Legal restrictions

Here's the link to Italy's official gazette: https://www.gazzettaufficiale.it/eli/id/2004/12/31/004G0346/sg

Article 8 regulates distances: "Apiaries must be placed no less than ten metres from public roads and no less than five metres from the boundaries of public or private properties. Compliance with the distances in the first paragraph is not mandatory if there is a height difference of at least two metres between the apiary and the places mentioned, or if there are continuous walls, hedges or other barriers suitable to prevent bees from passing through. Such barriers must be at least two metres high. Agreements between the parties concerned remain valid regardless."

The chimney's exit is beyond the required 2 metres; in any case, it's a good idea to check whether your municipality has stricter rules by calling the local veterinary health authority.