We added a window to the back wall of our garage and decided to handle it as an amendment, now Building Control have requested a new SER certificate and associated drawings.

 

The structural engineer who have already given us the signed Form Q now wants £500 + VAT. I feel like I am being robbed. 

I don't think I have a choice, any thoughts?

I can see it from the SE’s point of view but feel BC is being OTT unless this is a big window with potentially high dead and dynamic/wind loads

It's 1530mm x 1100mm so not significant. Apparently the SE can't just do an amendment or letter stating it's covered. They have to do a whole new cert.