Going to go slightly off topic so apologies. But to answer your question, I think Americans would think a normal European house would be a signifier of poverty judging from what they'd see on screen. That's probably why for films and series with more international audiences, very grand, historic houses are often used to signify wealth.
You have to take into account that American shows are much more a sales pitch than European ones.
There's a lot more cuture around promoting consumer capitalism and what's aspirational, placement for products, agendas, trends etc. SATC being a classic example. There's a tendency to show the best of the best, not 'somewhat shit places' like in some British shows - which I love and prefer.
American tv/film culture is highly aspirational and 'Disney'. There's much less criticism of shows along the lines of 'that did not seem very realistic'. For example, note how the US is a majority overweight/obese country, whereas from their art you really couldn't tell as cast and extras tend to look conventionally attractive and thin.
If you've ever been to NY, Chicago, LA, Vegas etc, they are often shown as beautiful, safe, tidy, aspirational environments, whereas real life can be shocking and really differ.
If you want to see what poverty in the US looks like, watch Shameless US version, it's quite good. Poverty in the States can be quite shocking.
As PPs have said though, land is cheaper and building houses as well, so space-wise expectations are bigger than in Britain. Think of Mitch & Cam's house in Modern Family, which is supposed to be a bit of a 'poor house' in an affluent part of LA - in Britain this would be an amazing house.