Energy performance certificate in Italy (APE): classes, validity and what it means for your house

An energy performance certificate is the document that rates how much energy a building uses, on a standard basis, for heating, cooling, hot water and ventilation. In Italy it is called the attestato di prestazione energetica, or APE, and it gives the building a letter from A4 (most efficient) to G. If you are buying, selling, renting, building or renovating a house in Italy, you will meet this energy performance certificate several times: in the advertisement, during the negotiation, in the sale contract and again at the end of building works.

This guide explains how to read an Italian energy performance certificate, when it is compulsory, who is allowed to issue it, how long it stays valid and what an architect checks when the house is still at design stage. It is written by Federico Cappellina Architects, an architecture practice in Verona that designs houses in north-east Italy and Lombardy and supervises their construction, for foreign owners and buyers who are not familiar with the Italian system.

The laws are linked to Normattiva, the official database of Italian legislation; the ministerial decree of 26 June 2015 is quoted from its text in the Official Gazette; our suggestions on how to use the certificate when choosing or designing a house are our own practice and are marked as such. This is not legal advice and not an energy certification: the rating of a real building is given only by the qualified technician who inspects it.

Energy performance certificate in brief

The energy performance certificate (APE) assigns one of ten classes, from A4 to G; the main indicator is annual global energy need in kWh per square metre per year (ENEA).
Under the decree of 26 June 2015, the class is set by the global energy performance index expressed in non-renewable primary energy.
An energy performance certificate is needed to build, sell and let, and must exist before the certificate of habitability for new buildings and major renovations (Legislative Decree 192/2005, Article 6).
It is valid for a maximum of ten years, subject to the checks on heating systems, and must be updated after works that change the class.
Sale and rental advertisements must show the energy performance indices and the corresponding energy class.
The rating is calculated on standard use: it is not your bill, and it says nothing about planning compliance or architectural quality.

Energy performance certificate and quality of living: lounge opening onto the pool at SD Home in Soave, a project by the studio — SD Home, Soave (Verona): a project by the studio, shown as a reference of language, not as an example of a specific energy class.

What an energy performance certificate is and what it measures

Legislative Decree 192/2005 defines, in Article 2, the energy performance of a building as the annual amount of primary energy consumed, or expected to be consumed, to meet the needs linked to standard use: winter and summer climate control, domestic hot water, ventilation and, for non-residential buildings, lighting and lifts.

The energy performance certificate is the document that expresses this performance through specific indicators, is issued by qualified and independent experts and contains recommendations to improve efficiency. The class is its summary in a letter: a scale of ten classes, from A4 to G, where A4 identifies the most efficient buildings.

Two words in the legal text matter more than all the others: «standard use». An energy performance certificate is not drawn from the bills of the people living in the house, but from a calculation that assumes conventional conditions. Two villas with the same class can therefore consume differently, and a family that keeps the windows open all winter does not make its house fall into a worse class.

The certificate measures how well the building and its systems answer a conventional demand; actual consumption also depends on the people who live there. If you know the systems of other countries, treat the Italian letter as a calculated rating of the building, not as a meter reading.

The ten classes, from A4 to G

According to the ENEA page on the APE, performance is linked to ten classes, from A4 to G, and the main indicator is the global annual energy need in kWh/m² per year. The decree of 26 June 2015 defines the class through the global energy performance index referred to non-renewable primary energy.

The numerical limits between classes are in the national guidelines annexed to the decree, which are published in graphic form: we do not quote them because we could not read them as text; the scale is printed on the first page of every energy performance certificate.

One thing is clear from the decree: the class is calculated on non-renewable primary energy. For the same energy need, a house that covers a significant part of its demand with renewable energy produced on site, for example with photovoltaic panels, obtains a more favourable energy performance certificate than a house that depends entirely on non-renewable sources. This is one reason why the design of the envelope and of the systems are decided together.

