I would suggest that if any "rights" are in force then the builder of the extension has frittered away their position to use the driveway of the one without an extension. If a shared access agreement is in place it will be for a narrow drive covenant, then it would only cover the strip that would be needed to allow a vehicle to pass... hence why the neighbour has left a strip to the left of his building. However that would only apply to that strip, not the rest of the driveway. Basically he has blocked his own drive and would enjoy no "rights" to use the rest of the drive on the neighbours side.
For clarity on rights read this :
1. Express rights which are written into the property title deeds having been created and granted by previous owners which then bind the subsequent owners. These rights are known as ‘running with the land’ and the rights are automatically inherited by the new owners of the property as they change hands over the years.
2. Prescriptive rights. They can be created by simply exercising a right of way over someone’s land continuously for a period of at least 20 years without the owner’s permission or consent. If you can evidence this continuous usage, you can apply to have the right registered against both property titles.
3. Consents or permissions. They are informal arrangements agreed between both parties which can be terminated at any time by the owner and cannot be passed onto a new owner of your property.
Consult the deeds.. you can do it online, the title plan will be clearly marked with any registered shared access agreement, normally in yellow hatch.
For clarity on rights read this :
1. Express rights which are written into the property title deeds having been created and granted by previous owners which then bind the subsequent owners. These rights are known as ‘running with the land’ and the rights are automatically inherited by the new owners of the property as they change hands over the years.
2. Prescriptive rights. They can be created by simply exercising a right of way over someone’s land continuously for a period of at least 20 years without the owner’s permission or consent. If you can evidence this continuous usage, you can apply to have the right registered against both property titles.
3. Consents or permissions. They are informal arrangements agreed between both parties which can be terminated at any time by the owner and cannot be passed onto a new owner of your property.
Consult the deeds.. you can do it online, the title plan will be clearly marked with any registered shared access agreement, normally in yellow hatch.