One Sunday supper, over red wine and meatballs, my Italian mother-in-law announced that her nephew—our cousin, one of the youngest in a field of 13—was getting married. The destination? Sicily . We sat eight-deep around her steadfast dining table on Long Island, which had shepherded us through Feasts of the Seven Fishes, Easter celebrations, and countless birthdays, and it was decided right there that we would need a house—or rather, a compound—where we could all stay together and embrace the charms of their ancestral homeland.

We needed space. Lots of it. Enough to hold five adults, three children, and one communal dream of living like Sicilian locals.…