sitting in someone else's hands while a fine gets calculated. Our guide to selling a Greek property looks at the same certificate from the other side of the table, and the short version there is that most sellers discover the issue at the point of sale rather than at the point of purchase. That is the pattern you are trying not to repeat.

The same certification requirement follows the property through other transfers too, which is worth knowing if the plan is eventually to pass it to children. An estate cannot register an acceptance of inheritance over a property whose building position is unresolved any more than a buyer can complete a purchase over it.

How to find out before you are committed

The sequence that works is short, and the order matters more than the length.

Instruct your own civil engineer, not the seller's. This is the single highest-value decision in the whole process, and the cost is small against the size of the purchase. An engineer acting for you has no interest in the deal closing.

Ask for the permit file and hand it straight to that engineer: the building permit itself, the approved floor plans and elevations, the topographic diagram, and any subsequent permits for alterations. On older properties some of this may only exist in the local planning office archive, and retrieving it takes time you should build into the timetable rather than discover at the end.

Have the engineer measure the property on site against those drawings. That physical comparison is the whole exercise. Photographs, listings and floor areas quoted by an agent are not a substitute, and a property described as, say, 140 square metres in the listing and 95 square metres on the permit is telling you something specific.

Then ask, in writing, whether any previous declaration has been made under Law 4495/2017 or its predecessor Law 4178/2013. If the answer is yes, ask for the declaration, the engineer's technical report that supported it, the fine calculation and proof that the fine was paid in full. A part-paid settlement, or one that covers less than what is actually there, is a live liability that transfers with the property.

Finally, have your lawyer check the Ktimatologio or Hypothikofylakeio entry against what the engineer found, so that the registered description, the permit and the physical building are all telling the same story before you sign anything.

Who pays, and where to settle it

Nothing in the law says the seller pays. The cost and the time of legalisation are negotiable, which is exactly why the negotiation has to happen before you are committed rather than after.

Three positions are common in practice. The seller completes the settlement at their own cost and produces the certificate as a precondition of signing, which is the cleanest outcome and the slowest. The price is reduced by the engineer's estimate of the fine and fees, and you take on the work after completion, which is faster but leaves you carrying the estimate risk. Or an agreed sum is retained from the price until the certificate is in hand, which splits the difference.

Whichever you choose, it belongs in the preliminary agreement, the prosymfono, as an explicit condition with a deadline and a consequence, not as a verbal reassurance from an agent. Our guide to preliminary agreements and mortgage finance covers how those conditions interact with a lender's timetable, which is the part US buyers most often leave out.

What it does to timing, valuation and your mortgage

Timing first. A settlement is not a same-week task. The engineer prepares a file, drawings and a technical report, the fine is calculated, and payment may run in instalments. Add the retrieval of an old permit from a municipal archive and you are realistically talking about months rather than weeks, in a market where sellers and their agents are working to a faster clock.

Valuation next. A bank's valuer assesses what can lawfully be transferred. Square metres that exist physically but not legally tend not to count, so the valuation can come back materially below the price you agreed on the strength of the listing. Because your loan is a percentage of the lower of price and valuation, that gap does not reduce your loan by a little. It lands entirely on your cash deposit.

Financing last, and simplest. Where the arbitrariness has not been settled, the property cannot be mortgaged. There is no version of a strong borrower profile that gets around it. If your offer has an expiry date or a fixed-rate reservation attached, an unresolved building issue can burn it while everyone waits for a municipal office. That risk is worth understanding alongside the mechanics in our guide to non-resident mortgages in Greece.

The specifically American version of this problem

US buyers of Greek property tend to view once, sometimes twice, and then complete remotely through a Greek lawyer holding a power of attorney. That is a sensible way to buy across an ocean, and it removes precisely the check this article is about. You cannot notice a discrepancy between a building and its plans by eye on the day, and you certainly cannot notice it from six thousand miles away.

Two habits close most of the gap. First, make the engineer's inspection an instruction you give directly rather than something you assume the process includes, and ask for the report and photographs to be sent to you, not summarised. Second, write the limits into the power of attorney. A power of attorney that authorises your lawyer to sign the final deed only once the engineer's certificate is in hand converts a trust question into a documentary one, and it costs nothing to draft that way.

The wider point is that a Greek purchase rewards spending money early. An engineer's inspection and an independent lawyer, instructed before the deposit rather than after, are the cheapest part of the transaction and the part that decides whether the rest of it works.

Questions US buyers ask

Continue your Greek property research

• Additional Costs When Buying Property in Greece
• Greek Preliminary Agreements and Mortgage Finance
• Non-Resident Mortgages in Greece: How the Terms Differ