Simplex 2024 — formally Decreto-Lei 10/2024 (DL 10/2024), known as the Simplex Urbanístico — transferred full legal and financial liability for every unpermitted construction on a property to the buyer at the exact moment they sign the Escritura Pública (notarised deed). Before DL 10/2024, liability for obras sem licença (unlicensed works) could be negotiated or contested. After it, the buyer owns the problem completely — regardless of when those works were built, regardless of how many previous owners there have been, regardless of whether the buyer knew. Legalisation costs range from €5,000 to €250,000+. Some works cannot be legalised at all.

A Belgian buyer viewing a Lisbon apartment in late 2024 saw exactly what the listing described: a bright three-bedroom flat with an open-plan kitchen, a generous living area, and a south-facing terrace. The Certidão Permanente (land registry certificate) was clean. The seller had a solicitor. The price was fair. What nobody mentioned — and what no document in the transaction made obvious — was that the kitchen had been extended into a utility space in 2009 without a Licença de Construção (construction license). PropCheck's Fair Price Score flagged the discrepancy between the licensed floor plan and the actual layout. The extension was 14m² of unpermitted construction. Legalisation quote: €34,000.

The buyer renegotiated the price before signing the CPCV — Contrato Promessa Compra e Venda (promissory purchase contract). They saved €34,000 because they checked before signing.

The buyer who signs without checking saves nothing and inherits everything.

This is the only comprehensive English-language guide to Simplex 2024 and what it means for every property buyer in Portugal. If you are buying Portuguese property — anywhere, at any price, new or old — this law applies to your purchase.

What Simplex 2024 Changed for Property Buyers (DL 10/2024)

Simplex 2024 — formally Decreto-Lei 10/2024, published in the Diário da República and in force from early 2024 — is a package of urban planning reforms collectively known as the Simplex Urbanístico. Among its provisions, the most consequential for property buyers is the clarification and hardening of buyer liability for obras sem licença (unpermitted construction works) discovered post-transaction. Under DL 10/2024, the buyer who signs the Escritura Pública inherits full legal responsibility for resolving any unlicensed works — the Câmara Municipal (municipal council) pursues the current owner, not the history of previous owners.

Portugal's urban planning law has always, in principle, held property owners responsible for maintaining their properties in compliance with licensing requirements. In practice, enforcement was inconsistent and liability after a sale was frequently disputed. Sellers argued that buyers purchased knowing the state of the property. Buyers argued that unlicensed works weren't disclosed. Courts split decisions.

DL 10/2024 ended that ambiguity in one direction: the buyer.

The law formalised what was previously contested: the Escritura Pública is the moment of full transfer of legal ownership and all obligations that attach to it. From the second you sign, you are the owner in every legal sense — including ownership of every regulatory non-compliance on the property. The Câmara Municipal, if it discovers unlicensed works, does not pursue the previous owner. It pursues you.

This was not a dramatic departure from legal principle. It was a clarification that removed the wiggle room buyers and sellers previously used to negotiate liability after discovery. The wiggle room is gone.

Key changes that affect your liability

Before DL 10/2024, a buyer who discovered unpermitted works post-completion had meaningful legal routes: claims against the seller for non-disclosure, arguments about material misrepresentation, court proceedings to apportion liability. These were expensive and slow, but they existed as leverage.

After DL 10/2024, the statutory clarity makes those post-completion claims significantly harder to sustain. The law's position is that a diligent buyer verifies the property's regulatory status before purchase — through the Licença de Utilização (occupation license), the floor plans, and any available building records. If you didn't check, the assumption is that you accepted the property as-is.

The practical implication: Every CPCV signed after DL 10/2024 came into force is a CPCV signed in a legal environment where your pre-signing verification is your only protection.

→ Complete guide to property due diligence in Portugal

When Buyer Liability Transfers Under Simplex 2024

Under Simplex 2024 (DL 10/2024), full buyer liability for unpermitted works transfers at the moment of signing the Escritura Pública — the notarised final deed. Not at the CPCV (promissory contract). Not at key handover. At the Escritura Pública, in front of the notário (notary), when ownership legally transfers. Before the escritura, the seller remains legally responsible. After the escritura, you are.

The liability transfer timeline matters because it defines your window of protection:

Before the CPCV

You have maximum leverage. You haven't committed any funds. You can walk away at no cost. This is when PropCheck verification — and any specialist inspection — should happen. Discovering unpermitted works at this stage means you can simply not proceed, or negotiate hard before committing.

After the CPCV, Before the Escritura

You've committed your deposit — typically 10% of the purchase price. You can still pull out, but you forfeit the deposit. You also have meaningful leverage to renegotiate the price or require the seller to resolve specific issues before completion. If PropCheck or your lawyer discovers a Simplex 2024 issue at this stage, you have two options: renegotiate the price to reflect the legalisation cost, or rescind if your CPCV includes appropriate clauses.

