’But I don’t have a boundary wall’ you say …’only a fence and a hedge or, ‘I live in a flat and don’t share a wall with anyone’.
The full and glorious title of the Party Wall Act also refers to fences. The Act also embraces shared floors and ceilings. It also refers to adjacent structures within three metres. Even to your new foundations intersecting a 45 degree line from adjacent foundations in another property. So having planning permission and building regulations approval is not all to think about before starting a build. Don’t press on regardless, let architects advise you.