In the UK the local council (town hall) only holds the plans relevant to making planning decisions, not the detailed construction plans. Private companies can sign off the building safety (known as building control) usually as part of providing a new build warranty on the development (but then one of the biggest providers, Zurich, offloaded their portfolio to a shell company than then went bankrupt under the liabilities due to incorrectly signing off buildings. The whole situation is a major scandal in the UK at that moment)