At the Escritura Pública

The moment the notário registers the deed, ownership transfers completely. Every unpermitted work on the property is now your legal responsibility. The Câmara Municipal pursues the current owner — that's you. Your solicitor's job is to execute the transaction, not to conduct last-minute due diligence on your behalf.

After the Escritura

You own the problem. Your legal options are: legalise the works (if possible), demolish (if legalisation is refused), or accept ongoing regulatory non-compliance (and face municipal enforcement action that can escalate to forced demolition at your expense). Claims against the seller are possible but difficult, expensive, and rarely fully successful.

What About the Seller's Obligation to Disclose?

Sellers in Portugal are legally required to disclose known material defects. An unpermitted work that a seller actively conceals could theoretically form the basis for a misrepresentation claim post-completion. In practice, sellers frequently argue they were unaware — the works were done by a previous owner, or done informally without the current owner's full understanding of licensing requirements.

Portuguese courts take disclosure obligations seriously, but litigation is slow (3–7 years in many cases), expensive, and uncertain. The most effective protection is not having to litigate at all — which means checking before you sign.

What Counts as an Unpermitted Work in Portugal? The 12 Most Common Examples

An obra sem licença (unpermitted work) in Portugal is any structural addition, alteration, or extension to a property that was carried out without obtaining the required Licença de Construção (construction license) from the Câmara Municipal beforehand, or that is not reflected in the property's current Licença de Utilização (occupation license). Under Simplex 2024 (DL 10/2024), all such works become the buyer's liability at the Escritura Pública.

Not all modifications require a construction license — minor cosmetic works like repainting, replacing floor tiles, or fitting kitchen units are not licensed works. The threshold for licensing requirements relates to structural changes, changes to the building's envelope, changes that alter the floor area or the distribution of spaces, and changes that affect the property's registered description.

Here are the 12 most common unpermitted works PropCheck encounters in Portuguese properties:

1. Balcony and terrace enclosures (varandas fechadas) — Enclosing an open balcony — with glass, aluminium frames, or any permanent structure — changes the property's registered floor area and requires a Licença de Construção. This is one of the most common unlicensed modifications in Portuguese apartments, particularly in urban buildings from the 1970s–1990s.
2. Loft and attic conversions (conversão de sótão) — Converting an attic or roof space into a habitable room — even if accessed only by the property below — requires licensing. The additional habitable area changes the property's registered description and VPT (Valor Patrimonial Tributário — fiscal assessed value).
3. Garage and parking space conversions — Converting a licensed parking space or garage into a living room, studio, or additional bedroom is among the most frequently discovered unpermitted modifications in PropCheck's database. The Licença de Utilização records the garage as a garage. The property functions as a two-bedroom apartment. The discrepancy is immediately visible in a document cross-check.
4. Mezzanines and internal platforms — Installing a mezzanine level in a high-ceilinged space — whether in a residential loft or a commercial conversion — changes the usable floor area and requires licensing.
5. Kitchen and living area extensions (ampliações) — Any structural extension to the main living area that pushes the property's footprint beyond its licensed boundary — even by a few square metres into a terrace, corridor, or common-area space — requires a Licença de Construção.
6. Pool additions (piscinas) — Swimming pools added after the property's original licensing — whether in-ground or above-ground permanent structures — require licensing. This is particularly common in Algarve and rural properties where pools were added informally.
7. Outbuilding and annex construction — Constructing additional buildings on the plot — storage units, guest houses, garden rooms, pool houses — without a Licença de Construção creates unpermitted structures that transfer to the buyer under Simplex 2024.
8. Roof terrace creation (terraços) — Converting a flat roof into an accessible terrace, with access, railings, and surfaces, changes the building's profile and use of space. If not licensed, it's a Simplex 2024 liability.
9. Internal wall removals (demolição de paredes) — Removing load-bearing or structural walls — or walls that define the property's licensed floor plan — without obtaining a Licença de Construção. Even if the structural integrity isn't compromised, the modification may not match the licensed plans.
10. Utility room and laundry conversions — Converting licensed utility spaces into habitable rooms changes the property's registered description and requires licensing.
11. Commercial-to-residential or vice versa — Changing a property's use — from commercial to residential, from residential to tourist accommodation (Alojamento Local) — without the required licensing and change-of-use approval is a form of regulatory non-compliance that Simplex 2024 catches.
12. Covered terraces and pergolas — Permanent covered structures over terraces — glass roofs, solid pergolas, fully enclosed extensions — that weren't part of the original licensed building require construction licensing, regardless of whether they are described as "temporary" or "removable."

How Do I Check Whether a Portuguese Property Has Unpermitted Works Before Signing?

