I've always gauged it by cost of living expenses for working class people.
It's one reason why I love the road to wiggan pier so much. George Orwell breaks down the cost of living in many areas of Britain for the average person. I think when I calculated it out, even me living in the US at $12/hr with a 700 rent payment and all other expenses, I was still living a comfier life than those people. And they put in some LONG days too.
The most interesting thing he pointed out too was it wasnt the corporate places that had the worst landlords and rooms, it was the small or individual owners. Simply because they couldn't afford to fix anything or give you back your deposit.