How to read an energy performance certificate: the mandatory content

Article 4, paragraph 4, of the 2015 decree lists the information that every certificate must contain, «under penalty of invalidity». It shows why a single letter is not enough:

the global energy performance, in terms of total primary energy and non-renewable primary energy, with the corresponding indices;
the energy class, set by the global non-renewable energy performance index;
the energy quality of the building fabric for heating and cooling, through the useful thermal performance indices for winter and summer climate control;
the reference values, such as the minimum energy efficiency requirements in force;
carbon dioxide emissions;
exported energy;
recommendations to improve efficiency, with the most significant and economically convenient measures, distinguishing major renovations from energy upgrades.

Every energy performance certificate also reports information on financial incentives and on the opportunity of an energy audit. In our practice, the first thing we look at is not the letter but the pair of indices: the one describing the building fabric (how well the envelope keeps heat in during winter and out during summer) and the global one, which adds the systems.

A middle class with a weak envelope and a very efficient heating system describes a different house from a middle class with a well-built envelope and ageing systems: the second opens more options.

How the rating of an energy performance certificate is set

An energy performance certificate cannot be estimated by eye or completed online with four questions: the 2015 decree requires the technician who issues it to make at least one site inspection of the building or unit, to collect and verify the data. The calculation considers the building fabric (walls, roof, ground floor, windows, thermal bridges), the systems (generator, distribution, emitters, hot water, ventilation), the renewable sources installed and the climatic zone of the site. The calculation methods, including simplified ones for small buildings of modest energy quality, are defined by the guidelines decree.

For the energy performance certificate to be reliable, true documents are needed: build-ups of walls and roof, type and age of windows, system data and the system logbook. Where these are missing the technician applies default values, which tend to penalise the building: a villa with a good envelope but no papers may therefore receive a worse class than its real one. Under the decree, system logbooks are attached to the certificate, as the original, as a paper copy or in electronic form.

When an energy performance certificate is compulsory

Article 6 of Legislative Decree 192/2005, in the text we read, sets out the cases in which the certificate is needed:

New buildings and major renovations: the certificate must be produced before the certificate of habitability, by the builder.
Sale and transfers free of charge: the owner provides the certificate if the property does not already have one, makes it available at the start of negotiations and hands it over at the end.
New lettings: the same duty applies when the property is let to a new tenant.
Properties sold or let before construction: the certificate must be produced within fifteen days of the request for the certificate of habitability.
Advertisements: in sale or rental offers, on all commercial media, the energy performance indices of the envelope and the global index and the corresponding energy class must appear; residential buildings let for less than four months a year are excluded.
Contracts: sale contracts, transfers for consideration and new registered lettings include a clause in which the buyer or tenant declares that they have received the information on the certificate; a copy is attached, except for lettings of single units.

The same article states that a single certificate may cover several units in the same building only if they share the same use, surroundings, orientation, geometry and climate-control systems. For a detached villa the question does not arise; for a small block or a pair of semi-detached houses it does, and the engagement should say whether separate certificates or a single one are wanted.

Energy performance certificate and major renovation

Legislative Decree 192/2005 defines, again in Article 2, a first-level major renovation as work on an existing building that affects more than a quarter of the surface of the envelope of the whole building, including all units: typically the rebuilding of external walls, external plaster, the roof or waterproofing. The text we read does not give the definition of a second-level renovation, so we do not describe it; anyone renovating should check in the current text which category the works belong to, because requirements depend on it.

The practical consequence for the owner: if the renovation is a major one, the energy performance certificate must exist before the certificate of habitability, and the result after the works is something to design, not to discover at the end.

In our practice, when a renovation touches the envelope, the target class is discussed with the client in the early phases of the house design process and compared with the budget set in the guide to the cost of renovating a house in Italy. The final class cannot be promised in advance: it is estimated at design stage and verified by calculation.

