The Party Wall Act 1996 puts in place steps to safeguard the rights of those undertaking certain types of building work and the rights of their adjoining neighbours. The Act works to protect the owner undertaking the works, through the party wall surveyors, by ensuring that the work is lawful, whilst also protecting their neighbours' rights in the event of damage occurring.
You may find that the work falls within the scope of this Act. If it does, you must serve statutory notices on all those defined by the Act as adjoining owners. This is quite separate from any need for planning permission and/or building regulation approval.
The process is not as complicated as it may seem at first and can have substantial practical benefits for both parties. Whether it is a Party Wall Notice, a Party Wall Agreement or a Party Wall Award, they will keep your project legal and moving forward with the minimum of fuss.