Thanks for your enquiry.
To enable me to assist you fully, I really could do with knowing what it says in your Lease about the common parts. Are you able to let me have the wording please?
Apologies for the delay in replying.
On that basis, your neighbour should certainly not be storing anything in the communal hallway.
As regards the decorating, it is really up to you both to agree on what and how the communal areas are decorated, unless a third party owns the Freehold, in which case you would ust need their consent before starting the work.
I hope this answers your question, and if so, I would be grateful if you could leave positive feedback.
It depends on who owns the Freehold to the common parts. Do you both own a share in the Freehold or is it owned by an independent person?