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I would also ensure whoever is doing the building works has the necessary contacts to support you. I’m having an extension built and my builder has liaised with building inspector, structural engineer, water board etc. This was included in the price. They do this every day so if they are decent will have the required connections.
I would go back to your architect and adjust the plans, I did this 3 times, and after planning was approved my builder liaised with the planning department and building inspector on any small changes.