ᐅ Patio Tiles – Are Base Tiles Necessary?

Hello. Our terrace will be tiled. Now we are wondering if base tiles are absolutely necessary for the outdoor terrace? Our house has external polystyrene insulation (ETICS). We would prefer not to use base tiles. But how is the connection to the house made then? Just with a silicone expansion joint?
How have you solved this? We look forward to your answers.
Best regards,
Peter