The Swiss authorities online
Anyone who owns an apartment or house must declare it as an asset in their tax return and is liable to pay wealth tax on it.
All the cantons and communes levy a tax on the assets of private individuals. The wealth tax payable on real assets is based on its taxable value. The way in which this is calculated varies from canton to canton. In contrast to the position with property tax, proven debts reduce the taxable value of a property for the purposes of wealth tax.