If you live in a house that is either terraced or semi-detached and you have shared walls with your neighbour then these walls are known as "party walls". An even simpler explanation is that a party wall is a single wall that belongs to different owners in different buildings. Only the part of the wall that is used by both properties is considered to be a party wall. The rest of it belongs to the person on whose land it stands on.

Before starting any work on your property you must get your neighbours agreement for any extensions, damp proofing works, structural alterations or internal refurbishment that might be required. If you don't you can be liable to legal action if the second party has not agreed for the work to be carried out.

The Party Wall Act etc 1996 is specific about who gets involved in a party wall notice. It states that the person who wants the work carried does not necessarily need to be the building occupier. The property could be leased, for example, in the centre of major cities which has a high percentage of office blocks not owned by the companies that occupy the space.

Typically a notice would be written in instances where:
-The owner of
the building wants to cut into a party wall, or take bearing from the wall.
- Where the building owner is looking to raise the height of the wall or to increase its width and cut off projection from it.
- Where they would be are looking to re-build the wall after demolishing it.
- Where the owner is looking to add protection of some kind, which would involve cutting into the adjoining owner's wall.

Distance notices:
There are special notices relating to excavation of a party and where this is carried out near neighbouring properties. This notice falls under Section 6 of The Party Wall Act etc 1996 and is typically known as the three and six metre notice. It is called this due to where the excavation takes place within three metres of an adjoining neighbour's structure where you are likely to go deeper than the adjoining neighbour's foundation. The six metre rule is where excavation takes place within six metres of an adjoining neighbour's building and you take a typical angle from the bottom of the adjoining neighbour's foundation. The building owner's excavation is probably going to go deeper than this.

Either way it's important that you get all the correct clearances before you begin any kind of home improvement to avoid any bad feeling or legal action.