May end up having to talk to surveyors and solicitors but interested if anyone else has come across this. I’m sympathetic to our neighbour because we used to live in a flat that had a terrace on top of the flat roof of the flat below. The flat roof was owned by all 3 flats in the building as share of freehold.
Where we are now, the lease shows that we own the flat roof, but our upstairs neighbour uses it as a terrace - in place before we bought. We had no objection as there is no noise or damage. Neighbour keen to formalise this arrangement as worried if we sold that new owners could change this. Can one sell a flat roof? But may not want to as need to access for repairs etc. Or move the roof to being shared ownership? Neighbour is prepared to pay costs, agree price etc. Or is it too complicated/unwise to sell part of property like this?