Block paving - retaining wall

[ScoobyDoo]

Hello all.
My drive is built on a slight slope adjacent to my neighbours. However at the top end if the drive there is a 20-30 cm drop to my neighbours drive. Currently both our drives are concrete drives and so my drive is a concrete slab next to his concrerete drive with no retaining wall necessary.
I want to replaced my existing drive with block paving but this drop between our drives worries me.
I now I will need a retaining wall built if I am to have a block paved drive but...
1) How deep do the footings need to be opn the wall? I would like the wall to raise about 2 brick courses above my drive height to act as the boundary.
2) What should the sub-base consist of? Would a concrete base be needed before the usual sand etc becuase the excavated area will be so deep?
3) When my neighbour replaces his drive, next year, what is the risk of damage to the wall seeing as the wall will be the boundary and his drive touches it?

I hope this questions make sense, sorry if is a run of the mill situation but I'm a born worrier!

[Tony McC]

1 - If you're dead set on using brickwork as a retainer, then the foundations need to be lower than any excavation work that might be carried out on the neighbouring property next year, which, for arguments sake, means ensuring the top of any concrete footing is at least 300mm below pavement level.

2 - one the wall or other retainer structure is in place, use granular sub-base to build up levels as required, compacting in layers not more than 150mm thick.

3 - Depends on how good is the contractor. As long as the footing is deep enough, and due care and attention is used, there's no reason at all for there to be any damage to the retainer wall.

[ScoobyDoo]

Thanks very much for the prompt reply.

Now I know what needs to be done I'll feel a lot happier when asking for quotes.

Thanks again Tony. Much appreciated.