you may not need planing as its established, however please make a descreet enquiry to the council.
Solicitor will sort out ur deeds, however if it were me, i'd try to mortgage the lot on one deed, unless your thinking of seling then you will need to split deeds, top flat leashold. bottom can be freehold.
A tip for you, make sure you correctly split all the utility's as this will be better in the long run. i paid £850 for new electricity supply and £400 for new gas connection. If you need help then please feel free to call me...
Alex M
www.oakhillmortgages.co.uk