My Mrs asked me to look up something on Victorian housing in London for a lecture she's preparing. I came across this Wiki page which is an easy read about the boom in house building in the Victorian years resulting from increased wealth, the industrial revolution a general movement from rural areas into the bigger cities. If you think you might be interested, I recommend it:

https://en.wikipedia.org/wiki/Victorian_house

But I was prompted to post this having seen this fascinating item on another website which refers to how the term 'slumming it' came to be. Bear in mind that the great middle class only began to develop in Victorian times; initially you were wealthy or poor.

...a surprising aspect of society in the late 1800’s is that the wealthy upper class had their own curiosities about how the poor lower class lived. They would actually put on their “common clothes” and go down to the slums for sight seeing trips. “Slumming” became the name for this form of tourism. Many of the upper class men and women alike would disguise themselves in lower class clothing and head to the slums for a night or two to indulge in the guilty pleasures that could be found in the streets and boarding houses of the slums.

For further really interesting reading on how the poor in Victorian times lived, try this one:

http://victorianchildren.org/victori...torians-lived/