Semi – Demolish?

Hi

I am thinking of buying an inner semi – probably on 200-250sqm of land. It will be pretty old and given the high cost of renovation, it looks to make more sense to demolish and rebuild.

Now, obviously there is a responsibility to maintain the common wall which is ok and I am assuming that the block is sufficiently narrow that I will need to either build right up to or use the common wall but everything else is completely new.

Does anyone have any experience in such rebuilding? or particular builders or websites that do it?

Are my assumptions around cost (even with the common infrastructure) correct? or am I missing something?

Cheers!