Yet another question on these fine forums. Nearly every room in this bungalow has a 6" hole drilled through both the inner and outer walls. A direct hole from inside to outside with a cover on the inner and outer. The is just above skirting board level. Floors are concrete. The cavity wall insulation was removed some time ago. Are these big holes needed? What would you do? Block them up both sides? Just block up the inner?
Brick them up inside, outside I would just leave grille in place outside, will allow cavity to vent, as I have done here.
No as only one 'new' gas fire in living room of which is being taken out. It has never been used. These 'vents' are in 4 rooms.