Works
Side-return extensions
Infilling the side alley can mean a new wall at the boundary and new foundations near the neighbour’s flank, sometimes as well as work to the existing party wall.
This is general information for England and Wales. It is not a decision on your building. Status: pending project-specific review by a qualified Party Wall professional. House-style review 27 September 2026.
Do not rely on the alley width
An alley that feels wide can still put a trench inside the distances the Act cares about. Measure on the drawing. If the neighbour’s kitchen window is hard against the boundary, say so. Access for building the wall may become part of the later discussion. It is not decided here.
A Party Wall Notice does not replace planning permission, building regulations approval, leaseholder or freeholder consent, or structural advice. This platform does not provide legal advice and does not issue Awards.