A party wall is a wall, boundary, or outbuilding that you share with another household, such as a semi-detached, terraced house and can affect detached properties if you share a garden wall or invisible boundary line.
For alterations, you need to gain written permission from the affected third parties so you can do the work, as it can affect them. Most of the time people are nice and let you get on with the work, but if they refuse, a party wall surveyor will need to be brought on board, if you don’t have one already, to put together a legal agreement together and better explain the situation to your neighbours.Â