How do you claim space in garden from other tenants

I have lived in my home for 13yrs, always used the outdoor sheds (old coal or toilet sheds) as my own. I restored them and reroofed them in 2014. No other garden has access to them. How do I get them added to my property deeds please?

Alexandra - if you mean claiming land then see PGs 4 and 5 and seek legal advice https://www.gov.uk/government/collections/land-registration-practice-guides

I note you also refer to 'tenants' so if you are in a freehold/leasehold scenario and want to have the space added to your lease then that would be a different matter and one for your landlord/freeholder as well as legal advice