The core mechanism is easy enough: a state extends the right to live there to non-citizens who place a qualifying amount in housing. The threshold is set very differently from country to country, and the authorities adjust it with limited notice.
One key point stands between residence and naturalisation. The permit allows you to live there, generally subject to renewal, while a passport generally takes a long period of residence. An agent's promise of nationality in return for a property for sale in northern greece deal is a warning sign.
Past the headline threshold, these schemes impose extra obligations. Typical examples involve a clean criminal record, medical insurance, proof of income and a required physical presence in the country each year. Missing any of these can jeopardise the permit regardless of the property.
Tax residency remains a different question altogether. Owning property does not by itself make you liable for nis real estate local income tax, but spending enough time in the country frequently does. Most jurisdictions use a day-count rule, and the consequences extend to income earned elsewhere.
A sensible approach is straightforward: buy property in sofia something you would be happy to own, with the permit as a secondary benefit. Programmes close sometimes at short notice, and an apartment bought only for paperwork proves difficult to let and difficult to sell.