If you are looking to carry out building works that are notifiable under the Party Wall etc. Act 1996 then you will need to serve party wall notices on your neighbours detailing what it is that you are looking to do to your home.
If your neighbour does not consent to the works, or consent subject to a schedule of condition report then a dissent will be triggered and a Party Wall Agreement will need to be in place before you can start the building operations.
A Party wall agreement is a legal document entered into by both parties when a neighbour does not consent to a notice that has been served upon them.
The Party Wall Agreement, or Party Wall Award as it is often referred to sets out the rights and obligations of the person carrying out the works has in relation to their neighbour.
As well as the usual Health and Safety requirements and ensuring the integrity and stability of the neighbours house is maintained throughout, the award can also include clauses that ensure the neighbour continues to have the full enjoyment of their home without nuissance.
Some typical clauses relate to noisy works, access onto the property, and ensuring the lands are never left open and that a fence or similar hoarding is in place at all times.
This all depends on how the loft is designed.
Typically speaking, a loft conversion will involve steel beams to support the new floor and roof. As a general rule of thumb there are usually two horizontal floor steels and one ridge beam which run the full width of the house and are slotted into pockets within the party wall.
It is the act of cutting into the party wall to form the pockets for the steels that mean you are legally obliged to serve a Party Wall notice in accordance with Section 2 of the Party Wall Act.
Other things to consider are cutting into the party wall to install lead flashing/waterproofing and rights of access onto your owners roof, for instance when tiling a dormer cheek that is built upto the boundary.
When deciding whether or not you require a party wall agreement for your extension there are two things to consider when trying to find out whether or not you need to serve notice on your neighbours.
The first is whether your extension is going all the way to the boundary.
If you are looking to build upto the boundary (but keeping the wall entirely on your own land) or whether you are intending to straddle the boundary with your new wall then in both of these instances you will need to serve notice on your neighbours in accordance with Section 1 of the Party Wall etc. Act 1996.
The other thing you need to consider is whether your new excavations (for the foundations) will be within 3 metres of your neighbours property and is likely to be to a greater depth that their foundations.
This includes all buildings including garages and outbuildings – not just your neighbours house.
If you are proposing to excavate within 3 metres of your neighbours building then you are required to serve a notice on your neighbour in accordance with Section 6 of The Party Wall etc. Act 1996.