The short answer
Due diligence is the work of comparing who can sell the property, what the records describe, what the municipality has authorized, what physically exists, what obligations come with it, and what you intend to do there. No single document answers all six questions. The practical goal is to identify discrepancies early, put each question to the right professional, and decide what must be resolved before you sign a contrato-promessa de compra e venda (CPCV), the binding purchase-and-sale promise commonly used before completion.
This is not a search for a perfectly tidy file. Older buildings have histories, and an inconsistency can have an innocent explanation. But “everyone says it’s fine” is not evidence. An American buyer should know what is confirmed, what is merely asserted, and what remains for the lawyer, architect, engineer, surveyor or municipality to establish.
Start with the property you think you are buying
Write down the proposition in ordinary language: “A two-bedroom apartment with one private parking space and a storage room,” or “A house with a garden, a separate guest annex and room for a pool.” Include the uses that matter to you: full-time home, rental, renovation, home office, accessibility adaptations, or keeping animals.
That sentence becomes the test for the file. A beautiful finished basement is less valuable to a buyer who needs a third lawful bedroom if its approved use is storage. A courtyard used exclusively by one apartment deserves a different question from a courtyard that the apartment owns. Physical access is not necessarily a registered right of access. Ask early enough that the answers can affect your offer, inspections, contract terms, or decision to walk away.
Which professional answers which question?
| Professional or authority | What to ask them to establish |
|---|---|
| Buyer’s Portuguese lawyer | Seller identity and authority, title and burdens, contract and deposit protections, occupancy, documentary inconsistencies, and the legal consequences of unresolved issues. |
| Real estate agent | Collect the file, identify differences between the listing and the records, coordinate access and questions, and help negotiate a response. The agent does not certify title, licensing, boundaries or structural safety. |
| Architect or qualified engineer | Compare the built property with the approved project and licensing history; assess possible changes and the process for the buyer’s intended work or use. |
| Independent home inspector or engineer | Examine visible condition, systems and defects within the agreed inspection scope. A sound roof does not prove a lawful extension, and an approved plan does not prove a sound roof. |
| Surveyor or cadastral specialist, where needed | Check boundaries, measured areas, access and potential encroachments, especially for rural or mixed property. |
| Lender and appraiser | Decide what the bank will finance and how it values the collateral. A valuation is not a substitute for the buyer’s legal and technical checks. |
| Tax adviser | Model acquisition, ownership, rental and eventual sale consequences for the buyer’s circumstances, including possible US obligations. |
| Municipality, land registry and tax authority | Supply or clarify their respective records and decisions. A question about approved works goes to the municipality; one about a registered charge goes to the land registry. |
Choose professionals who can work on your timetable. A CPCV date agreed before they can obtain and examine the file can turn a manageable question into a contract problem.
The document stack: what it tells you and what it cannot
| Document | Useful for | Does not, by itself, establish |
|---|---|---|
| Certidão Permanente do Registo Predial (current land-registry certificate) | Registered description, ownership entries, charges and pending registration requests. Ask your lawyer to examine the full entries and relevant history. | Whether a converted room, annex or extension has municipal approval; the exact physical boundary on the ground. |
| Caderneta Predial (property tax record) | Tax article, location, description, areas, classification, recorded holder and valor patrimonial tributário (taxable value). | Legal title or municipal authorization for each structure or use described. |
| Use authorization and municipal licensing history, or evidence of the applicable alternative or exemption | The approved use and the administrative path relevant to the building and any later work. The correct evidence depends on its date and history. | That later changes were authorized merely because the original building had approval. |
| Approved architectural plans and related municipal file | What was proposed and approved at particular stages. Compare dated versions with the property you can see. | That everything shown was built as approved, remains unchanged, or is structurally sound. |
| Energy certificate | Recorded energy classification and recommendations within the certificate’s scope; check the identifier and validity with the SCE system. | A building inspection, a promise about actual utility bills, or proof that every alteration is lawful. |
| Ficha Técnica da Habitação, where one exists | Technical information about certain dwellings and their construction or alterations. | A replacement for the current municipal file or proof of every subsequent change. |
| Condominium declaration, minutes, budgets, accounts, insurance and rules | Charges and arrears, decisions on work, disputes, restrictions and management of shared areas. | That a parking place, attic or terrace is privately owned simply because one resident uses it. |
| Seller identity, inheritance, company or power-of-attorney documents, as applicable | Evidence the lawyer needs to identify everyone whose participation is required and the authority of a person signing for another. | Ownership merely because someone advertises the home or holds the keys. |
Two timing details matter. The Portuguese land registry describes its permanent certificate as continuously updated, including pending applications, with a six-month access period. The Tax Authority describes the Caderneta Predial as valid for 12 months. Obtain current records rather than relying on an old PDF saved with the listing. IRN land-registry service; Tax Authority document guidance.
