Despite having spent more than half of my life in UK I still struggle to get used to outward opening windows. In the rest of Europe you open your windows inwards which allows you to clean both sides of the glass. Here you need to hire a window cleaner, or climb on a ladder, to clean any window above ground floor. I know there are historical reasons for windows being the way they are but it’s very impractical. It’s just annoying and inefficient.
