When you inherit property in Luxembourg — whether a family home in Strassen, an apartment in Kirchberg, or a rural building in the north — one of your first obligations is filing the déclaration de succession with the Administration de l'Enregistrement et des Domaines. At its heart sits a single, deceptively simple question: what is the property worth?
The answer matters more than most heirs realise. Get it wrong on the low side, and you risk a tax adjustment plus penalties. Get it wrong on the high side, and you pay inheritance tax on value that simply isn't there. This guide walks through the entire process — methodically, with real Luxembourg context.
What value must be declared
Luxembourg law requires the market value at the date of death (valeur vénale au jour du décès). Not the purchase price decades earlier. Not the fiscal reference value. Not a rough guess based on what the neighbour sold for last year. The market value is the price the property would realistically achieve in an open-market sale within a reasonable timeframe under normal conditions.
This figure becomes the basis for several calculations: the inheritance tax (droits de succession), the registration duties, and — importantly — the acquisition cost basis for any future sale by the heirs. A low declaration today saves nothing in the long run; it merely shifts the tax bill to later, often with interest.
When a professional valuation is required
Strictly speaking, the law does not mandate a professional valuation report. Heirs can declare a value themselves. In practice, however, the Administration may challenge declarations that look implausible — and challenges are increasingly common since the digitisation of cadastral and transaction data.
A professional valuation is strongly recommended whenever:
- The property is worth more than €500,000 (the threshold above which scrutiny intensifies)
- There are multiple heirs with diverging interests (e.g., siblings, where one wants to buy out the others)
- The property has unusual features: emphytéose (Erbpacht), shared ownership, easements, agricultural land, or commercial use
- The estate includes properties in different communes with different price dynamics
- A divorce, partnership dispute, or business succession is also involved
In each case, an independent third-party report is the cleanest way to establish a defensible figure.
The three valuation methods, applied to inheritance
A complete valuation in Luxembourg combines at least two of the three internationally recognised methods.
Comparison method (méthode comparative)
The most common approach for apartments and standard single-family homes. The valuer identifies recently sold comparable properties — same commune, similar surface area, similar year of construction, similar energy class — and adjusts for material differences. In Luxembourg this method works well in dense markets like Luxembourg City, Esch-sur-Alzette, or the southern industrial belt, where transaction volume is high. It struggles in low-volume rural communes where genuinely comparable sales may be a year old or further away.
Income approach (méthode du rendement)
Applied to rental and commercial properties. The valuer estimates the gross potential rental income, deducts operating costs and a vacancy allowance, and capitalises the net result at a market yield. For a rental apartment in Belair, that yield typically sits between 3% and 4% in 2026; for older multi-family buildings in less central locations, 4.5% to 5.5%. The income approach is also relevant when an inherited family home was rented out at the date of death.
Cost approach (méthode de la valeur intrinsèque)
Used for unusual properties — historic buildings, custom-built villas, properties with no comparable sales — and as a cross-check for the other two methods. The valuer calculates the land value (based on the prix du terrain in that commune) plus the depreciated reconstruction cost of the building.
A professional report cross-checks at least two methods and explains discrepancies. A 5–10% spread between the comparison and income approaches is normal; a 30% spread is a red flag that requires investigation.
Documents you need
Gathering documentation in advance saves time and money. The valuer will request:
- The most recent notarial deed (acte notarié)
- The cadastral extract (extrait cadastral)
- Construction or renovation plans, if available
- The energy performance certificate (passeport énergétique)
- Recent renovation invoices — these can support a higher valuation
- The last property tax notice (impôt foncier)
- For rental properties: current lease agreements
- The death certificate and a copy of the will or acte de notoriété
Don't panic if some documents are missing. A professional valuer can retrieve cadastral data directly and reconstruct missing technical details from a site visit.
Common pitfalls and how to avoid them
Underdeclaring to save tax. The single most expensive mistake. The Administration compares declared values against its own transaction database; significant deviations trigger an adjustment notice with a 10% penalty plus interest.
Using the fiscal value (valeur unitaire). This is a historical reference figure held by the tax authorities, often dating to the 1940s and indexed only sporadically. It bears no relationship to current market value and must never be used in an inheritance declaration.
Forgetting deductible costs. Notarial fees, registration duties, mortgage discharge costs, and even certain renovation expenses incurred during the estate administration can be deducted from the gross estate. Document them carefully.
Ignoring co-ownership complications. If the deceased owned the property jointly with a surviving spouse under the régime de la communauté, only half of the property enters the succession. Get the matrimonial regime confirmed by the notary before commissioning a valuation.
A practical example
Consider an inherited two-bedroom apartment in Howald: 95 m², built 1998, energy class C, with a balcony and a private parking space. A purely surface-based estimate using commune-average pricing might suggest €820,000. A professional valuation, however, will:
- Identify three comparable sales in the same building or street, completed within the last 12 months
- Adjust for surface differences (€/m² method), balcony, parking, floor level, and energy class
- Cross-check with a rental yield: at €2,400/month achievable rent and a 3.6% yield, the income approach suggests €800,000
- Reconcile the two methods and arrive at a defensible market value of, say, €790,000
That €30,000 difference matters. At a 6% inheritance tax bracket (siblings) it represents €1,800 in immediate tax savings; at the 15% bracket (non-relatives), €4,500.
Next steps
If you have inherited property in Luxembourg and need a defensible valuation for the déclaration de succession, the process typically takes 3 to 5 working days. Reach out via the contact form or call directly. The first consultation is free and non-binding.