We have a garage in the side-return of our house. It's pretty basic in design, with the roof attached to the wall of our house and the wall/fence boundary with a neighbour, supported by some brick-work beneath (see attached). We have planning permission to build an extension in its place at some point, but at the moment the work is some way off as we need to and save up for the party wall agreement and build costs.
Unfortunately we are probably going to have to remove the garage in the meantime because the roof is made of asbestos which is showing signs it might break, its old wooden doors to the street are rotting and are no longer secure and the structure is causing damp issues in our house where the garage joins to it.
The opposite side of the garage runs along the bottom of a neighbour's garden. That shared boundary consists of an existing 1.5m high solid brick wall with sturdy wooden fencing on top of it (combined height of 2.2m), followed by a further continuous length of sturdy fence of 2.2m height for the remaining length of the garage.
The neighbour says the brick wall is theirs, the fencing ours.
We want to remove the garage roof, supports and doors-to-street (so essentially removing the garage) soon because of the asbestos and before it does more damp damage to the house. Our plan would be to construct a wall along where the back of the garage currently is to seal off our garden, and to use space where the garage was for off-street parking.
We would leave the 2.2m high boundary wall and fencing with the neighbour as it is, as it is not part of the garage structure.
Regardless, our neighbour says that removing our garage will leave the bottom of their property exposed - and that we will need to put something up in the to protect their property. This is even though obviously there would still be the existing wall and fencing in place.
Who needs to do what here?
Is it actually their responsibility to increase the length and height of their own wall if they wish to bolster their security? Or are we obliged to replace the fencing to their satisfaction because we are removing the garage despite what's there being sturdy and solid?