Illegal Buildings Greece – The Complete Legalisation Guide by Samos Housing

Do you own a property in Greece with an illegal building, an unpermitted extension or an unauthorised structure? You are far from alone — and there is a legal solution. Greece carries a massive legacy of illegal buildings, and the current law gives most property owners a clear pathway to full legalisation. The deadline is 31 March 2028. Samos Housing's licensed engineers manage the entire process on your behalf — from on-site survey to final certificate. If you also want to buy or sell property on Samos, our team covers every step of that process too.

Why Greece Has So Many Illegal Buildings

Building permits became mandatory in Greece in 1955. Cultural and practical adaptation to this requirement happened slowly — particularly in rural areas and on islands like Samos. Throughout the 1960s, 1970s and 1980s, a very large number of homeowners erected homes, extensions and outbuildings without permits. At the time, authorities rarely enforced the rules, and immediate legal consequences did not follow — so the practice spread across the country.

The phenomenon of unfinished buildings in Greece also connects directly to this issue. Property owners who ran out of funds during construction deliberately left buildings unfinished — specifically to avoid local property tax, which applied only to completed structures. As a result, roofless or partially built concrete structures became a familiar feature of the Greek landscape. Many permitted buildings also received illegal extensions over the years — an extra floor, a veranda or a basement that the owner never declared or approved.

By 2010, the scale of the problem forced the government to act. From 2011 onwards, no owner could legally sell, transfer, rent or mortgage any property with an unpermitted building or undeclared illegal extension without first obtaining a certificate of legal compliance from a licensed engineer. If you want to sell a property in Greece, see our property listings and property valuation services — legalisation is often the first step before any sale proceeds.

Three Laws That Changed Illegal Buildings

Since 2010, the Greek government passed three successive laws giving property owners the opportunity to regularise illegal buildings and unauthorised constructions by hiring a licensed engineer, producing plans and paying a calculated fine. Each law extended the scope and deadline of the previous one. The Technical Chamber of Greece (TEE) platform on gov.gr manages all official declarations.

• Law 4014/2011 — the first major amnesty law. Owners declared illegal structures, paid a fine and received a temporary suspension of demolition orders. This law first tied survey topography plans and engineer certifications to all property transactions in Greece.
• Law 4178/2013 — extended the amnesty framework and introduced structured fine calculations based on building age, location and size. Older illegal structures attracted significantly lower fines than recently built ones.
• Law 4495/2017 — the current main framework. This law introduced the five-category classification system for illegal constructions, stricter controls and the requirement for the Electronic Building ID alongside the legalisation certificate. It remains the primary legislation today.
• Law 5106/2024 — the most recent update. It introduced a new national electronic registry of illegal constructions, instalment payment options for fines, reductions for low-income owners and disabled persons, and stronger environmental controls. The Greek Ministry of Environment and Energy oversees all related enforcement and policy.

The 31 March 2028 deadline

This is the most urgent issue for any Greek property owner with an illegal building or unpermitted extension. The confirmed deadline for legalising unauthorised constructions in Categories 1–4 is 31 March 2028. A 40% fine surcharge already applies to all submissions from October 2024 onwards. Every month you wait, your total cost increases — the fine does not drop as the deadline approaches.

Category 5 — which covers large-scale illegal buildings and structures with serious planning violations — has been frozen since autumn 2020. This affects thousands of private properties across Greece, but also public buildings including schools, municipal offices and hospitals built without permits. Millions of properties remain affected and the government faces significant pressure to resolve Category 5 before the current deadline expires.

One rule does not change: only buildings erected before July 2011 qualify for legalisation under current Greek law. Any unauthorised construction built after that date faces demolition — authorities cannot regularise it. If you own a property with a pre-July 2011 illegal building, acting before 31 March 2028 is essential. Once the deadline passes, affected properties cannot be sold, transferred or mortgaged.

