How to read a Portuguese energy certificate
The energy certificate says how the property performs and what improving it would cost. It is required to sell, it lasts ten years, and it ends with a costed schedule of works that almost nobody reads. Below is an illustrative model, field by field.
The energy certificate rates the property from A+ to F and lists improvement measures with estimated costs. It is required to sell or let, and it is the one document of the three that nobody reads to the end — which is a pity, because the improvement-measures page is a costed schedule of works, prepared by a technician and handed free to whoever is negotiating. This model describes the same fração «F» of artigo U-00000 as the caderneta predial and the certidão permanente, and is deliberately close to the end of its validity.
How to use this page
Tap a field on the model to jump to its explanation; the full explanation of every field is also written out below, in order, and reads straight through as ordinary text. Fields marked with a gold dot are the ones where problems most often turn up.
The field names are kept in Portuguese because that is how they appear on the document — each one is glossed in English below it.
Certificado Energético — Sistema de Certificação Energética dos Edifícios
What each field means
Número do certificado
SCE000000000 (ilustrativo) · Emitido através do Portal SCE (ADENE)
- What it is
- The certificate's registration number on the Portal SCE, the platform run by ADENE. It is what lets you confirm the certificate exists, which property it covers and whether it is still valid — the sheet itself proves nothing.
- What is ordinary
- Every certificate issued carries a number and is registered. A PDF with no number, or carrying a watermark declaring it invalid, is not a certificate — article 23.º n.º 4 of Decreto-Lei n.º 101-D/2020 says expressly that those are invalid.
- What stops or delays a purchase
- The number has to correspond to this property and this fraction, not another one in the same building. Confirm it at source, not on the sheet you were handed. This needs verifying before you commit.
Data de emissão e validade
Emitido em 23-03-2017 · Válido até 22-03-2027
- What it is
- The period is fixed by article 23.º n.º 1 of Decreto-Lei n.º 101-D/2020: ten years for an ordinary energy certificate, ten for a pre-certificate, eight for large commercial buildings, and one year for shell buildings. Once it runs out, article 23.º n.º 4 b) makes the certificate invalid — not "out of date", invalid.
- What is ordinary
- Ten years is a long time, and certificates eight or nine years old turn up constantly on properties for sale — this model is deliberately one of them. Article 23.º n.º 3 adds a detail that catches people out: a certificate can be updated while it is live, but updating it does not extend the period — the clock still runs from the original issue.
- What stops or delays a purchase
- This model expires on 22-03-2027, deliberately close to the end, because that is how the problem turns up in practice. A certificate that runs out before the deed forces a new one to be issued, with an expert, a cost and a lead time — and the new certificate may return a different class from this one. Who pays for it is a matter of negotiation and is not settled by law. This needs verifying before you commit.
Perito qualificado
ANA EXEMPLO MODELO · PQ00000 (ilustrativo)
- What it is
- The technician who produced the certificate. Article 2.º s) of Decreto-Lei n.º 101-D/2020 defines the perito qualificado as "the technician holding a professional title to carry out energy certification, under Lei n.º 58/2013". It is a regulated qualification, with its own number, and it is checkable.
- What is ordinary
- The expert is engaged and paid by the seller. That is normal and not improper: somebody has to commission the certificate, and the law requires the seller to hold one. But it means the survey was done for the seller, not for you — and on a certificate this old, for a seller who may no longer even be the current one.
- What stops or delays a purchase
- The expert visited once and recorded what they were shown and told. They did not inspect for defects, did not open walls and did not check whether any works were licensed. Treating the certificate as a condition survey is the mistake it invites. This needs verifying before you commit.
Classe energética
C (escala A+ a F)
- What it is
- The letter summarises the property's modelled energy performance, from A+ (best) to F. It is calculated from the building's characteristics — envelope, glazing, systems — applied to a standardised pattern of use. It is not your consumption, nor the previous owner's.
- What is ordinary
- This model carries a C, which is the most instructive class of the eight: much of the Portuguese housing stock built before 2006 sits between C and E, and a C on a 2000s fraction with double glazing, frames without a thermal break and uninsulated walls is exactly what you would expect. It is neither bad enough to alarm nor good enough to ignore — it is the band where the improvement measures have a real payback and are worth reading. The letter also moves when equipment is replaced, so an old certificate may no longer describe the property you are viewing.
