-
Presumably the safe way to do things would be to ask the vendors if anyone objects to them using the service street, them should I try to buy the place, make it clear that any offer is based on the assumption that some kind of right to use (through use as you say or otherwise) is in place, then make sure the solicitors do their job in determining this.
Worth a try, if the vehicular access to the rear garden is important to you. Indemnity insurance would also be a possibility - I suspect that ownership of the access road may well be something lost in the mists of time.
Presumably the safe way to do things would be to ask the vendors if anyone objects to them using the service street, them should I try to buy the place, make it clear that any offer is based on the assumption that some kind of right to use (through use as you say or otherwise) is in place, then make sure the solicitors do their job in determining this.
The GIS map is interesting as it highlights the weird rear access arrangements some of the houses have around the area. Seems to be a common thing in North Ealing.
http://maps.ealing.gov.uk/Webreports/Highways/Adoptedroads.html
You can see that the service road gives access to rear access to several houses on that street.