Place new terrace slabs on old washed concrete slabs

Hello everyone,
slowly we are getting to the garden/terrace design. At the moment, we have a terrace made of old exposed aggregate concrete slabs. The terrace has been there for about 40 years and will definitely be redone. Since the new terrace should be a bit higher and the current slope no longer fits, the idea was to lay the new slabs on a bed of gravel on top of the old exposed aggregate concrete slabs. Possibly, 1-2 rows of concrete slabs will be removed and filled with gravel. Is this generally possible? I suppose it would be better to remove all slabs and put gravel in, right? How thick can the gravel layer be to lay the slabs? I estimate we would probably have about 8-10 cm near the house wall. Would that be too much or could you otherwise set the slabs directly in gravel? Thanks

slowly it's time to design the garden/terrace. At the moment we have a terrace made of old wash concrete slabs. The terrace has been there for about 40 years and will definitely be redone. Since the new terrace will be a bit higher

That calls for a wooden terrace.

It is actually not supposed to be
[Betonplatten] 5.5 cm thick are supposed to go on it. Hence my question.

If it fits in the space, leave the old slabs underneath and simply lay the new ones on top. On gravel with the appropriate slope, as you wrote.

If there is enough space, leave the old slabs underneath and simply lay the new ones on top. On gravel with the appropriate slope, as you described.

That's exactly what I wanted to hear Thank you

If, however, the water does not drain then...