A fully qualified structural engineer will plan and oversee the whole of your project at each stage. No building job can be done competently without the expertise of a qualified structural engineer.
Any alteration or extension to your home will make significant changes to the structure and integrity of your home and the correct supports and new steels must be used to ensure its structural integrity is maintained.
A structural calculation is done and a copy sent to the building inspector who will conduct his own due diligence on the calculations provided and carry out site visits to check and qualify the works done.