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, generous living area, and south-facing terrace. What no document made obvious was a kitchen extension into utility space completed in 2009 without licensing. HomeOS Fair Price Score flagged the mismatch. Estimated legalisation quote: 34.000EUR.

The buyer renegotiated before CPCV and avoided taking that liability at full price.

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

This guide explains what Simplex 2024 means for buyers in Portugal and how to protect yourself before signature.

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

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

Portugal urban planning law has always, in principle, held property owners responsible for keeping properties compliant with licensing requirements. In practice, enforcement was inconsistent and post-sale liability was often disputed. Sellers argued buyers purchased knowing the condition. Buyers argued unlicensed works were not disclosed. Courts split decisions.

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

The law formalised what was previously contested: the Escritura Publica is the moment of full transfer of legal ownership and all obligations attached to it. From the second you sign, you are owner in every legal sense - including every regulatory non-compliance on the property. If the Camara Municipal discovers unlicensed works, it 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 discovering unpermitted works post-completion had meaningful legal routes: claims for non-disclosure, arguments of material misrepresentation, and court proceedings to apportion liability. Expensive and slow, but still leverage.

After DL 10/2024, statutory clarity makes those post-completion claims significantly harder. The law position is that a diligent buyer verifies regulatory status before purchase - via Licenca de Utilizacao, floor plans, and available building records. If you did not check, the assumption is acceptance as-is.

The practical implication: Every CPCV signed after DL 10/2024 came into force is signed in a legal environment where 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 Publica - the notarised final deed. Not at CPCV. Not at key handover. At the Escritura Publica, before the notario, when ownership legally transfers. Before escritura, seller remains responsible. After escritura, you are.

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

Before the CPCV

You have maximum leverage. No funds committed. You can walk away at no cost. This is when HomeOS verification and any specialist inspection should happen. Discovering unpermitted works here means you can decline or negotiate hard before commitment.

After the CPCV, Before the Escritura

Your deposit is committed - typically 10% of purchase price. You can still withdraw, but lose the deposit. You still have meaningful leverage to renegotiate price or require seller remediation before completion. If HomeOS or your lawyer finds a Simplex 2024 issue at this stage, your options are price renegotiation or rescission if CPCV clauses allow it.

At the Escritura Pública

Once the notario registers the deed, ownership transfers fully. Every unpermitted work becomes your legal responsibility. The Camara Municipal acts against current owner - you. Your solicitor executes the transaction; they do not perform last-minute due diligence for you.

After the Escritura

You own the problem. Options are legalisation (if possible), demolition (if legalisation refused), or ongoing non-compliance with enforcement risk. Claims against seller may exist but are difficult, expensive, and rarely fully successful.

What About the Seller's Obligation to Disclose?

Sellers are legally expected to disclose known material defects. In practice, sellers often claim they were unaware of licensing irregularities because works were historic or informal.

Portuguese litigation can be lengthy and expensive. The most effective protection is to detect issues before signing rather than litigating after completion.

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

An obra sem licenca (unpermitted work) in Portugal is any structural addition, alteration, or extension to a property carried out without the required Licenca de Construcao from the Camara Municipal, or not reflected in the current Licenca de Utilizacao. Under Simplex 2024 (DL 10/2024), all such works become buyer liability at the Escritura Publica.

Not all modifications require a construction license - minor cosmetic works like repainting, replacing floor tiles, or fitting kitchen units are not licensed works. The licensing threshold relates to structural changes, building envelope changes, floor-area/layout changes, and changes affecting registered description.

Here are the 12 most common unpermitted works HomeOS 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 HomeOS'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 CPCV requires comparing three sources: Licenca de Utilizacao from Camara Municipal, Plantas do Imovel in municipal archive, and actual physical state observed in person or via HomeOS document cross-analysis. Discrepancies between any two indicate potential obras sem licenca.

Follow these steps before any CPCV is signed:

Step 1: Obtain the Licença de Utilização

Request current Licenca de Utilizacao from seller or directly from the relevant Camara Municipal. This confirms licensed use and approved configuration at issue date. If seller claims none exists (possible for pre-1951 property), require written explanation and verify independently.

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

Caderneta Predial Urbana from AT contains registered area. Compare against area in Licenca de Utilizacao. Any discrepancy - even a few square metres - signals unregistered modification. If Caderneta area is higher than Licenca, works were added. If both match each other but not the property, modifications are unregistered in both systems.

