You guys are from the UK. Be honest: when you're making sinks, one faucet or two?

I haven't actually made any faucets, but I have to say, if I did, it would definitely be two. It just makes more sense. One for cold, one for hot. You can fill something up with cold water, or hot water. You can use both.

I recently replaced my bathroom at home. I replaced it with a single. My kids can't quite understand how it works, so they just turn it straight on everywhere.

It's about just having hot and cold separate. Everything's where it is.