An unfinished unauthorised concrete structure — a common sight across Greece since the 1970s. Source: To Vima

Five Categories of Illegal Buildings

Under Law 4495/2017, the Greek government classifies all illegal and unauthorised constructions into five categories based on the severity of the violation. This classification directly determines the fine amount and whether legalisation is possible at all:

• Category 1 — Minor violations such as small technical deviations from the approved permit. These attract the lowest fines and present the most straightforward path to legalisation.
• Category 2 — Small excess construction — for example a house with a slightly larger footprint than approved, or a minor illegal extension. Engineers calculate fines per square metre of illegal area.
• Category 3 — Medium-scale violations, including significant illegal extensions, undeclared floors or major changes of use. Fines are higher and the engineering process more detailed.
• Category 4 — Older illegal structures built before 1983. These attract significantly reduced fines because of their age. Many traditional stone houses on Samos Island fall into this category — making them some of the most cost-effective legalisation cases on the island.
• Category 5 — Large-scale illegal buildings or structures with very serious planning violations. Currently frozen since 2020 — owners cannot legalise these until new legislation passes. For advice on new construction and building permits on Samos, see our dedicated engineering page.

How Greece Calculates Illegal Buildings Fines

The fine for legalising an illegal building in Greece is not a flat amount — a licensed engineer calculates it individually for each property using a standardised government formula. These are the key factors that determine the fine:

• Size of the illegal area — the engineer calculates the fine per square metre of unpermitted construction.
• Year of construction — the older the illegal structure, the lower the fine. Buildings erected before 1983 attract the most significant reductions under Category 4.
• Location and tax zone value — properties in high-value zones such as coastal areas and tourist locations attract higher fines than rural or remote properties.
• Type of use — the government treats residential use more favourably than commercial, industrial or tourist use.
• Category classification — the higher the category, the higher the fine multiplier the engineer applies.
• 40% surcharge from October 2024 — applies to all new submissions until 31 March 2028. Submitting sooner reduces your total cost burden — the surcharge does not disappear as the deadline approaches.

Under Law 5106/2024, owners pay fines in a single payment or in monthly instalments. Reduced fines apply to low-income owners and people with disabilities. Contact us to get a quote for your specific property.

How We Legalise Illegal Buildings Greece – Step by Step

Samos Housing handles the complete legalisation of illegal and unpermitted buildings in Greece from start to finish. Our licensed civil engineers manage every step — you do not deal with the Technical Chamber of Greece, the municipality or any government platform directly. All submissions go through the official TEE arbitrary buildings platform on gov.gr.

• Step 1 – On-site assessment: Our engineers visit the property and review all existing documents — deeds, building permits, old plans and ownership history. We identify every illegal element, determine the applicable category and calculate the exact fine. This is a professional engineering service — not a preliminary consultation.
• Step 2 – Survey and measurement: Our engineers measure the entire property using GPS equipment and where needed LIDAR 3D building mapping — producing accurate as-built drawings of the structure exactly as it stands today.
• Step 3 – Fine calculation: We calculate the exact fine using the official government formula, applying all available reductions based on age, location and size.
• Step 4 – Document preparation: We prepare all required plans, technical reports and declarations for submission to the Technical Chamber of Greece (TEE).
• Step 5 – Submission and payment: We submit the complete file on your behalf. You pay the fine in full or in instalments. We manage all follow-up communication with the authorities.
• Step 6 – Certificate of legalisation: Once you pay the fine and the authorities accept the file, you receive the official legalisation certificate. Your property is then free to be sold, transferred or mortgaged.
• Step 7 – Electronic Building ID: After legalisation, we produce the mandatory Electronic Building ID (Ταυτότητα Κτιρίου) — required for any property sale in Greece from April 2022. We also handle Greek Cadastre registration if your property does not yet appear on the national register.

Illegal Buildings on Samos Island

Samos Island carries a particularly high concentration of properties with illegal buildings. The rapid development of the island in the 1970s and 1980s — combined with limited planning enforcement at the time — produced a very large number of homes, holiday cottages and agricultural buildings erected without permits or with significant illegal extensions. Many traditional stone farmhouses in mountain villages predate the 1955 permit requirement entirely, placing them in Category 4 — making them among the least expensive cases to legalise in all of Greece.

