ᐅ Sealing and Insulating the Basement Exterior Wall to the Facade

Hello everyone,
During the reconstruction of my terrace, I encountered some surprises and had to completely redo the waterproofing of the exterior basement wall in this area. Additionally, I decided to install 10mm XPS boards. The house will most likely receive full exterior insulation, including the basement walls, in the future, and I want to avoid having to tear up the newly built terrace again for that.

I am currently facing the challenge of waterproofing and insulating the basement exterior wall in the plinth area. I am somewhat unsure how to proceed here.

The problem is that the basement exterior wall in the terrace area is wider than the wall of the façade above it. This creates a step that now needs to be professionally waterproofed and insulated. This “step” is sheltered from the weather under a balcony, so in recent years there hasn’t been any real moisture problem there despite the lack of waterproofing. The last row of terrace tiles in the old setup was glued directly onto this “step.” I am not sure if this step also forms the basement ceiling at the same time. In any case, it was quite a thermal bridge.

How can I properly waterproof and insulate this “step” area?
How should the two-layer dimple membrane be installed in this area and where should it be led upwards?

Another issue near the terrace door is that there is a height restriction.

The house was built in 1962 and mostly made of hollow concrete blocks, including the basement. Attached are some pictures.

I look forward to your suggestions.

Best regards,
Benedikt