- What stops or delays a purchase
- The letter is a model, not a measurement: it does not tell you what your electricity will cost, nor whether the flat is cold in January. The per-use indicators, the description of the envelope and a winter viewing are what answer that. And it is a ratio, not a consumption — the scale below explains what against. This needs verifying before you commit.
Indicadores de necessidades energéticas
Aquecimento 78,4 kWh/m².ano · Arrefecimento 9,1 kWh/m².ano · Águas quentes sanitárias 21,6 kWh/m².ano
- What it is
- The letter broken into the three uses that make it up. This is where you see where the problem actually is: a high heating figure points at the envelope and the glazing; a high hot-water figure points at the water-heating equipment, which is far cheaper to replace.
- What is ordinary
- On the Portuguese mainland heating nearly always dominates these three figures and cooling is small. A profile with high heating and low cooling is the national pattern, not a fault in the property.
- What stops or delays a purchase
- These are per square metre per year, against a standardised pattern of use — they are not a forecast of your bill. They are for comparing properties with each other and for working out which work would actually change anything. This needs verifying before you commit.
Fontes de energia
Eletricidade (aquecimento) · Gás natural (águas quentes sanitárias)
- What it is
- Which energy feeds each use. It matters because the cost per kWh differs sharply between electricity, mains gas, bottled gas and biomass — two properties with the same class can cost different amounts to heat.
- What is ordinary
- Mixed set-ups are normal: electricity for heating and gas for hot water is among the commonest in an urban flat. Mains gas implies a network connection and a contract of its own.
- What stops or delays a purchase
- Confirm the connection described actually exists and is live — a certificate can describe a gas installation that was since disconnected. And if you intend to change fuel, the cost of doing so is yours, not the seller's. This needs verifying before you commit.
Envidraçados e isolamento
Vidro duplo, caixilharia de alumínio sem corte térmico · Cobertura isolada · Paredes exteriores sem isolamento térmico
- What it is
- The physical description of what separates inside from outside: walls, roof, floors and glazed openings. It is the part of the certificate that explains the letter, and the part that costs most to change.
- What is ordinary
- "Double glazing in frames without a thermal break" is extremely common in 1990s and 2000s construction: the glass was upgraded, the frame was not. Uninsulated walls are the norm across much of the pre-2006 stock.
- What stops or delays a purchase
- Insulating walls externally on a fraction means touching the façade, which is a common part — that is not a decision you take alone; it depends on the owners' association and may depend on the municipality. Before costing envelope improvements you need to know what the horizontal-property rules allow. This needs verifying before you commit.
Sistemas técnicos
Aquecimento: bomba de calor (split) · Arrefecimento: não existe · AQS: esquentador a gás natural
- What it is
- The equipment installed for heating, cooling and hot water, with its efficiency. It feeds straight into the class calculation and, unlike the envelope, is relatively cheap to replace.
- What is ordinary
- "None" is a legitimate and frequent answer: many flats have no cooling, and the certificate then assumes a reference appliance for calculation purposes. Equipment at the end of its life still counts as present.
- What stops or delays a purchase
- The certificate records that the equipment exists, not that it works or has been serviced. The age and actual condition of the appliances show up at the viewing and in service records, not here. This needs verifying before you commit.
Tipologia e área útil de pavimento
T2 · Área útil de pavimento 85,0000 m²
- What it is
- The tipologia matches the caderneta, but the area does not — and should not. The certificate uses área útil de pavimento, measured internally and corresponding to the space actually heated; the caderneta uses área bruta privativa, measured to the outer perimeter and the centre lines of the walls, and separates the área bruta dependente from it.
- What is ordinary
- On this model: 85.0000 m² useful against 96.5000 m² of área bruta privativa. The difference is the thickness of the walls. The garage, which is 22.0000 m² of área bruta dependente on the caderneta, does not enter the useful area at all because it is not heated space.
