Means you are responsible, doesn't mean you have to do it all.
I don't do the electrics, or the roofing, I sign it off though.
Something goes wrong, my problem.
Guess what! - I make sure we use the right people, suitably trained and qualified for every part. If they're not, they're not allowed on the job, from design to mounting an Isolator, no argument.
If you aren't appropriately qualified, you can't do the structural assesment, you can sign it off though for MCS purposes, so lang as you have seen that it has been done by a suitably qualified person. If you haven't seen it, don't sign it off.
Your butt is on the line.
Sounds like a change in job spec, increased reponsibilities, with an employees hat on (haven't worn one of those for a looooong time) seems like an argument for a pay rise!
It's about making sure the job is done properly.
Oh, and you'll need to know the MCS documents inside out, because come audit time, guess who has to be there!