A significant number of properties on Samos also sit partially within forest zones or stream buffers — areas where construction was never legally permitted. These cases require special handling and in some instances cannot achieve full legalisation. Samos Housing knows every zone, every village boundary and every local regulation on the island. We give you the most accurate picture of what is and is not achievable for your specific property before you commit to any costs. If you want to browse available properties on Samos, our listings team flags all legal compliance issues upfront.

Can You Sell a Property With Illegal Buildings in Greece?

No — not without a certificate of legal compliance. Since 2011, Greek law blocks the sale, transfer, donation or mortgaging of any property with undeclared illegal structures. Any notary in Greece requires one of the following before signing a sale contract:

• A certificate of legalisation — confirming that all illegal elements have been formally regularised and fines paid.
• An engineer's certificate of legal status — confirming that the property carries no illegal structures whatsoever.
• An Electronic Building ID — mandatory for all property sales in Greece from April 2022. See our full guide on the Electronic Building ID Greece.

If you are buying a property in Greece, commissioning an independent pre-purchase building inspection before signing anything protects you from a very expensive post-purchase surprise. Our engineers identify all illegal structures, quantify the legalisation cost and confirm whether the property achieves full regularisation before the 31 March 2028 deadline. After legalisation, our certified property valuers produce a formal valuation for mortgage, sale or inheritance purposes.

Services & Fees

Frequently Asked Questions – Illegal Buildings Greece

Can all illegal buildings in Greece be legalised?

No. Only buildings erected before July 2011 qualify for legalisation under current Greek law. Buildings inside protected areas such as forest zones, archaeological sites or flood plains face additional restrictions and in many cases cannot achieve full regularisation. Our engineers assess your specific property and give you a clear answer before you incur any costs.

What is the deadline for illegal buildings Greece legalisation?

The confirmed deadline for Categories 1–4 is 31 March 2028. A 40% fine surcharge applies to all submissions from October 2024 onwards. Acting sooner costs less — the surcharge does not decrease as the deadline approaches.

What happens if I miss the 31 March 2028 deadline?

Properties with unlegalised illegal buildings that miss the 31 March 2028 deadline face a complete block on sale, transfer, donation and mortgage. Authorities also gain the power to issue demolition orders. Acting before the deadline directly protects your financial and legal position.

How does Greece calculate fines for illegal buildings?

A licensed engineer calculates fines per square metre of illegal construction using the official formula under Law 4495/2017. Key factors include the size of the illegal area, year of construction (older buildings attract lower fines), location and tax zone value, type of use and category classification. A 40% surcharge applies to all submissions from October 2024 until 31 March 2028. Under Law 5106/2024, owners pay in monthly instalments.

Can I sell a property with illegal buildings in Greece?

No. Since 2011, Greek law blocks the sale, transfer, donation or mortgaging of any property with undeclared illegal structures. A notary requires either a certificate of legalisation, an engineer's certificate of legal status, or a valid Electronic Building ID before signing any sale contract.

How long does legalising an illegal building in Greece take?

For straightforward Categories 1–3, the process typically runs 4–8 weeks from initial site visit to final certificate, provided all documents are available. More complex cases with missing permits or Category 4 age verification take longer. We confirm a realistic timeline at the assessment stage.

Do I need a new survey plan to legalise an illegal building in Greece?

Yes, in most cases. A certified survey topography plan with EGSA 87 GPS coordinates is a mandatory submission document for the Technical Chamber of Greece (TEE). If your existing plan predates 2012 or lacks GPS coordinates, we produce a new certified plan as part of the legalisation service.

Is legalisation different from a new building permit in Greece?

Yes — completely different processes. Legalisation regularises a structure that already stands without a permit. A building permit covers new construction or an approved extension. In some cases, after legalisation completes, you can then apply for a permit to extend or renovate the building further.

Legalise Your Illegal Building in Greece Before 31 March 2028

The window to legalise illegal buildings in Greece closes on 31 March 2028. Whether you are a Greek property owner, an expat, a foreign buyer or an investor, every month you wait adds cost and risk. Samos Housing's licensed engineers live and work permanently on Samos Island and cover all of Greece — bringing you local expertise, full English-language support and a single point of contact for the entire process. Once legalisation completes, our estate agents list your property immediately if you want to sell.

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