Energy performance certificate and the design of a new villa

For a new building the energy performance certificate is the last step of a path that starts long before. Article 8 of Legislative Decree 192/2005 requires the designer to include calculations and checks in the technical report of the design, which the owner files with the municipality together with the notice of start of works or the application for the building title. For new buildings and major renovations, the report must also contain an assessment of the technical, environmental and economic feasibility of high-efficiency alternative systems (renewables, cogeneration, district heating, heat pumps, monitoring systems).

At the end of works, under the same article, the site manager (direttore dei lavori) certifies the conformity of the works and the energy qualification certificate «as built», to be submitted to the municipality with the declaration of completion; without these documents the declaration of completion has no effect.

The energy qualification certificate is a different document from the energy performance certificate: Article 6 describes it as optional and states that it does not replace the energy performance certificate, as must be written on its cover. The municipality keeps the documents and may carry out checks during works or within five years of the declared end of works, also at the request of the owner, buyer or tenant, at their expense.

The decree also defines the nearly zero-energy building: a building with very high energy performance, whose very low or nearly zero energy need is covered to a significant extent by renewable energy produced on site. The minimum requirements set by the decree provided for in Article 4 establish what this means for a new building; we have not read them and do not quote them.

For our work the idea is simple: the rating of an energy performance certificate is decided by the shape of the house, its orientation, the size and position of openings, the quality of windows and the continuity of insulation, before the systems. We expand on this in our guide to eco-friendly house design.

Who issues an energy performance certificate

The certificate is issued by a person qualified under Presidential Decree 75 of 16 April 2013, Article 2. The decree lists as qualified subjects authorised technicians (freelance or employed), public bodies operating in energy and construction, public and private bodies accredited under the UNI CEI EN ISO/IEC 17020 standards and energy service companies (ESCOs), the last three with technicians on staff.

The technician must hold one of the listed qualifications (degrees in certain classes, technical diplomas, the surveyor’s diploma and others), be registered with the relevant professional body where there is one and be licensed to design buildings and systems; alternatively, a technician may be qualified for energy certification only, after a course with a final exam.

How do you check, in practice? In our practice we recommend three checks: ask for the professional’s name, qualification and registration number; make sure the engagement includes the site inspection and the calculation documents; and check that the certificate is filed in the regional register (see below).

The law speaks of «qualified and independent» experts: for an existing building it is sensible that the certifier has no interest in the sale or in the firm doing the works; for a new building, where the design calculation is done by the design team, it is common for the final certificate to be signed by the same thermal engineer, provided the data are those «as built».

How long an energy performance certificate remains valid

The decree of 26 June 2015 (Article 4, paragraph 3) and Article 6 of Legislative Decree 192/2005 set a maximum validity of ten years from issue. It applies on one condition: that the rules on efficiency checks of heating systems, set out in Presidential Decree 74/2013, are respected.

If not, the certificate lapses on 31 December of the year after the first missed deadline. This is why the system logbooks are attached to the certificate, and why, when you buy a house, an energy performance certificate that is «still valid» on paper still deserves a check of the maintenance of the system.

The certificate must also be updated after any renovation or upgrade of building elements or systems that changes the energy class. Article 6 adds that when a technical system is installed, replaced or improved, the performance of the modified part must be analysed and documented and, where provided, a new certificate issued. Anyone who replaces the boiler, adds external insulation or changes the windows before selling should ask the technician whether the class has changed: an old but «valid» energy performance certificate may describe a house that no longer exists.

Where to find the energy performance certificate of a house in Veneto

A buyer can check whether a certificate already exists. The Veneto Region page explains that registration in the regional archive can be checked only for certificates submitted through the online application Ve.Net.energia-edifici, compulsory since 2 May 2012.

There are two functions: a search by number, year and key, which shows the certificate and lets you download the PDF file; and a «check existence of certificate» function, which asks for the cadastral municipality, sheet and parcel (and, if needed, sub-unit and section) and, if it finds a result, does not provide the document but gives the number and year of the certificate, the details of the certifier and the certifier’s certified e-mail address.

