What happens if the party wall is not strong enough for heightening in terms of cost and responsibility?
If the party wall is not strong enough to withstand the heightening, the co-owner who wants to increase its height must bear the entire cost of rebuilding the entire wall. Additionally, any necessary thickening should be done on their side of the wall as much as possible. The rebuilt wall will continue to be co-owned, except for the heightened part, and the neighbor who performed the heightening will not be entitled to any compensation.