We are opening up our kitchen (taking away the external doors and part of a wall ) which will be getting replaces by a steel beam to support where the doors used to be to our extension ( currently at the planning permission part ) are engineering certificates a must for the use of the steel beam? would it be required if we were keeping the external doors as they are ? asking as we have been quoted a price of almost a thousand pound for the engineering certificate (which would include having a look at the current foundations and digging a test hole ) seems very expensive , any help will be greatly appreciated ,thanks