Path 1 — fix it

Open up the work, correct it, re-inspect, and get a Completion Certificate. The default outcome on most projects.

Path 2 — Regularisation

For unauthorised historic work, apply for Regularisation. The Building Control body will require opening up and testing to assess compliance. If the work meets standards, a Regularisation Certificate is issued.

Path 3 — enforcement

Rare, slow, and serious. In the worst cases the local authority can require alteration or removal. Most disputes settle long before this point.