The basic rule: only one genuinely mandatory certificate

The energy passport (Energiepass, or energy performance certificate) is mandatory for any sale and any rental of a residential building. Its framework is set by the amended Grand-Ducal Regulation of 30 November 2007 on the energy performance of residential buildings, reinforced by the Grand-Ducal Regulation of 9 June 2021. Since 1 July 2021, handing it to the buyer or tenant is a legal obligation.

Often overlooked: it must be valid before the listing is published, not just produced at the notary. Advertising a property without a valid passport exposes the seller or landlord to a fine of up to 5,000 euros. It is valid for ten years and must cover the whole period, from listing to signature of the deed. Budget roughly 430 to 600 euros excluding VAT for a single-family house.

How to read an energy passport correctly

Do not stop at the overall letter, which runs from A+ (the best) to I (the worst). The document distinguishes several indicators: energy performance (primary energy demand), thermal insulation performance (heating demand) and environmental performance (CO2 emissions).

The reading tip that reveals the real condition of the property: compare thermal insulation with overall performance. Good insulation paired with a poor overall grade almost always points to an old, energy-hungry heating system that needs replacing. Conversely, poor insulation signals work on the building envelope (facade, roof, windows), which is far heavier. Finally, read the list of recommendations at the end of the report: it prices the priority works. Moving from class F to class C can represent a significant budget, and that is a perfectly legitimate negotiation lever.

Asbestos: not a sale survey, but a serious matter as soon as works are involved

This is where the misunderstanding with France is most common. You sometimes read that an asbestos survey is mandatory for properties whose permit predates 1991. That threshold is a French reference, not a Luxembourg one. In the Grand Duchy, there is no asbestos survey attached to the deed of sale: the sale alone triggers no asbestos report.

The Luxembourg framework lies elsewhere. Placing asbestos-containing materials on the market has been banned since 2001. And as soon as works are planned, the Grand-Ducal Regulation of 4 July 2007 on protecting workers from asbestos-related risks applies: identifying materials likely to contain asbestos, notifying the works to the Labour and Mines Inspectorate (ITM), and using qualified operators and laboratories all become mandatory. So it is a protection regime tied to works, not a transaction formality.

In practice: "presence of asbestos" in an older property is not an alarm in itself. What matters is its condition. Non-friable, stable asbestos poses no risk as long as the materials are not drilled or broken. The removal budget arises at renovation time. For a buyer planning works on a pre-2001 property, the asbestos inventory should therefore be built into the costing from the start.

Lead, electricity, gas: recommended, not mandatory for a sale

None of these checks is required by law to complete a residential sale in Luxembourg. That does not make them pointless.

• Lead. Not mandatory, but relevant in older buildings, where it is mainly found in old paint. The risk appears at renovation: sanding lead-painted woodwork releases toxic dust. Worth identifying before any stripping work.
• Electricity. No mandatory electrical survey for a sale. Bringing the installation up to standard may, however, be required by the grid operator during a connection or a major change to the installation. Watch for: missing earthing, an obsolete fuse board, unsafe sockets in wet rooms. A fuse board needing full replacement quickly runs into several thousand euros.
• Gas. No survey obligation for a sale. Check the date of the boiler's last service and the condition of the flue.

Radon: not mandatory, but worth checking depending on the municipality

Radon, a natural radioactive gas, is more present in the north of the country, classified as a high-risk zone (more than 5% of houses there exceed the national reference level of 300 Bq/m3). There is no obligation to measure it to sell a home, nor even to live in one, including in a priority zone.

It remains a useful point of vigilance. Radon measurement is free for all Luxembourg residents, and the average concentration per municipality is available from the authorities. If the property is in an exposed zone and the living areas are on the garden level or in a converted basement, a dosimeter measurement is recommended. Solutions are often simple (better ventilation, sealing slabs) and support exists for remediation works. Note for investors: measurement obligations already apply to workplaces located in radon zones.

France or Luxembourg: the table that sets the record straight

The real Luxembourg risk: the warranty against hidden defects

Less paperwork does not mean less risk. It is in fact the opposite, and few sellers anticipate it. The Luxembourg Civil Code imposes a warranty against hidden defects on the seller: under article 1641, the seller is liable for hidden defects that make the property unfit for its use or that significantly reduce its value. Apparent defects, however, are not covered (article 1642).

A buyer who discovers a serious, hidden defect has two options: the rescissory action (cancelling the sale, refund of the price and, where applicable, damages) or the estimatory action (keeping the property and obtaining a price reduction after expert assessment). The defect must be reported within a short time of being discovered.

The non-warranty clause changes things, but not as much as people think. Between two private individuals it is valid and appears in most deeds. However, it loses all effect if the seller acted in bad faith, meaning they knew about the defect and concealed it (article 1643). In other words, the clause never protects someone who lied.

What this means in practice

If you are selling

• Have a valid energy passport drawn up before publishing the listing. It is the entry condition, not a last-minute formality.
• Gather the evidence: work invoices, boiler servicing, warranties, plans. This supports the price and reduces the risk of dispute.
• For a pre-2001 property where the buyer is likely to carry out works, an anticipated asbestos inventory signals seriousness.
• Declare known defects. Silence costs more than a negotiated reduction, and it voids the non-warranty clause.

If you are buying

• Insist on a valid energy passport and read the detailed indicators, not just the overall letter.
• Ask for the history of works and servicing.
• Check the municipality on the radon map if the property is in the north or has living areas in the basement.
• If you plan to renovate a pre-2001 property, build the asbestos inventory and any removal into your budget from the start.

Frequently asked questions

Which surveys are mandatory to sell in Luxembourg?
Only one document is systematically mandatory: the energy passport. It must be valid before the listing is published and remain so until the notarial deed.

Is the energy passport also mandatory for renting?
Yes. It is required for both sale and rental of a residential building, and must be handed to the buyer or tenant.

How long is an energy passport valid?
Ten years from its date of issue. After that it has no legal value for the transaction and must be redone.

Do you need an asbestos survey to sell in Luxembourg?
No, not for the sale itself. Asbestos obligations (identification, ITM notification) apply before works on a building predating 2001.

Is radon an obstacle to buying in Luxembourg?
No measurement is mandatory for a sale. It is a targeted point of vigilance, mainly in the north and for homes with living areas in the basement. Measurement is free for residents.

Does the seller remain liable after the sale?
Yes, under the warranty against hidden defects (article 1641 of the Civil Code). A non-warranty clause protects a good-faith seller, but not one who concealed a known defect.

Sources and legal basis

• Energy passport: Guichet.lu (Grand-Ducal Regulations of 30 November 2007 and 9 June 2021).
• Asbestos: Labour and Mines Inspectorate (ITM) and Grand-Ducal Regulation of 4 July 2007.
• Radon: Health Portal, reference level 300 Bq/m3.
• Warranty against hidden defects: articles 1641 to 1643 of the Civil Code.

This article is for information only and does not constitute legal advice. Regulations evolve and each situation is specific. Before any decision, check the texts in force at the date of your project and consult your notary or a legal adviser. Information up to date at the time of publication.

By David Carmo, founder of CARMO Immobilier. A real estate professional since 2008, board member of the Real Estate Chamber of the Grand Duchy of Luxembourg, member of its disciplinary council, and trainer at the Real Estate Academy.