I remember being pleasantly surprised by the discovery of tiny electric water heaters in the UK. We have them here in the US, I have since found out, but we also tend to only use them in fancy expensive houses or remodels, which is stupid.
Also, maybe this was more of a Glasgow-flat specific thing, or maybe this was a "student-housing" thing, but in Scotland I remember being much less pleasantly surprised by the fact that the showers were basically just walled off with a half-wall functioning as a splash shield, without curtains or a glass door or anything. How do you keep the heat in, you crazy fucks? My butt was so fucking cold every time I showered! I realize baths are way more popular than they are here, but still. Hands down the worst part of every visit, including the one where I had bronchitis/walking pneumonia.