Answer

Construction work, including renovations or extensions, may likely have some impact on a Party Wall structure. A wall is considered a party wall structure if it meets either of the following two conditions:

1. The wall in question stands astride a boundary of land belonging to two or more different owners; this means that approximately half of the given wall is situated on land belonging to at least two different parties. The party wall may be part of a single building, it may separate two or more buildings, or it could serve as a party fence wall separating two different properties.
2. A wall is also deemed to be a party wall structure when it stands entirely on a single owners property but it is used by two or more owners to separate their buildings. A good example is where one owner built a wall, but another owner has built up against it without constructing their own private wall.

If you are the adjoining owner and are perhaps building on or astride the boundary wall this may affect your property when you decide to sell or build your own extension at a later stage.