Thereof, can I stain my side of Neighbours fence?
If it's on their side of the property line, even by one inch, it's their property. And if they paid for it to be built, it's their property. You can't paint the fence any more than you can paint their house or their car because you don't like looking at it.
Subsequently, question is, which side of the fence do you own? Also, there's no set rule about whether you own the fence on the right or on the left-hand side of your house. You may be able to get this information from the conveyance deed, where there could be an already established boundary agreement regarding which fence side you are responsible for.
Also asked, is it OK to stain one side of a fence?
Wood stained on only one side will certainly degrade on the other. And, there is certainly individual interest in appearance that works with each home.
Can Neighbours attach things to my fence?
Both neighbours may attach screens or trellises to a fence, provided they do not damage it.
