Thanks for that.
Had a look at the Part F that you attached. It seems as though both the English and Irish regs allow trickle vents to be used <5m3/m2/h, by increasing the equivilent area. Scotland doesn't allow this for some bizzare reason - they think it will cause condensation and IAQ problems...where is the research that shows this though.
At the moment if you target 5 and acheive 2 after testing, they will probably ask you to fit MEV, its costly madness. Sorry couldn't attach link to the regs as I've not made enough posts yet!
I'm not anti-MVHR, it's just not always the right answer, I think.