“If you are a homeowner in Switzerland, you have to pay income tax on what is known as its ‘rental value’. The rental value theoretically represents what you as owner would receive if you rented the property to someone else, i.e. what that tenant would pay you in rent. At the same time, you can deduct mortgage interest payments and other costs for the upkeep of the property from your taxable income.”
https://www.ch.ch/en/rental-value/
“If you are a homeowner in Switzerland, you have to pay income tax on what is known as its ‘rental value’. The rental value theoretically represents what you as owner would receive if you rented the property to someone else, i.e. what that tenant would pay you in rent. At the same time, you can deduct mortgage interest payments and other costs for the upkeep of the property from your taxable income.” https://www.ch.ch/en/rental-value/