Hi, many thanks for your reply
the drainage from the garage roof goes to the far end of the garage where it goes into a fall pipe on next doors property.
The Downpipe you can see is from a valley between roofs on our house, there is also a waste pipe that comes from our bathroom which comes out over the neighbours property down the side of the house and back into our property, none of this is in the deeds.
we move here last year and the neighbours moved in 3 years ago
regards