The work does not become legal because it is finished. Unpermitted building work remains a defect that can be enforced against, must be declared at sale,...
Approval is normally required for anything that changes structure, drainage, electrical circuits, gas installations, thermal performance or the use of a building. Cosmetic work, like painting,...
Four documents matter at sale if the property has been renovated: the planning decision or lawful development certificate, the building regulations completion certificate, the electrical certificate...