To obtain a duplicate or the key you must contact the certifier. The page shows 21 October 2024 as its latest update; procedures may change and should be checked on the regional website.

On the Ve.Net.energia-edifici portal the Region tells certifiers that from 1 December 2022 only certificates conforming to XML schema version 12 are registered, and that automatic consistency checks at upload can lead to rejection. At national level, under the 2015 decree, ENEA runs the SIAPE database, fed by the regions; citizens can access it only in aggregate form.

The regions must also set up control plans that analyse at least 2% of the certificates filed each year, giving priority to the most efficient classes: a certificate with a very high class may therefore be checked more closely than an average one.

What an owner risks by not complying

Article 15 of Legislative Decree 192/2005 provides administrative penalties. In the text we read (the version in force from 4 August 2013, so to be re-checked in the current text) a builder or owner who does not provide an energy performance certificate for a new building or a major renovation is fined between 3,000 and 18,000 euros;

the same range applies to an owner who does not provide the certificate on a sale; 300 to 1,800 euros for a new letting; 500 to 3,000 euros for an advertisement that does not show the energy parameters; and 700 to 4,200 euros for a professional who issues a certificate without respecting the criteria and methods.

Article 6 also provides a fine of 3,000 to 18,000 euros for failing to declare or attach the certificate in contracts, payable jointly by the parties. Amounts and cases must be checked in the updated text with an adviser: our aim is to show that the energy performance certificate is not a detail to leave to the notary at the last minute.

Buying a house: questions to ask about the energy performance certificate

In our practice, when a client considers buying a villa, the energy performance certificate is read together with the other documents and never alone. The questions are always the same:

When was it issued? A certificate ten years old is at its limit; a recent one may still not reflect later works.
Did the technician inspect the house? The decree requires it; if the data are generic, the rating is less reliable.
What are the systems like, and who checks them? Ask for the system logbook and proof of periodic checks, because the validity of the certificate depends on them.
What is the class of the envelope, and what is that of the systems? The two indices show where the margin for improvement lies.
Are the recommendations realistic? The certificate distinguishes major renovations from upgrades: each is priced with a quotation, not with an impression.
Do the building data match the building titles? A surface or volume different from the authorised ones is a warning: the certificate does not check legitimacy but relies on the geometry of the building.

The last point recalls something the certificate does not settle: it says how the building performs, not whether it was built in conformity with its permits. That check is a separate one, described in our guide to the planning compliance check; the starting data for what can be built are in the urban planning certificate.

Energy performance certificate and construction details: corridor at MD Home in Verona with light integrated into white walls, a project by the studio — MD Home, Verona: a project by the studio, shown as a reference of language for details, not as an example of an energy class.

How to improve the rating: the order of works

The recommendations of the energy performance certificate are a starting point, not a design. In our practice, for an existing house, the order of reasoning is the following; we present it as a method, not as a guaranteed result:

Envelope first: insulation of roof and walls, replacement of windows, treatment of thermal bridges. A better envelope reduces the need and allows smaller systems.
Then the systems: generator, distribution, emitters and, where useful, controlled mechanical ventilation, sized on the new need, not the old one.
Finally renewables: photovoltaic panels and, where sensible, solar thermal, because they act on the non-renewable primary energy on which the class depends.
Summer comfort: shading and thermal mass, often neglected when a house is only insulated and not designed for the heat.

Before choosing each measure we ask the technician to simulate the class each would produce, and compare the result with the cost estimated in the bill of quantities. Once works are under way, site supervision checks that the build-ups and systems actually built match those in the calculation: this is what makes the final energy performance certificate credible. Where several firms work on site, the building site also needs the steps described in our guide to construction site safety in Italy.

