Most of my historical novels have been set during what is known as the Victorian era. According to Wikipedia, this was "the period of Queen Victoria's reign from 20 June 1837 until her death on 22 January 1901. The Victorian Era style of clothing and style, however, ended in 1912." And although it's named for Britain's queen, the era was experienced in America too.
I have lots of research books on Victorian etiquette, clothing, carriages, inventions, homes, etc. It's the (American) Victorian homes I've been looking at a lot lately.
I always either find a house plan or sketch one of my own for the places my characters live. As an aside: The hardest sketch I ever did was for the medieval romance that I wrote way back when. I didn't need just the castle. I had to draw the keep and know where the drawbridge was and how the village was laid out.
Recently, I purchased a book with a CD of Victorian homes. (Oh, be still my happy heart!) So I thought I'd share with you a few of my favorites.
Let's not forget the middle class city dwellers. Usually long and narrow, these apartments had lots of stairs to climb, day in and day out. No one needed a pedometer to make sure they took enough steps.
If money were no object, I would buy a big, old Victorian home and restore it to look as it did 120 years ago while having all the modern conveniences artfully disguised. (I may love the past, but I'm awfully fond of my creature comforts.)