I assume you own the house (rather than renting it). You need to look at your title deeds to see whether they show this area of land as belonging to you. If it is not shown then there is probably nothing you can do unless the neighbours are prepared to agree to you using it & no-one else (there must be someone who owns it, but it could be very difficult to find out for such a small area) objects.
If it is yours then your title deeds should show whether you have a right of way over any neighbouring land in order to access it. If no such right is shown then - as above - you must rely on neighbours goodwill.



