Where can one find out the annual costs for owning

Your IMU (property tax) is calculated according to the rateable value of the property and the comune you live in.  The TARI (rubbish tax) is calculated on hte basis of the square metrage of the property and the comune sets the rate.

Plus charges for gas, water  and electrics - even when the place is empty (Standing Charges). Plus annual  gas boiler service charge (mandatory).