The sale-deed change that buyers should understand
Portugal’s 2024 urban-planning reform removed the requirement to present the use authorization and Ficha Técnica da Habitação at the act transferring ownership of an urban property. A sale proceeding without those documents being exhibited at the deed does not answer whether the property and its alterations comply with applicable rules. The reform also changed some building and use procedures. Ask the lawyer and architect which records, communications, prior authorizations or exemptions apply to this building; do not assume every property should have the same paper called a “licence.” Decree-Law 10/2024.
Compare the same fact across independent records
Create a one-page comparison with columns for listing; registry; tax record; municipal file; on-site observation; and unresolved question. Begin with the address, freguesia, land-registry description number, tax article, apartment fraction and seller names. Then compare.
- Ownership and rights: who is registered, who is selling, whether there is a mortgage, attachment, usufruct, easement, lease or pending filing, and whether inheritance or a representative’s authority requires more evidence.
- Use and configuration: dwelling versus other approved use; number and arrangement of units; later extensions or converted rooms; the actual use of basements, attics and annexes.
- Areas: land area, building footprint, gross construction area, private area and dependent area. These are different measures; write each under its own label and in square meters before doing any square-foot conversion.
- What is included: garage or parking, storage, balcony, terrace, garden and condominium shares; distinguish ownership from exclusive use of common property.
- Land and access: urban, rural or mixed description; road access, wells, septic system, walls, boundaries and any separate tax article or registry description.
Some differences result from dates, definitions or updates made in one system before another. Others matter substantially to financing, valuation, permitted use or the buyer’s plans. The comparison identifies questions; it does not diagnose the legal answer. Ask the relevant professional to explain a difference in writing and say what, if anything, must be corrected.
Worked example: the attractive “third bedroom”
Illustrative scenario; no real property or client file is depicted. An apartment is advertised as a T3 with 120 m² and a parking space. The Caderneta Predial lists 90 m² of private area and 30 m² of dependent area. A converted basement room is furnished as a bedroom. The land-registry entry mentions the fraction and a parking right, but the buyer has not received the approved plans or the condominium title.
| Claim or observation | Status today | Next evidence and verifier |
|---|---|---|
| Apartment includes parking | Unresolved: the nature and identification of the right must be checked. | Lawyer compares registry, condominium title and the actual marked space. |
| Total stated 120 m² | Partially supported: the tax record contains two different area categories, not 120 m² of private living area. | Lawyer and architect compare the marketing description, approved project and measurements. |
| Basement functions as a third bedroom | Observed physically; approved use unconfirmed. Furnishing does not settle habitability or authorization. | Architect obtains and compares the municipal file; lawyer assesses the contract consequence. |
| Buyer intends to rent it as a T3 | Unresolved: both use and rental economics depend on further checks. | Architect and lawyer review the intended use; buyer revises the budget if needed. |
The right answer might be updated documentation, a different description and price, a workable contractual condition, or a decision that the home does not serve the buyer’s needs. It is not to label the space illegal on incomplete evidence; nor is it to accept the listing’s description as proof.
Look beyond the obvious rooms
On a second viewing, compare the property to plans rather than relying only on the first impression. Pay particular attention to enclosed balconies, added bathrooms, attics, basements, garages converted to living space, terraces, annexes, pools and extensions. For a house with land, add walls, wells, septic arrangements, road access, easements, outbuildings and the usable extent of the parcel. A structure appearing on a tax record, satellite image or utility bill does not establish that its present configuration and use were approved.
Ask about the work the buyer hopes to do, too. “We can always add a pool,” “the annex can become a rental,” and “the land is big enough for horses” are proposals, not established rights. Site-specific planning, building, land, condominium and operational rules may all matter. An architect or other qualified specialist should review feasibility with the relevant authority before those plans become a reason to buy.
The physical inspection is a separate track. Moisture, roof condition, electrical installations, drainage, structural movement and the condition of shared building elements affect costs even when the paperwork is in order. Agree on the inspection’s scope and limitations. If access to a roof, basement or concealed system is unavailable, record that limitation rather than treating “not inspected” as “satisfactory.”
For apartments, read the condominium as part of the property
A buyer acquires a home within a building that makes collective decisions. Request the declaration of charges and debts, recent meeting minutes, the current budget and accounts, insurance information and relevant rules. Ask whether major works are proposed or approved, whether there are special assessments or significant arrears elsewhere in the building, and who will bear an approved charge if completion occurs between decision and payment.
