Edit: Turns out, sash windows are more commonly found in the UK (compared to other European countries), but still not as common as in the US. So, UK = not as hot (so far), thus still probably not worth it (yet) as a market.
Edit: Turns out, sash windows are more commonly found in the UK (compared to other European countries), but still not as common as in the US. So, UK = not as hot (so far), thus still probably not worth it (yet) as a market.
But you should still be able to get two tubes fitted into any kind of window with the right seals. If you were really up for renovations you could get closeable exhaust holes punched through your brick or something maybe.
And yes, there are options for tubes/ducts for the more common window types. Like tilt-and-turn windows, horizontally sliding or all the other kinds of inward or outward opening windows - but most of them are the ducted portable units the original comment was speaking of, which aren't great. There are also some better portable split units, but those are pricier and the install is not as easy. (They're great though.)
I also sometimes miss being able to stick my head out the window but that's a tradeoff about screens and in the end of the day I prefer not to have to worry about bugs.