Looking at the "Basic" D&D rules (red books), they don't cover characters up to the levels where they would be landowners etc. They only cover up to 3rd level.
The "Expert" D&D rulebook (blue books) covers characters up to 14th level, and includes sections on strongholds and land ownership. Once characters are 9th level, they can gain land but the narrative is definitely rooted in feudal concepts (fighters get land from a higher lord, and their realm is a barony etc)