Almost everything a cat needs from an apartment is vertical, and almost everything an apartment can offer is decided by what the building permits. The two meet in a short list of reversible changes.
Start from what the building allows
In a copropriété, the facade, the structure and the common parts are governed by the règlement de copropriété and the acte de base, and most leases bind the tenant to respect them.
The items that matter here are the ones people plan first: netting or mesh on a balcony, anything fixed to a railing, and anything visible from outside. All of those touch the facade, which is almost always common property even where a balcony is for your exclusive use, and they frequently require the general assembly's authorisation.
Ask for both documents before signing and get any permission in writing. A landlord cannot grant rights the co-ownership has not granted them.
Vertical space, which costs no floor area
Luxembourg apartments are planned efficiently on floor area and thin on internal storage. That makes vertical solutions the right answer twice over.
Three positions are consistently unused in this housing stock. Above door height, where a shelf run at around two metres is invisible in use. The corridor, at shallow depth, provided it does not become the narrowest point. And deep window reveals in older converted buildings, which take a board and become both a shelf and the best-lit position in the apartment.
Measure the longest uninterrupted wall in each room and the ceiling height, which ranges from around three metres in a nineteenth-century conversion to considerably less in a 1970s block. That number decides how much of the wall is usable above head height.
Fixing, and how to avoid needing to
In a rental, read the lease before drilling and photograph each wall before and after. Filling and touching in a fixing costs a few euros before an exit inspection and appears at contractor rates afterwards, against a rental guarantee capped at two months' rent excluding charges.
In an owned apartment, anything touching a load-bearing element or the building's common systems requires consent and frequently the general assembly's authorisation, since the structure is a common part.
Freestanding tall units that lean or stand independently avoid the question entirely and can be weighted low for stability. In newer Kirchberg and Cloche d'Or stock the walls are frequently concrete, which holds weight well and needs the right fixings.
Materials that survive and still look considered
Three choices carry most of the weight and none of them reads as pet equipment.
Tightly woven flat-weave rugs rather than long pile. They survive claws better, lift for cleaning, and in a building with timber floors they reduce what carries to the neighbours below, which matters because complaints run from the syndic to the owner and then to the tenant.
Removable washable covers on upholstery rather than fixed. A room where every surface is fragile becomes a room that is guarded rather than used.
Matt rather than glossy surfaces. Under Luxembourg's flat winter light gloss reflects the ceiling as an even sheen and shows every mark, so the durable choice and the good-looking one are the same choice here.
Light and warmth, which decide where the cat actually goes
The sun sets before half past four in late December and a large share of days between November and February are overcast. In that period the warm, lit positions in an apartment are few and they are where an animal will be regardless of where you put anything.
Check the compass bearing of each room and the angle to whatever faces the window. Above roughly forty-five degrees, a south-facing room on a low floor receives very little direct winter sun. Note also where the radiators sit, since a sofa or a shelf against one blocks the heat during a heating season running roughly October to April.
Working with those positions rather than against them removes most of the friction of an apartment shared with an animal.
Ventilation, which is a real constraint
A well-sealed apartment heated all evening and not ventilated develops condensation, and the visible signal is a dark bloom in the corners of external walls and around window reveals.
The routine that works is short and forceful rather than continuous: windows opened wide for a few minutes twice a day rather than one left ajar. With an animal in the apartment, tilt-and-turn windows left open unattended are the risk people underestimate, and restrictors or freestanding barriers inside the room are the answer rather than anything fixed to the frame, which in most buildings is common property.
Litter, storage and the cave
The practical requirement is a ventilated position out of the circulation route and away from where food is prepared, which in a compact apartment means planning it rather than improvising it.
Bulk supplies belong in the cave. Ask to be taken to it, measure the floor area and the height separately, and check the base of the walls for salt bloom or a tide mark, since a damp cellar stores nothing made of cardboard or paper.
Three questions we are asked
Can I fit balcony netting? Ask in writing, because it is normally fixed to a railing or facade that is common property. Freestanding barriers inside the balcony are a different question.
What about scratching on door frames? Record every existing mark on frames, skirtings and doors at the entry inventory, since those are the surfaces examined at the exit inspection.
Does the building need to permit cats? Building rules commonly address animals in general terms. Read the règlement rather than assuming the restriction applies only to dogs.
Three questions we are asked
Do I need to declare a cat to the commune? The declaration, insurance and tax obligations under the amended law of 9 May 2008 concern dogs. Building rules may still restrict other animals, so read the règlement de copropriété rather than assuming.
What about the common parts? Corridors, landings and stairwells are common property and most buildings restrict what may be kept or done there. An animal in a common area is a matter for the building rules rather than for the lease.
Which single change does most? A tightly woven flat-weave rug. It handles claws, lifts for cleaning, reduces what carries to the neighbours below, and reads as furnishing rather than as pet equipment.
What to record at a viewing
Five things, none of which appears in a listing. The longest uninterrupted wall in each room and the ceiling height, which together decide how much vertical space is available. The window type, since tilt-and-turn openings left unattended are the risk people underestimate. The compass bearing and the angle to whatever faces each window, which determines where the warm lit positions will be from October. Whether the building rules address animals and what right attaches to any balcony. And the cave, measured rather than described, with the base of the walls checked for damp.
Editorial note: Dog law in Luxembourg is set by the amended law of 9 May 2008. The annual dog tax, its amount and the declaration procedure are communal and therefore vary. Rules on animals inside a building are set by each copropriété. Verify with guichet.lu, your commune, your vet and your lease or règlement de copropriété before relying on any of the above.