Αυθαίρετα: the most common trap for foreign buyers in Greece

The apartment looks perfect. The balcony has been glazed and turned into a winter garden, so the living room is ten square metres larger than the listing says. The seller presents this as a benefit. The winter garden does not appear in the paperwork.

That is an αυθαίρετο — part of a building constructed without a permit or in breach of one. In English it usually appears as „unauthorised building works“, and it is the most common reason transactions in Greece collapse at the last moment.

What usually turns up

• Glazed or roofed balconies and terraces
• A garage or storeroom converted into living space
• A room added on the roof terrace
• A basement converted into a flat, with its own entrance
• A pool or outbuilding in the garden without a permit
• An altered internal layout that changes the number of dwelling units

Not all of these carry the same weight. Some are minor deviations that are regularised for a few hundred euros. Others mean that part of the floor area you are paying for does not legally exist — and cannot be registered in your name.

The law is unambiguous

For every property transfer, an engineer issues a certificate (βεβαίωση μηχανικού) confirming that the building has no unauthorised deviations, or that any deviations have been regularised and paid for. Without that certificate the notary cannot execute the deed.

That is a protection for the buyer, but it only works if it happens in time. If the engineer only attends once the deposit has been paid, your negotiating position is considerably weaker — the money is already with the seller.

If the certificate finds a problem

There are exactly two options, and both are legitimate:

1. The seller legalises at their own cost, before the notarial deed. Legalisation involves a declaration, an engineer's drawings and payment of a fee, and takes anywhere from a few weeks to a few months.
2. The cost of legalisation comes off the price, and you take it on after the purchase — with a written estimate from an engineer of what that amounts to.

There is no third option. „Nobody touches that, everyone does it this way“ is not an option, because the transfer simply cannot be completed without the certificate.

What legalisation costs

It depends on the floor area, the zone and the type of deviation. A 12 m² glazed balcony in a residential zone typically falls between one and three thousand euros, including drawings and the fee. A room added on the roof can be considerably more, and in certain cases — in protected zones, along the coastline, or where the deviation exceeds the percentage the law allows — legalisation is not possible at all and the only remedy is demolition.

Which is why the question to put to the engineer is never „are there any problems“, but „what exactly is unauthorised, what does it cost to resolve, and can it be resolved at all“.

How this plays out in practice

The usual scenario is not fraud. The usual scenario is that the seller inherited the apartment from their parents, the balcony was glazed in the eighties, nobody has thought about it for decades, and the seller genuinely does not know it is a problem. A well-intentioned seller, once the engineer points it out, will normally agree either to reduce the price or to legalise.

The problem arises when the buyer finds out after the deposit — at which point the same conversation becomes a negotiation from the weaker side.

What to ask your agent for

Before you pay a deposit, ask for:

• a copy of the building permit and the approved drawings
• the title extract from the land registry (Ktimatologio)
• the energy performance certificate
• a report from an engineer of your choosing — not the seller's

These are standard documents and a serious counterparty has them ready. If they do not, that alone is not a reason to walk away — but it is a reason to have an engineer attend before you sign anything.