@Barleysugar85
We had a lodger up until last year. I wouldn't again personally. It's really hard to relax in your own space, you constantly feel like you have to apologise for any mess anywhere in the communal spaces, it gets awkward when you both want a bath or a meal at the same time, it's like having a visitor that never leaves. And there is always some little niggles that would drive you crazy (not rinsing out the bath after use/ never takes a turn cleaning the loo, whatever it may be!). The day we decided to just be poorer and make do without the income was like a big sigh of relief.
We used to rent two rooms to mature students and I loved having them around. I love the idea of a visitor who never leaves! And I'm very laid back, it's very rare I get annoyed with people, life's too short IMO. My eldest was 4 when we moved and stopped being able to do this, and everyone who lived with us was great with him, he got a lot out of it
We had lots of different lodgers over the years as they came and went with their courses. The only one we had an issue with was the time we let ourselves be convinced to rent to someone who wasn't a mature student. He was a dick and I had to ask him to leave. We only did rolling month contracts - lodgers have very few rights - so we didn't have to live with him long.
These days, I'd only rent to women. Renting to mature students works really well, I've found, as they're there for a purpose, and I like that they come for a while (usually around 10 months) and go when their course ends. It means if there's anyone who doesn't fit into the household well, we don't have to live together for too long!
The key, also, is to be really clear about how what the house is like and the kind of person you're looking for. We can be a bit messy and noisy and we need someone who's fine with that.
We share our whole house with the lodgers (minus the bedrooms of course!) - they're not expected to hide away in their rooms, and we prefer people who are social and want to come hang out with us sometimes. We always invited our lodgers to eat with us, (and mostly they chose to, up to them) so there was rarely an issue with wanting the kitchen at the same time.
We met some really interesting and lovely people this way and a couple of them have become some of my best friends, we're still in each other's lives a decade or more after they moved out.
Renting to lodgers isn't for everyone, if you don't like visitors to stay for long, as you say a permanent visitor would be many people's idea of hell. But it works for us.