We are intending building a single storey extension as highlighted red in the image below. This will not be on the boundary with our neighbour just slightly off.
The party wall act seems to imply that a party wall notice is only needed if we are within 3m and will be excavating deeper than the bottom of the neighbours foundations.
Does the party wall act apply where building perpendicular to the neighbour?(all the diagrams seem to imply measured between parallel walls / buildings).
I don't know how deep their foundations are yet - is it sensible to have a party wall notice etc anyway?

Thanks
Richard
The party wall act seems to imply that a party wall notice is only needed if we are within 3m and will be excavating deeper than the bottom of the neighbours foundations.
Does the party wall act apply where building perpendicular to the neighbour?(all the diagrams seem to imply measured between parallel walls / buildings).
I don't know how deep their foundations are yet - is it sensible to have a party wall notice etc anyway?

Thanks
Richard