Split level vs retaining wall

I have excavated ready for garage slab just needing final detail.
I am trying to understand the theory in building options what would be different as it slopes from front (zero height) to back ~1.2m high.
I was thinking of pouring the slab and have starter bars coming out and besser block upto 1 m high core filling it then waterproof behind and backfill.
Or
Retain separately with a gap between the garage and back wall. The side walls can also become part of the structure or I have approx 300mm gap between retaining walls on each side.
Or
Build it as a split level as behind it at the 1.2 m end I need to shape/ level anyway, by doing this way I assume it prevents the retaining wall from " topping over and eliminate a giant base footing or base thickened raft slab is this correct?
At the back I can put stairs in after.
An engineer didn't sort of understand what I wanted.
As 2870 has a picture of a wall 200 mm thick but it doesn't mention any backfill against it just waterproofing.Detail for footing and single leaf reinforced masonry wall combo. Which is good for single storey height.


Sent from my iPhone 4s using Tapatalk


Read the full thread at RenovateForum.com...