3 buildings max rule.

[Oropher]

On Zion and maybe across all the worlds in the universal game, the maximum number of building you can build is 3. But can you buy more building from players and therefore own more than 3 buildings?

[Disarray]

fraid not, you can only own the maximum amount of buildings that the world owner has sets, no matter how you have managed to get them: (Rent, Buy etc)

[Magicfinger]

...and maybe across all the worlds in the universal game

The number of buildings that can be owned is determined by the world owner to fit in with their plan for the world.