I have on the drawings a continous 25mm gap vent to provide at my soffits for ventilation to my loft conversion.
Now I looked at putting one of those circular vents between each rafter(450mm c/c) but thats not nearly enough area. If I look around at roofs in the area no one has as many roof vents as that! even though its not enough so is this area not as enforced as others with building control.
I realise breather membrane reduces it but still the ventilation on houses with loft conversions do not seem to have anything near whats asked or have I picked this up wrong.