Structure in garden attached to neighbours fence posts

[AGrownManMadeWager]

Can someone in Scotland build a wood store (shorter than height of fence) and attach it to the fence posts in their garden if that boundary is the neighbours side?

Is it your fence or not?

It's not our scenario.
The fence is owned by neighbour A, neighbour B wants to build a wood store which would be secured against the fence posts, fence posts are on neighbour Bs property.

If was neighbour A I would remove the fence at some point...

Has neighbour B discussed it with neigbour A? Can they not site it away from a fence they dont own?

Whats the actual legal situation though? It's a scenario a few of us are discussing about one of our ex neighbours and no one can agree where the law would stand.
Thought I'd ask on here.

It is notoriously difficult to say with accuracy where a boundary on a plan is on the ground. If the fence belongs to A then regardless of where B things the fenceposts are the wood store should be a freestanding separate structure. This avoids attaching it to A's property which could potentially be criminal damage and fences are to fence an area in, not to attach something like a wood store to at risk of being damaged by the weight of what is attached.