thank you everyone. that’s really helpful, there’s mixed opinions on trickle vents, some saying if it’s a new window then you need to add trickle vents to meet regs, others say, if the window doesn’t have T.Vs then you don’t need to put them in if windows are replaced. it’s well ventilated victorian house if you know what i mean 😂 gappy floors/ doors. i will change that over time but its by no means not going to be well ventilated… and we windows are opened.
its tricky regarding sash, the house it traditional so don't really want to go down the route of “modern” windows, but also dont want to pay a fortune for something that isn’t effective at noise reduction. hence faux sash casement …