The European directive on the energy performance of buildings

According to the European Commission page on the directive, Directive (EU) 2024/1275 on the energy performance of buildings entered into force on 28 May 2024 and was to be transposed by the member states by 29 May 2026. The page says that certificates will be based on a common template and common criteria for performance classes and will become digital, and that zero-emission buildings will become the standard for new buildings.

We have not verified how and when Italian transposition will amend Legislative Decree 192/2005, or whether the A4 to G scale will change: until this is read in the current text, the rules described in this guide apply. Anyone designing a house to be delivered in a few years should ask the technician whether the design remains consistent with the new framework.

Frequent mistakes with the energy performance certificate

Taking the class for real consumption: the calculation is standard, the bill is not.
Ordering the certificate from someone who does not visit: the decree requires an inspection, and without real data the rating may be better or worse than the truth.
Forgetting the system checks: the certificate lapses if the deadlines for system checks are missed.
Not updating the energy performance certificate after works that change the class.
Omitting the class from advertisements: indices and class must appear on all commercial media.
Confusing the APE with the energy qualification certificate: the second is optional and does not replace the first.
Thinking the certificate settles building compliance: they are separate checks.

Italian terms at a glance

APE (attestato di prestazione energetica): the energy performance certificate.
Classe energetica: the energy class, from A4 to G.
Attestato di qualificazione energetica: the optional energy qualification certificate, which does not replace the APE.
Certificatore: the qualified technician who issues the APE.
Agibilità: the certificate of habitability, required before the building is used.
Direttore dei lavori: the site manager, who certifies conformity of the works at completion.
Libretto di impianto: the system logbook, attached to the certificate.
SIAPE: the national database of energy performance certificates, run by ENEA.

Documents for the energy performance certificate: the checklist

Building titles and drawings of the existing state, for the geometry.
Build-ups of walls, roof and ground floor, if available; the technical report of the design (Article 8) for recent buildings.
Window characteristics: frame, glass, year of installation.
System logbook and proof of periodic checks.
Data on heat pump, boiler, ventilation, photovoltaic or solar systems.
Any previous energy performance certificate and its recommendations.
For new buildings: the energy qualification certificate and the site manager’s certification submitted with the declaration of completion.

Energy performance certificate and systems: dark interior with reflective surfaces at MD Home in Verona, a project by the studio — MD Home, Verona: a controlled interior, a project by the studio; a reference of language, not an example of a system or energy class.

Energy performance certificate: frequently asked questions

What is an energy performance certificate in Italy?

It is the attestato di prestazione energetica (APE): a document issued by a qualified technician that rates the energy performance of a building with a class from A4 to G, based on the global non-renewable primary energy index, and lists recommendations to improve it. It describes standard use, not actual consumption.

When is an energy performance certificate required?

For new buildings and major renovations before the certificate of habitability, on a sale or transfer free of charge, for new lettings, and in advertisements, which must show the indices and class (Legislative Decree 192/2005, Article 6).

How long is an energy performance certificate valid?

At most ten years from issue, provided the checks on heating systems are respected; otherwise it lapses on 31 December of the year after the first missed check. It must be updated after works that change the class.

Who can issue an energy performance certificate in Italy?

A person qualified under Presidential Decree 75/2013: authorised technicians with the qualifications listed in Article 2, public bodies, accredited bodies and ESCOs with technicians on staff. The technician must make at least one site inspection.

Do I need an energy performance certificate to build a new villa?

Yes: for new buildings the certificate must be produced before the certificate of habitability. The design also includes the technical report of Article 8 and, at the end, the site manager certifies conformity of the works.

How can I check whether a house in Veneto already has an energy performance certificate?

In the regional register Ve.Net.energia-edifici: the Region offers a search by number, year and key and a check of existence by cadastral data. For a duplicate or the key you contact the certifier. Procedures should be checked on the Region’s website.

Does the energy performance certificate show that the house is legally built?

No. It describes energy performance; planning and building compliance is checked against the building titles and the existing state, as explained in our guide to the planning compliance check.