What is common wall?

Common wall means:-

a) A wall built on land belonging to adjoining owners and the wall being the joint property of both the owners.

b) If two adjoining owners build dividing walls on their property, they are not common walls and no part of the footings of either wall shall project on to the land of the adjoining owner except by legal agreement between the owners.

c) Any such ‘common’ or ‘dividing’ wall shall be considered for the purpose of these bye-laws, as being equivalent to an external wall as far as the thickness and height are concerned.