Boundary wall and Waterproofing

Hi, My neighbour is doing an extension and has built his brick garage on the boundary between our properties. He decided ( on his own ) to paint a black waterproofing substance along the wall, covering 0-50cm above ground level on my side. This is unsightly as the wall is 15m long and faces my side yard. What is the law / normal practice when it comes to how high a neighbour can waterproof on my side of the boundary?
Thanks

Technically speaking it's his wall, on his property so he is entitled to treat it as is necessary.
Zero lot walls are often a bone of contention as one person owns the wall however it faces the neighbour.
You could speak to them and ask if you could paint it a uniform colour over the waterproofing. The other option is to put up a fence on your property to hide their wall.
Just don't do anything or attach anything without permission as it doesn't belong to you.

Thanks for the help chippy.

Question.
If both parties agreed that the wall had to be brick as part of the planning permit, can he still paint 50cm of water membrane up the wall above the ground?

Appreciate the help

Clarification. When I said the wall had to be brick, I meant the wall had to be exposed recycled brick.

just talk to them, tell them it is unsightly and ask them for a solution. Any reasonable person would render it for you or do something similar. If they give you trouble build a 60cm deep garden bed or get your kids to use it for soccer practice.

You could also speak to their builder, often they are more reasonable as they do this all the time and are less emotional than the owner.