Ah, sorry, I meant can the remaining loft above your loft conversion still access the outside world without going via the eaves storage space?
But perhaps it's immediately the ~25mm cavity below your roof felt which joins the eaves storage space? Essentially you need to allow the outside world to get to the cavity beneath your roof felt in some form, so making the eaves storage space more airtight might not be the best approach unless the roof is already separately vented to the cavity underneath and doesn't rely on the eaves at all.
Thanks everyone! On the basis that a small hole in the wall doesn't look like a deliberate ventilation tactic, I'm inclined to plug it in, then fit a draught excluder to the bottom of the eaves door into the loft room, and leave it at that.
Ah, sorry, I meant can the remaining loft above your loft conversion still access the outside world without going via the eaves storage space?
But perhaps it's immediately the ~25mm cavity below your roof felt which joins the eaves storage space? Essentially you need to allow the outside world to get to the cavity beneath your roof felt in some form, so making the eaves storage space more airtight might not be the best approach unless the roof is already separately vented to the cavity underneath and doesn't rely on the eaves at all.