Covenants or other restrictions in the title to your property or conditions in the lease may require you to get someone else's agreement before carrying out some kinds of work to your property.
This may be the case even if you do not need to apply for planning permission.
You can check this yourself or consult a lawyer. You may also find that some properties enjoy historic rights. The council has no involvement in checking or enforcing your private rights such as a "right to light".