Checking a Portuguese property for unpermitted works before signing the CPCV requires comparing three sources: the Licença de Utilização (occupation license) issued by the Câmara Municipal, the Plantas do Imóvel (architectural floor plans) archived at the municipal council, and the property's physical state as observed in person or through PropCheck's document cross-analysis. Discrepancies between any two of these three sources indicate potential obras sem licença (unpermitted works).

Follow these steps before any CPCV is signed:

Step 1: Obtain the Licença de Utilização

Request the current Licença de Utilização from the seller or directly from the Câmara Municipal where the property is located. This document confirms the licensed use and the approved configuration as of its issue date. If the seller claims the property doesn't have one (valid for pre-1951 properties, less acceptable for newer stock), require a written explanation and verify independently.

Step 2: Compare the Licensed Area Against the Caderneta Predial Urbana

The Caderneta Predial Urbana — the property tax record issued by AT (Autoridade Tributária e Aduaneira) — contains the property's registered area. Compare this against the area in the Licença de Utilização. Any discrepancy — even a few square metres — signals a modification that wasn't registered. If the Caderneta shows a larger area than the Licença, works have been added. If the Caderneta matches the Licença but neither matches the actual property, the modifications aren't registered in either system.

Step 3: Request the Plantas do Imóvel from the Câmara Municipal

The Plantas do Imóvel (architectural floor plans) are archived at the Câmara Municipal. You can request certified copies. These show the licensed internal layout of the property as approved at the time of construction or the last licensed renovation. Comparing these plans against the actual property layout — room by room — reveals any internal modifications not covered by the Licença de Utilização.

Step 4: Cross-reference the Ficha Técnica de Habitação

For properties built after 2004, the Ficha Técnica de Habitação (technical housing file) must exist. It records technical specifications including areas, materials, and any modifications made during the property's recent history. Discrepancies between the Ficha Técnica de Habitação and the current state are direct indicators of unlicensed post-construction modifications.

Step 5: Run PropCheck Before the CPCV

PropCheck automates Steps 1–4 from the documents you upload. The Reality Gap Score — the output of this cross-analysis — scores the divergence between registered and actual state on a 0–10 scale. A score above 4 warrants further investigation. A score above 6 means you should seek a physical inspection before proceeding.

What Does It Cost to Legalise Unpermitted Works in Portugal After Simplex 2024?

Legalisation costs in Portugal — the process of retrospectively obtaining a Licença de Construção (construction license) for works already built — range from approximately €5,000 for minor modifications to €250,000+ for significant structural additions. Timeline ranges from 6 months for straightforward cases to 3+ years for complex situations. Some works cannot be legalised at all, and the Câmara Municipal can order demolition at the owner's expense.

Here is what legalisation typically costs, by category of works:

What Drives Legalisation Costs Up

• • Municipal variation: Lisbon's Câmara Municipal applies stricter standards and higher fees than many inland municipalities. Urban rehabilitation zones (ARU) have specific requirements.
• • Architect and engineer fees: Legalisation requires hiring a licensed architect and often a structural engineer to certify the works as-built.
• • Municipal council fees: Each municipality has its own fee structure for processing legalisation applications.
• • Remedial work: If the unlicensed works don't meet current building regulations, they must be brought into compliance before legalisation is granted — which can mean partial demolition and rebuild.
• • Timeline costs: While legalisation is pending, the works exist in regulatory limbo. This can affect the property's mortgage eligibility and insurance terms.

When Legalisation Is Refused

If the Câmara Municipal refuses legalisation — because the works violate current zoning, because they're in a restricted area, or because they can't be made to comply with building regulations — it can issue a demolition order. The cost of demolition falls entirely on the current owner: you. For a large extension, demolition costs can range from €10,000 to €80,000+, on top of the loss of the space itself.

Case Study: How a Belgian Buyer Nearly Paid €34,000 for Someone Else's Extension

A PropCheck user — a Belgian buyer purchasing a three-bedroom apartment in Lisbon's Arroios neighbourhood in late 2024 — ran a PropCheck report before signing the CPCV. The Reality Gap Score returned a 7. The flag: the Caderneta Predial Urbana listed the property at 94m², but the Licença de Utilização showed a licensed area of 80m². Fourteen square metres unaccounted for.

The buyer had viewed the apartment twice. It looked exactly as described. The kitchen was spacious and modern — a renovation the seller had clearly invested in. The open-plan layout was a selling point. Nothing visible suggested a problem.

PropCheck's document cross-check found it in the numbers. The Caderneta Predial Urbana's 94m² included a utility space that had been absorbed into the kitchen during the seller's 2009 renovation. The Licença de Utilização hadn't been updated. The modification had never been licensed.

