It is assumed as a starting point that owners should know the boundaries of the properties that they own. In practice this is often not the case, especially if the boundary is not marked or defined on the ground. Even when a boundary is marked by a wall it Is not always clear if the wall belongs to one owner or the other or if it lies astride the boundary line (line of junction) making it a Party Wall. It is of the utmost importance that designers and Party Wall Surveyors know where a boundary line is. The best definition is by a Title document, for example, a Land Registry plan or register entry or a property deed. It can sometimes be necessary to look at documents relating to both adjoining properties to see if either define a boundary or state the ownership of a wall. Unfortunately, title document are often silent or do not contain adequate detail.
If a Party Wall Award is made based on mistaken information concerning a boundary then the Award will be void and the rights given will not be applicable even if the Award has been agreed by surveyors appointed by both owners and even if the Award has not been appealed.
If works are commenced in accordance with a Party Wall Award which is based on incorrect information or assumptions these works may be arrested by an injunction.
It is the responsibility of owners to determine the boundary of their property and to inform their designers and Party Wall Surveyors. In the absence of clarity a Party Wall Surveyor can offer advice on how to proceed and how to minimise the risk of an injunction.
Watson Woods Partnership
In the absence of clear evidence the possible boundary can be judged by:-
A. Evidence on the ground: Alignment of features or details on a wall that suggest ownership. Some such details are compelling evidence. For example plates or stone tablets set into walls that state the ownership of a wall or the position of a boundary.
B. Historic map analysis. This can sometimes shed light on how a property has evolved and give clue as to ownership.Site evidence and historic map analysis are at best guidance and are rarely conclusive.
If a boundary is not clearly defined by a title document it should be agreed between the owners before an Award is made and certainly before any works to or along a boundary are carried out. Any agreement should be documented.