You can still put windows in airtight homes. They're usually triple paned to insulate well, but nothing is stopping a builder from putting windows in. Most pass

You can still put windows in airtight homes. They're usually triple paned to insulate well, but nothing is stopping a builder from putting windows in. Most passivhauses do this. ERVs are additional engineering needed for when all the windows in the house are closed, but yes are necessary in those situations. ERVs aren't really that much more expensive than an exhaust that needs to be added in most homes anyway to release ventilation/dryer exhaust/cooking fumes. Only the really, really old homes don't have something like this and many of them have chimneys.