ᐅ Drainage Along Exterior Walls – Any Experiences?

Good evening,

I am new here, and we are currently planning to build a single-family house. In the basement, we want to include a sauna area with a shower and whirlpool.
Since the new development area has relatively limited planning, it will probably not be possible for us to have drainage underneath the slab because we would no longer be able to maintain the necessary slope for the wastewater pipe.
If I calculate from the sewer invert with a 2% slope towards the building, my wastewater pipe would exit about 5 cm (2 inches) below the raw floor level. We would prefer to avoid a lifting system due to its annual maintenance requirements and want to use a backwater valve only.

Now to my question:
Does anyone have experience with drainage through the basement exterior wall in combination with a backwater valve?

Thank you in advance for your support!

Daniel