party wall letters

[findyourbacon]

I am planning a kitchen extension and a loft conversion, and need to produce party wall notices for my neighbours. Does anyone know which ones I will need for each side - there are 3 versions and I can't work out which ones I need - the versions are: Party Structure Notice, Notice of Adjacent Excavation, Line of Junction Notice.

I'm finding the information on the various websites a bit overwhelming, and could do with some plain English versions - help!