Passive air vents question

[FluffyJellyCat]

Should a passive air vent have some kind of one way system or filter? Just had a trade out and think it should be open like this? It’s also been left full of brick dust

I think there should be an air brick on the outside. And insect mesh inside.

Yes I think so too. The hole is big enough for a bird to get in the make a nest. There is a draught.

We contacted the builder who we got via check a trade but no reply. Think we will have to leave a bad review to get check a trade to step in