Can't get a mortgage due to site access

Has anyone ever been turned down for a mortgage for a self build due to the site being accessed by a shared right of way. Is there anyway around this? The shared right of way is a lane on my fathers land which leads to 3 sites. The bank won't offer a mortgage due to the fact that we don't own the lane but how can we when its used for 3 sites. Anyone ever in a similar situation??

Have you the right of way officially documented and registered by a solicitor?
That should satisfy the bank that you have iron-clad access to the house and can't be denied that access by any third party in the future.
However, what the bank may be being cautious on is not your right of way but their right of way should they need to repossess - this might be what's really on their mind - I recall something on this before - talk to your solicitor, what suggestion does he have