I had an extension built 'before covid' now just finishing BC checks and have been asked for 'structural calculations' My architect is now unobtainable (maybe dead?)
This is from his drawing..
Span in two sections not exceeding 5.6 metre 2 no. x 254 x 254 x 37 UB's bolted together with 10mm diameter bolts at 500cc seated upon 300 x 200 x 150 high concrete pad stones
That reads like a quote from standard design tables.
Happy to pay a professional to state 'this is well engineered' but maybe if I can quote from source I could push back to BC and tell them that design is standard.
My as built span is 2.6 metres, the steels are supporting 2.5 m of external wall plus existing and extension roof loads.