- What stops or delays a purchase
- Three documents, three numbers, and only one of them would be an error. A useful area close to — or above — the área bruta privativa is what would be odd. What needs checking is whether all three reconcile with each other and with the licensed plan. This needs verifying before you commit.
Medidas de melhoria
Caixilharia com corte térmico — € 4 200, retorno ~11 anos · Isolamento de paredes pelo interior — € 3 100, retorno ~14 anos · Bomba de calor para AQS — € 1 800, retorno ~6 anos
- What it is
- The part of the certificate almost nobody opens. The expert lists the works that would raise the class, with an estimated cost and an expected payback. In practice it is a schedule of works costed by a technician and handed to both sides before the negotiation.
- What is ordinary
- The estimates are indicative and priced in the year of issue — on a certificate from 2017, like this one, the costs are out of date and almost certainly low. Paybacks over ten years are normal for envelope measures and do not mean the measure is bad.
- What stops or delays a purchase
- This list is a negotiating fact: works the property needs, identified and costed by a technician the seller paid for, in the document the seller handed you. Re-cost them at today's prices before using them, and establish which ones depend on the owners' association. This needs verifying before you commit.
What the document does not tell you
O que o banco faz com esta letra
- What it is
- The energy class feeds into the valuation the bank commissions, and the bank lends against the LOWER of the agreed price and the valuation. A C like this model's is not bad, but it does not help either: it is the class much of the stock carries, and it adds nothing to value. A class that pulls the valuation below the price does not stop the purchase — it moves the difference into the deposit, which comes out of your pocket. Some banks also price high-class properties differently, which varies between institutions and over time.
- What is ordinary
- A bank valuation landing below the price is common in a rising market, and the energy class is only one input. It is not in itself a sign that the seller has priced the property wrongly.
- What stops or delays a purchase
- Before signing a promissory contract with a deposit, you need to know how much the bank will lend against this specific property, not against a property in the abstract. This needs verifying before you commit.
The scale, A+ to F
The scale has eight classes, not seven — B- exists, and it is the one that lands exactly on the regulatory limit. Each class is an interval of the ratio Rₙₜ, published in Table 01 of Despacho (extrato) n.º 15793-J/2013.
Rₙₜ = Nₜₑ ÷ Nₜ — the property's nominal annual primary-energy need divided by the regulatory limit for that property.
Ranges: Despacho (extrato) n.º 15793-J/2013, Table 01. Colours: ADENE, Manual de Normas Gráficas — Classe Energética do Imóvel, p. 12.
The scale is relative, and it is not a consumption figure
The letter does not measure energy — it measures a ratio. The numerator is what the property needs; the denominator is the regulatory limit calculated FOR THAT property, which varies with climate zone, typology and envelope. The same building, moved to another climate zone, does not necessarily get the same letter, because the reference it is measured against has changed. Two houses with a C can spend very different amounts.
The letter is as old as the regulation that issued it
This model's certificate was issued in 2017, so it was classified under Decreto-Lei n.º 118/2013, with the classification rules in Despacho (extrato) n.º 15793-J/2013. A class issued under an earlier regulation is that regulation's classification, and it does not convert itself. Comparing the letter on a nine-year-old certificate with one issued this year is comparing two rulers.
Where the class actually bites
- In the bank's valuation. The class is one of the inputs, and the bank lends against the lower of price and valuation — any gap comes out of the deposit.
- In IMI, where the município decides to. Some municipalities apply IMI reductions to more efficient properties; it is a municipal decision, it varies between councils and between years, and it is confirmed with the município, not here.
- In the direction European regulation is travelling. The energy performance of buildings directive points toward rising minimum requirements on existing stock. What that means for a specific property depends on transposition and timing, which are still being settled.
None of these points is settled by reading the letter. What the letter does is tell you which questions to ask about this particular property — of the bank, of the município and of the expert. This needs verifying before you commit.
The other two documents on the same property
This is the only one of the three that is not a register. The caderneta predial and the certidão permanente describe the property as the registers hold it — tax and title; the certificate describes it as built. That is why the same fraction comes with three different areas, all of them correct: the cleanest example of why none of these documents is read on its own.
