If you are planning to move to Italy and to stay for longer than 90 days, you might apply for the Elective Residency Visa.
The Elective Residency Visa can be released to those:
Being the owner of a property in Italy might facilitate you from obtaining the Elective Residence Visa, however this is not a standard requirement, since Italy does not have a Golden Visa program.
Consequently, if you are buying a property in Italy you will not easily obtain a residence permit. For this type of Visa, as above mentioned, there are further requirements to be fulfilled.
Since the elective residence visa sometimes refers to “wealthy people”, you need to prove that you have passive incomes to sustain your life in Italy even without working.
You can meet the requirement of passive income also through investments in residential properties.
Just be aware that the property needs to be a permanent residence, since this type of visa is only for people who have decided to reside in the Country permanently.