Clarify which outdoor space, parking, storage or attic is within the fraction and which is common property with an exclusive-use arrangement. If the apartment has altered windows, a facade, balcony or shared systems, ask whether condominium and municipal approvals were needed and obtained. A tidy apartment interior will not reveal a pending roof assessment or a dispute over a shared terrace.
Ownership, occupants and the path to vacant possession
Ask the lawyer to establish who must sign and whether any mortgage, attachment, usufruct, registered burden, pre-emption process or other right affects completion. If a registered owner has died, the chain of succession and heirs’ authority deserve specific review. A power of attorney should be checked for its validity and scope. Company-owned property raises separate authority questions.
Also establish who is actually occupying the home and on what basis. A lease, another right of occupation, or a seller’s requested period after completion changes what “vacant possession” means. Put any agreed handover, removal of belongings and treatment of keys into the contract. Do not treat a viewing of an apparently empty property as legal confirmation that nobody has a right to occupy it.
Resolve the risk before the promise becomes binding
The CPCV is the point at which uncertainty can acquire an expensive contractual consequence. Before signing or paying, have the buyer’s lawyer review the exact proposal, deposit recipient, conditions, deadlines, identity of the sellers, documentary obligations, financing language and consequences if a condition fails. The AGTP guide to making an offer explains how to present terms; this review asks whether the property and its supporting evidence justify them.
Not every question needs the same solution. The seller may produce a missing record; a professional may establish that a difference is harmless; the parties may agree on a correction before signing; the lawyer may draft a precise condition with a deadline and consequences; or the buyer may revise the price, intended use or decision to proceed. An open-ended assurance that a problem “will be sorted later” is not a substitute for a defined obligation and remedy.
| Observation | Why pause | Request | Lead verifier |
|---|---|---|---|
| Seller’s name differs from the registry | Authority or succession may be unresolved. | Current registry, inheritance or representative documents. | Lawyer |
| Advertised living area includes a basement or annex | Area categories and approved use may differ. | Tax record, plans, municipal file and measurements. | Architect and lawyer |
| Terrace or parking is described as “private” | It may be common property or a use right. | Condominium title, registry and plans. | Lawyer |
| New pool, extension or enclosed balcony | The current construction history needs checking. | Municipal approvals, communications or applicable exemption evidence. | Architect and municipality |
| Large building works discussed by neighbors | A future assessment may change the budget. | Minutes, budget, approved works and charge declaration. | Lawyer and condominium administrator |
| Rural plot looks larger than documents indicate | Boundaries or access may be uncertain. | Registry, tax record, cadastral material and survey. | Surveyor and lawyer |
Before signing a CPCV
- Can the lawyer identify every necessary seller and explain the registered title, burdens and occupancy position?
- Do the property identifiers and each relevant area category make sense across the current registry, tax record, municipal file and listing?
- Have the buyer’s professionals checked any spaces or works on which the purchase depends?
- Has a technical inspection addressed condition, with limitations recorded?
- For an apartment, have the condominium’s charges, decisions, rules and shared areas been examined?
- For land, have access, boundaries and the intended use been checked by the appropriate specialists?
- Is any unresolved matter handled by a precise contractual condition, deadline and consequence approved by the lawyer?
- Are the deposit recipient, payment instructions, financing assumptions and completion timetable independently verified?
Need help organizing the questions? Michael can help you gather a property’s records, compare the listing with what has been supplied, and coordinate the next questions with your independent lawyer and technical specialists. Discuss your property search.
Editorial boundary and official starting points
This article is general educational information, not a title opinion, legal advice, structural report, tax analysis or municipal decision. Requirements depend on the property, its history, the current rules and your intended use. Your retained professionals should inspect the current documents and advise before you commit.
Photography credits
- “Fachada frontal da Casa dos Herdeiros do Sr. José Maria Pereira Gens” — photographer Threeohsix. Source page. License: CC BY-SA 4.0. Cropped for presentation (hero focal crop and social 1200×630 output).
- “Clean facades (54183143897)” — photographer Lars Plougmann. Source page. License: CC BY-SA 2.0. Cropped for presentation.
- “2026-04-12 Quinta do Poço de Côrtes, Alcobaça Municipality 1” — photographer Alexkom000. Source page. License: CC BY 4.0. Cropped for presentation.
Photos are used under their respective licenses for editorial illustration only; inclusion does not imply endorsement by photographers or rights holders.