How to read a Portuguese caderneta predial →How to read a Portuguese land registry certificate (certidão permanente) →Where the three documents read differently
The three models describe the same fração «F» of artigo U-00000. Only the first of these points is a genuine mismatch between the registers — the rest are differences of scope, of currency and of measuring convention, where the documents say different things without contradicting each other. They are all here because they are exactly the points that trip people up on real documents.
Who is shown as the holder
Caderneta predial: MARIA EXEMPLO DA SILVA and JOÃO MODELO EXEMPLO, 1/2 each — the 2011 buyers.
Certidão permanente: Three heirs holding in common after JOÃO's death in 2021, with a life usufruct for MARIA.
On your own documents: This is the classic lag: the tax register only updates when the parties file, the land registry updates with the act. Who can sell is whoever holds title at the land registry. When you meet this divergence on your own documents, treat the certidão as the source and ask why the tax register was never updated. This needs verifying before you commit.
Which areas each register prints (not a mismatch)
Caderneta predial: The same fraction areas — 96.5000 + 22.0000 m² — and, IN ADDITION, the BUILDING's areas: 480.0000 m² of land and a 160.0000 m² footprint.
Certidão permanente: The same fraction areas — 96.5000 + 22.0000 m² — and nothing else. The 480 m² plot sits on the building's parent description, not on this entry.
On your own documents: Note that the fraction's areas agree across both documents: there is no mismatch here, there is a difference in scope. The caderneta prints, on the same page, figures that belong to the building; the certidão does not. The land on a fraction's caderneta is a common part of every owner and is not yours. Add only the privativa and the dependente to know what you are buying. This needs verifying before you commit.
How long each document stays reliable
Caderneta predial: A snapshot of the day it was pulled — on this model, 23-09-2026. It does not update afterwards.
Certidão permanente: A subscription with an access code, valid six months; it always shows the register as it now stands.
On your own documents: That is why you ask for a caderneta pulled on the day and check the certidão through the code rather than a PDF. A three-month-old document is not false — it is simply older than anything registered since. This needs verifying before you commit.
Three documents, three areas (none of them wrong)
Caderneta predial: Área bruta privativa 96.5000 m² plus área bruta dependente 22.0000 m², measured to the outer perimeter and the centre lines of the walls (CIMI art. 40.º).
Certidão permanente: The same fraction areas, 96.5000 + 22.0000 m², as entered on the register.
On your own documents: The energy certificate adds a third: 85.0000 m² of área útil de pavimento, measured internally and counting only heated space — which is why it is smaller than the área bruta privativa and leaves the garage out entirely. The three numbers describe the same fraction by different criteria. Be suspicious when the useful area approaches the área bruta privativa, not when it falls below it. This needs verifying before you commit.
What the certificate does not answer
The letter, the indicators and the improvement measures are all on this sheet, and you now know where to find them. What the sheet does not say is whether the certificate survives to the deed, who pays for the next one, which of the listed works depend on the owners' association, and how much the bank will lend once the valuation has read this class.
Those are questions about a specific property and a specific deadline — they are what we handle in Contract & Deed Representation, with no seller commission.
Sources
- Código do IMI, artigo 40.º — n.º 2 and n.º 3 give the wording used above for área bruta privativa and áreas brutas dependentes, and set the coefficients at 1 and 0.30. (Article 40.º-A is a different provision: the area adjustment coefficient.)
- Decreto-Lei n.º 108/2026, de 29 de maio — its article 3.º gives the RJUE a new article 4.º-A, whose n.º 14 requires the urbanistic title to be mentioned on pain of the transaction being voidable.
- Declaração de Retificação n.º 29-A/2026/1 — checked against article 4.º-A: it corrects only article 1.º d) of the diploma and article 3.º n.º 3 c) of Decreto-Lei n.º 555/99, so n.º 14 above stands in its original wording.
- Decreto-Lei n.º 155-B/2026, de 31 de julho — its article 2.º amends article 13.º of the diploma above and sets it in force on 1 October 2026.
This page explains what the fields on these documents mean. It is not legal or tax advice, and no document shown here corresponds to a real property. Soverite is a buyer's agent licensed under AMI 27281.