What Is an Alvará, and Why Should You Never Hire a Contractor Without One?
By Pascal Niggli · Co-founder of remodel · Last updated July 2026
A construction licence (alvará de construção) is a mandatory credential issued by IMPIC that authorises a Portuguese contractor to perform specific categories of building work. Contractors without a valid alvará operate outside the law, and the property owner bears direct liability for structural defects, workplace accidents, or permit violations that result from unlicensed work. Foreign owners face a compounded version of this risk: they cannot read IMPIC records in Portuguese, cannot verify licence categories against their project's scope, and are often thousands of kilometres away when work begins. remodel verifies every contractor's alvará against live IMPIC records before any project referral, matching licence categories to the specific trades a renovation requires.
20–40%
Quote markup, foreign owners
Lei 41/2015
Governing construction law
11+
Subcategorias, licence classes
3
Vetted quotes per project
What's in this guide
An alvará de construção is divided into numbered subcategorias that define which trades a contractor can legally perform
IMPIC maintains a public register of licensed contractors, searchable online at impic.pt
Unlicensed renovation work voids most insurance claims and leaves the owner liable for workplace injuries
Foreign owners are typically quoted 20–40% above local rates, and unlicensed operators account for a disproportionate share of those inflated quotes
remodel cross-references each contractor’s alvará categories against the specific trades your project requires
The Alvará Gap: Why Foreign Owners Are Most Exposed
Many Portuguese contractors operate without a valid alvará de construção, and foreign property owners are the least equipped to detect the gap.
The problem is structural. A Portuguese homeowner can phone IMPIC, read the register, ask neighbours for references, and visit a contractor's previous sites within the same week. A foreign owner renovating a property in Cascais, Lisboa, or the Algarve from London, Amsterdam, or New York cannot do any of that. They rely on recommendations from estate agents (who are not construction professionals), Google results (which favour marketing budgets over credentials), or word of mouth from other expats (which spreads both good and bad contractors with equal enthusiasm).
AtençãoSome contractors will show a document that expired years ago. Others will show a licence for subcategoria 1 (minor works) while quoting a full structural renovation that requires subcategoria 5 or higher. Foreign owners have no baseline to detect this.
This information asymmetry is profitable for unlicensed operators. Foreign owners do not know what an alvará looks like, which categories their project requires, or where to check one. The result: foreign owners are quoted 20–40% above local market rates, and a significant share of those inflated quotes come from contractors who lack the credentials to perform the work legally.
What Does a Construction Licence (Alvará) Cover?
An alvará de construção is divided into numbered subcategorias that authorise a contractor to perform specific types and scales of building work, from minor finishes to large civil engineering projects.
Base LegalUnder Lei n.º 41/2015, the law governing access to the construction sector, IMPIC classifies construction work into categories based on complexity, risk, and trade specialisation. Each alvará lists which subcategorias the contractor is licensed for and the maximum financial value of projects they can take on within each category.
Subcategoria
Portuguese name
Scope
1
Edifícios de construção tradicional
Traditional building construction, including structural work on residential properties
2
Edifícios com estrutura metálica
Steel-framed construction
4
Instalações eléctricas
Electrical installations
5
Instalações mecânicas
Mechanical installations, including plumbing and HVAC
7
Reabilitação de edifícios
Building rehabilitation, the category most relevant to renovation of older Portuguese properties
9
Carpintarias
Carpentry work
11
Acabamentos
Finishing works, including tiling, painting, plastering, and azulejo installation
A contractor licensed for subcategoria 11 (finishing works) cannot legally perform subcategoria 1 (structural construction) or subcategoria 4 (electrical installations). If a renovation involves knocking down walls, rewiring, and replumbing, the contractor needs multiple subcategorias on their alvará, or the project needs multiple licensed contractors.
Classe limitsEach subcategoria also carries a class (classe), ranging from 1 to 9, that caps the maximum project value. A classe 1 contractor in subcategoria 7 can take on rehabilitation projects up to approximately €166,000. A contractor taking on a €400,000 full renovation of a heritage building in Sintra on a classe 1 licence is operating outside their authorisation.
How Do You Verify a Contractor's Alvará?
IMPIC maintains a public database of all licensed contractors, searchable by company name, NIF, or alvará number, though the interface is in Portuguese only.
1.Ask the contractor for their alvará number and a copy of the licence document
2.Go to the IMPIC website and navigate to "Alvarás de empreiteiro de obras particulares"
3.Enter the alvará number or the contractor’s company NIF
4.Check three things: the licence is active and not expired, the subcategorias match the trades your project requires, and the classe for each relevant subcategoria covers your project’s estimated value
The process takes about ten minutes if you read Portuguese. If you do not, you are navigating a government database with no English interface, interpreting legal classifications in a language you may not speak, and making a high-stakes decision about a contractor you may never meet in person.