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

Plantas do Imovel are archived at Camara Municipal and can be requested as certified copies. They show licensed internal layout at build date or last licensed renovation. Comparing plan to actual room-by-room layout reveals modifications not covered by Licenca de Utilizacao.

Step 4: Cross-reference the Ficha Técnica de Habitação

For post-2004 properties, Ficha Tecnica de Habitacao must exist. It records technical specs including areas, materials, and modifications in recent history. Discrepancies versus current state are direct indicators of unlicensed post-construction changes.

Step 5: Run HomeOS Before the CPCV

HomeOS automates steps 1-4 from uploaded documents. The Reality Gap Score from this cross-analysis scores divergence between registered and actual state from 0-10. Score above 4 warrants further investigation; above 6 indicates you should seek physical inspection before proceeding.

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

Legalisation costs in Portugal - obtaining a retrospective Licenca de Construcao for works already built - range from roughly EUR5,000 for minor modifications to EUR250,000+ for major structural additions. Timelines range from 6 months for straightforward files to 3+ years for complex cases. Some works cannot be legalised at all, and Camara Municipal may order demolition at owner expense.

Here is typical legalisation cost by work category:

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 Camara Municipal refuses legalisation - because works violate current zoning, are in restricted areas, or cannot be brought into compliance - it can issue a demolition order. Demolition cost falls entirely on current owner. For a large extension, demolition can range from EUR10,000 to EUR80,000+ besides loss of space itself.

Case Study: How a Belgian Buyer Nearly Paid EUR34,000 for Someone Else extension

A HomeOS user - a Belgian buyer purchasing a three-bedroom apartment in Lisbon Arroios in late 2024 - ran a HomeOS report before CPCV. Reality Gap Score returned 7. The flag: Caderneta Predial Urbana listed 94m2 while Licenca de Utilizacao showed licensed area of 80m2. Fourteen square metres unaccounted for.

The buyer had visited twice. It looked exactly as described: spacious modern kitchen, open plan, no visible issue.

HomeOS document cross-check found the issue in the numbers. Caderneta 94m2 included a utility area absorbed into kitchen during a 2009 renovation. Licenca de Utilizacao had not been updated. The modification was never licensed.

Buyer consulted an architect, who confirmed the situation and estimated legalisation at EUR34,000 including architecture fees, municipal application fees, and remedial works.

What Happened Next

Buyer presented HomeOS report and architect estimate before CPCV. Seller - unaware renovation was unlicensed and having bought in 2019 - accepted EUR28,000 price reduction. Buyer proceeded at lower price with full awareness of issue and resolution cost.

The Alternative

Without HomeOS Reality Gap Score, buyer would have signed CPCV and then Escritura assuming documented price was fair. Under Simplex 2024, the unlicensed 14m2 extension would transfer as legal liability at signature. Discovery likely during later permit, resale, or municipal survey. Post-Escritura options: pay EUR34,000+ to legalise or accept ongoing non-compliance risk.

The cost of checking: A HomeOS Essential report is EUR299. The cost of not checking in this case was EUR34,000.

How Does HomeOS Fair Price Score Detect Simplex 2024 Liability Before You Sign?

HomeOS Fair Price Score, measured on a 0-10 scale, directly detects document divergences indicating potential Simplex 2024 liability. It cross-references Certidao Permanente, Caderneta Predial Urbana, and Licenca de Utilizacao. Area discrepancies, description mismatches, and licensing gaps elevate the score. Above 6 indicates significant divergence requiring further investigation before signing.

Fair Price Score works because Simplex 2024 liability usually leaves a paper trail, specifically inconsistencies across official records describing 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 Simplex 2024 liability waiting to transfer. Reality Gap Score finds them before you sign. After signing, they are yours.

What HomeOS Checks and What It Doesn't

HomeOS Fair Price Score identifies document-level divergences between official records. It does not perform physical inspection. For score above 6, HomeOS recommends physical inspection. InspectOS is an independent specialist inspection company that performs on-site verification of condition and layout against documentation.

-> The Fair Price Score: how HomeOS 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. HomeOS Reality Gap Score Threshold Clause

Some buyers' solicitors are now including clauses tying completion to a HomeOS 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