Do you need planning permission for a knock-through?
Planning vs building regs — the distinction that confuses everyone
Planning permission is about what the building looks like and how it's used. Building Regulations are about whether the work is safe and properly built. A knock-through changes neither the outside nor the use, so planning isn't engaged — but the moment the wall is load-bearing, building regs are. The two systems are separate: getting one is never a substitute for the other.
The exceptions: listed buildings (internal works need listed building consent — criminal liability if skipped), flats and maisonettes (lease usually requires freeholder consent, and structural walls may belong to the block), and openings in external walls, where a new large glazed opening can engage planning in some settings, including conservation areas.
Related questions
Is planning permission needed to open the back of the house for bifold doors?
Usually not for a like-for-like or modestly enlarged opening under permitted development, but conservation areas, listed buildings and flats change the answer — check with the council or ask us at survey.
Who is responsible for getting the approvals — me or the builder?
Legally the building owner, but a competent contractor arranges building regs as part of the job. We lodge the application, book inspections and hand you the completion certificate.
Ready to take it further? See our knock-throughs & new openings service.