Hi Zoran,
There is not the same leasehold/freehold system here as in the UK when buying a flat in Vienna. One slight quirk is that you buy effectively the insides of the walls of the flat in a house made up of multiple dwellings, so if you wanted to add a balcony, you need the house owner and the other owners agreement to do so. Once of the biggest issues on new and old places will be the Reparaturfond (repair/maintenance fund) which covers the communal parts of the building. I regularly ended up having to top up ours. Also always worth checking how lift use is calculated. Similar Betriebskosten have a coefficient that increases by floor…