The buyer contacted an architect who confirmed the situation and provided a legalisation estimate: €34,000 including architectural fees, municipal application fees, and remedial work to bring the modified space into current building regulation compliance.

What Happened Next

The buyer presented the PropCheck report and the architect's estimate to the seller before signing the CPCV. The seller — who had been unaware that the renovation was unlicensed, having purchased the property themselves in 2019 — accepted a €28,000 reduction in the purchase price to reflect the legalisation liability. The buyer proceeded at the reduced price, fully informed of what they were acquiring and the cost to resolve it.

The Alternative

Without PropCheck's Reality Gap Score, the buyer would have signed the CPCV and subsequently the Escritura Pública on the assumption that the documented price was fair. Under Simplex 2024 (DL 10/2024), the 14m² unlicensed extension would have become their legal liability the moment they signed. Discovery would likely have come during a later renovation permit application, a sale, or a Câmara Municipal survey. At that point — post-Escritura — the options would be: pay €34,000+ to legalise, or accept ongoing non-compliance with enforcement risk.

The cost of checking: A PropCheck Essential report is €299. The cost of not checking in this case was €34,000.

How Does PropCheck's Fair Price Score Detect Simplex 2024 Liability Before You Sign?

PropCheck's Fair Price Score — measured on a 0–10 scale — directly detects the document divergences that indicate potential Simplex 2024 liability. It cross-references the Certidão Permanente (land registry), Caderneta Predial Urbana (tax record), and Licença de Utilização (occupation license) against each other. Area discrepancies, description mismatches, and licensing gaps appear as elevated scores. A score above 6 indicates significant divergence and should trigger further investigation before any contract is signed.

The Fair Price Score works because Simplex 2024 liability almost always leaves a paper trail — specifically, a trail of inconsistencies between different official documents that describe the same property:

• • The Caderneta Predial Urbana records a larger area than the Licença de Utilização → unlicensed space added after the occupation license was issued
• • The Certidão Permanente describes the property as having two floors but the Licença de Utilização covers only one → unlicensed floor conversion
• • The Licença de Utilização was issued in 1975 but the Caderneta Predial records a pool added in the property description → pool without construction license

Each of these patterns is a Simplex 2024 liability waiting to transfer. The Reality Gap Score finds them before you sign. After you sign, they're yours.

What PropCheck Checks and What It Doesn't

PropCheck's Fair Price Score identifies document-level divergences — inconsistencies between what different official records say about the same property. It does not carry out a physical inspection of the building. For a Fair Price Score above 6, PropCheck recommends a physical inspection. InspectOS is a specialist property inspection company — separate from PropCheck — that carries out on-site appointments where a certified inspector physically verifies the property's condition and layout against its documentation.

→ The Fair Price Score: how PropCheck calculates it and what it means

What Should Every CPCV Include to Protect Buyers Under Simplex 2024?

Under Simplex 2024 (DL 10/2024), the CPCV — Contrato Promessa Compra e Venda (promissory purchase contract) — is your last contractual opportunity to create protection before liability transfers at the Escritura Pública. A CPCV that doesn't address unpermitted works leaves you with no recourse after signing. A CPCV with the right clauses gives you the ability to rescind without penalty or require price reduction if Simplex 2024 issues are discovered before completion.

Clauses to Include or Verify in Your CPCV

1. Regulatory Compliance Warranty

The seller warrants that the property is fully compliant with all applicable planning and building regulations, and that the Licença de Utilização accurately reflects the current physical state of the property. A breach of this warranty — a discovered unpermitted work — gives the buyer grounds to rescind or renegotiate.

2. Specific Document Disclosure Requirement

The CPCV should list the documents the seller is providing (Licença de Utilização, Caderneta Predial, Plantas do Imóvel, Ficha Técnica de Habitação where applicable) and warrant that those documents are current and complete. If a document is missing or inaccurate, the buyer has contractual grounds to delay completion.

3. Simplex 2024 Rescission Clause

An explicit clause providing that if any obra sem licença (unpermitted work) is discovered between CPCV signing and the Escritura, the buyer has the right to rescind the CPCV without forfeiting their deposit — or to require the seller to legalise the works before completion or reduce the price by the estimated legalisation cost.

4. PropCheck Reality Gap Score Threshold Clause

Some buyers' solicitors are now including clauses tying completion to a PropCheck Reality Gap Score below a specified threshold (typically below 5 or below 6). If the score exceeds the threshold — or if further investigation reveals a higher score — the buyer has contractual grounds to pause or rescind.

5. Completion Condition on Municipal Records

A clause conditioning the Escritura Pública on confirmation from the Câmara Municipal that there are no active enforcement orders, demolition orders, or obras coercivas (forced municipal works orders) outstanding against the property.

→ The complete guide to buying property in Portugal as a foreigner

Frequently Asked Questions