Maximum Number of Buildings: The maximum number of structures you can build on a planet depends on the population of the planet.
Maximum_mines = Colonist_clans ...if Colonist_clans < 200 Round(200 + Sqrt(Colonist_clans - 200)) ...if Colonist_clans ≥ 200 Maximum_factories = Colonist_clans ...if Colonist_clans < 100 Round(100 + Sqrt(Colonist_clans - 100)) ...if Colonist_clans ≥ 100 Maximum_defense_posts = Colonist_clans ...if Colonist_clans < 50 Round(50 + Sqrt(Colonist_clans - 50)) ...if Colonist_clans ≥ 50
Note that you need not permanently fulfill these conditions. You can build factories and beam off clans to a ship. PHost will consider this possibility when checking turn files. However, buildings over the limit as determined from the planetary population will decay at a rate of StructureDecayPerTurn.