No, they didn't. I remember we had a discussion on the subject, but I can't remember the pros and cons that led to the decision to give them a miss. I think the upshot was that frankly, they don't make a whole lot of difference. There are other air vents elsewhere in the house.

I'd also recommend that you get your roof looked at, if its not been replaced since it was built. That's also made a huge difference to the house being wind and water-tight.