AtençãoSome contractors will provide a photocopy of someone else's alvará. Others will produce a valid licence for a different company within their group. Without reading the original IMPIC record against the contractor's ficha de empresa (company registration), you cannot confirm the licence belongs to the entity you are contracting with.
What Happens If You Hire a Contractor Without One?
Hiring an unlicensed contractor in Portugal transfers legal and financial liability for construction defects, workplace injuries, and permit violations to the property owner.
⚠ Insurance voidance
Most property and construction-specific policies (seguro de obra) require that all contractors hold valid IMPIC credentials. If an unlicensed contractor causes water damage, structural failure, or fire, the insurer can reject the claim.
⚠ Workplace injury liability
Under Portuguese labour law, if an unlicensed worker is injured on your property, the owner can be held co-responsible. Licensed contractors carry mandatory workers’ compensation insurance (seguro de acidentes de trabalho).
⚠ Permit problems
Structural renovations require câmara municipal approval. If the municipality discovers unlicensed work, the permit can be revoked, and in some cases the câmara can order demolition at the owner’s expense.
⚠ Resale complications
Buyers and their lawyers check whether renovation work was performed under valid permits by licensed contractors. Undocumented work flags during due diligence and can reduce the property’s value.
€80k–€120k
Total exposure from a €50,000 renovation performed by an unlicensed contractor that results in a structural defect, including remediation, legal fees, and lost resale value.
Worried about your contractor's credentials?
remodel personally matches your project with a contractor whose alvará subcategorias match your renovation scope. Every licence is checked against live IMPIC records before referral.
How remodel Verifies Contractors Against IMPIC Records
Every contractor on remodel is vetted and verified. Where the work requires an alvará de construção, we check it against live IMPIC records and match the subcategorias to the specific trades they are referred for.
1
Credential check
remodel confirms the contractor's alvará number against the IMPIC public register, verifying the licence is active, the subcategorias cover the trades claimed, and the classe is sufficient for the project values targeted.
2
Scope matching
When a project is submitted, remodel matches the required trades (structural, electrical, plumbing, finishing) against the subcategorias on each potential contractor’s alvará. A finishing-only contractor is never referred for structural work.
3
Insurance verification
remodel confirms current liability insurance (seguro de responsabilidade civil) and workers’ compensation insurance (seguro de acidentes de trabalho), checked at the point of referral, not once a year.
NotaThis removes the verification burden from the property owner. You do not need to read IMPIC records in Portuguese, interpret subcategorias against your scope, or trust a photocopy. remodel personally matches your project with a pre-vetted contractor whose credentials match your project's specific requirements.
Frequently Asked Questions
No. An expired alvará means the contractor is unlicensed. Some contractors apply for renewal and continue working during the processing period, but this is a legal grey area. remodel does not refer contractors whose alvarás are in renewal limbo, the licence must be active on the IMPIC register at the time of referral.
It depends on the scope. A sole trader performing minor maintenance or cosmetic work (painting, small repairs) may operate under a different regime defined in Lei n.º 41/2015. Any construction work involving structural changes, electrical, plumbing, or mechanical systems requires an alvará. If your project involves permits from the câmara municipal, the contractor performing the work must be licensed.
No. An AMI licence (issued by IMPIC under a different regime) authorises real estate mediation, meaning buying, selling, and renting property. An alvará de construção authorises construction work. They are separate credentials for separate professions.
The IMPIC database is in Portuguese only. You can use browser translation tools to navigate it, but interpreting subcategorias, classes, and licence conditions requires construction-specific vocabulary. remodel performs this verification on your behalf and provides an English-language summary of each contractor’s credentials.
Conclusion
An alvará de construção is not a formality. It is the legal document that determines whether a contractor is authorised to perform the specific work a renovation requires, whether their insurance is valid, and whether the owner is protected if something goes wrong. For foreign property owners renovating in Portugal, verifying an alvará is the single most important step before signing a contract, and the one most frequently skipped.
Check licensing and insurance before you hire
remodel personally matches your project with a pre-vetted contractor and benchmarks the quote. Every alvará is verified against live IMPIC records, with staged payments tied to independent milestone inspections.
Pascal is the co-founder of remodel. Originally from Switzerland, he has lived in Portugal for several years and has first-hand experience with the permit, VAT, and contractor issues property owners run into. He built remodel to be the resource he wished existed when he started.
This article is for informational purposes and does not constitute legal advice. Regulatory references are based on Lei n.º 41/2015 and current IMPIC guidelines. Consult a qualified legal professional for advice specific to your situation. Last updated: July 2026.
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