Penetration Existing Slab?

[J189]

Below is the sketch of an extension on the existing first floor. new steel columns will be used as shown and go from footing through the existing slab and support multiple new floor above.
The details of the existing floor is unknown (thickness roughly from 200-300mm). What do you suggest for the detail of the penetration without affecting the existing concrete slab?
Thank you.

 

[Settingsun]

No sketch but what is this structure with multiple floors but no structural engineer?