A plan is the only element of a listing that cannot be shot on a wide-angle lens. For a buyer it does a second job: it shows what can be changed, what cannot, and where the boundary between your property and the building's actually runs.
First, normalise the surface
Luxembourg listings quote surface in several ways, and comparability depends on stripping it back. Total surface, habitable surface, terraces, balconies, cellars and parking lots may all appear in one headline number. A property advertised at 110 m² including a 15 m² terrace and a 10 m² cave is an 85 m² apartment.
Check the rooms drawn against the figure quoted. Then look at how much of the habitable surface is circulation: a long internal corridor serving four rooms can absorb eight or nine square metres that appear in the total and serve nobody. Two apartments of identical surface, one with a central hall and one with rooms opening off a living space, are not equivalent purchases.
For a buyer this matters twice over, because price per square metre is the metric everyone uses to compare and it is only meaningful once the denominators match.
Read the walls, not the rooms
Drawn wall thickness distinguishes structural elements from partitions, and for a buyer that distinction is the map of what can be altered.
A partition can usually come out with the landlord's equivalent here being nobody, since you own the private part. A structural wall cannot, and in a copropriété under the amended law of 16 May 1975 the structure is a common part. Work touching it is not a matter of your preference: private installation work is subject to a vote at the general assembly, and improvement works require an absolute majority of all millièmes.
So the open-plan layout you can see in your head on the drive home is either a straightforward interior job or a proposal you will have to put to your neighbours. Establishing which before the offer changes what the property is worth to you.
Services, which decide the cost of any change
Look at where the kitchen and bathroom sit relative to each other and to the neighbouring lots. That tells you where the risers run.
Moving a bathroom away from an existing riser is among the most expensive interior changes available, because drainage needs fall and the fall has to go somewhere. A plan showing a kitchen and bathroom back to back is a plan with concentrated services and lower alteration costs; one with them at opposite ends is the reverse.
The same reading identifies acoustic risk. A bedroom sharing a wall with the building's water riser, or backing onto the lift shaft, will hear both. In converted townhouses with timber floors and little acoustic separation, which make up a large share of the stock in Limpertsberg, Belair and the Gare district, this is worth confirming in person by standing silently in the room for thirty seconds.
The measurements to take before the second viewing
- Longest uninterrupted wall in each bedroom, which decides whether standard storage fits or joinery is required.
- Living room wall for seating, about 2.2 metres plus clearance. Count the doors opening into the room; each removes a wall.
- Door swings. Every door is drawn with its arc, and overlapping arcs or a door opening into the only usable wall are the most reliable early warning of an awkward room.
- Lift car and stairwell. Internal dimensions, the diagonal of the lift door, and the narrowest point of the stairs, which determine what furniture can physically arrive and whether a hoist and possibly a commune permit are needed.
- Window head height and room depth. Useful daylight reaches roughly two to two and a half times the window head height into a room, so a deep room with a low window head will be dark at the far end regardless of orientation.
What the plan does not show, and must be asked
Ceiling height is never on a plan and varies enormously in Luxembourg, from three metres in a nineteenth-century conversion to considerably less in a 1970s block. It changes how a given floor area feels more than almost any other variable.
Orientation is frequently omitted. Check it with a compass at the viewing rather than accepting a stated answer, and look at what obstructs the sky, because the city is a plateau cut by the Alzette and Pétrusse valleys and a south-facing courtyard flat on a low floor can receive very little winter sun.
And the plan says nothing about the acte de base, which defines what is private and what is common. Ask for it. A terrace or garden that appears on the plan as yours may in fact be a right of exclusive enjoyment over common property, which changes what you may build, plant or store there.
Three questions we are asked
Is a 3D visualisation useful? For layout only. Rendered furniture is routinely drawn undersized, which is why rooms in a render appear more generous than the same rooms in a photograph.
What if no plan exists? Ask the seller or the syndic, since the acte de base will contain the lot description. Failing that, measure and sketch it yourself at the second viewing; it is a better use of the slot than a further look at the kitchen.
Should I plan alterations before completion? You can plan them. Do not budget on them until you know which are interior work and which require the assembly's authorisation, because the two have completely different timelines and probabilities.
Turning the plan into a viewing agenda
The purpose of reading a plan carefully is to convert a twenty-minute visit from a general impression into a short list of things to verify. Arrive with four marked items rather than a vague intention to look around.
A typical list: confirm the ceiling height, which no plan shows; establish which walls are structural, since that is the boundary between an interior job and a proposal requiring the assembly's authorisation; locate the risers by standing in the room nearest them and staying silent for thirty seconds; and measure the lift car and the narrowest point of the stairwell, which determine what can physically be delivered.
Two checks belong outside the apartment. Ask to be taken to the cave rather than told it exists, measure it, and look at the base of the walls for salt bloom or a tide mark. And walk from the building entrance to the nearest stop, timed by you. Public transport in Luxembourg is free nationwide, so the variables are minutes, frequency and gradient, and the city's plateau-and-valley topography means a short route on a map can involve a lift or a serious climb.
Three questions we are asked
Can I trust the surface stated in the listing? Treat it as a starting point and check it against the drawn rooms. The authoritative description of the lot is in the acte de base, which is worth requesting before an offer rather than reading at the deed.
Does a terrace count as living space? Not as habitable surface, and in many buildings it is a right of exclusive enjoyment over common property rather than a private part. That distinction governs what you may build, plant or store there, and it is set out in the acte de base and the règlement de copropriété.
How much should a plan influence the offer? Enough to separate what is fixed from what is changeable. An awkward layout that can be resolved with interior work is a negotiating point; an awkward layout that would require the general assembly's authorisation is a permanent characteristic of the property.
Editorial note: Acquisition costs, tax credits, lending limits and co-ownership obligations in Luxembourg change, and every transaction differs. This article is a framework, not advice on a specific purchase. Confirm the current position with your notary, your bank, the Administration de l’enregistrement, des domaines et de la TVA, guichet.lu or a qualified adviser before relying on it.