Rows of McMansion-style houses have been built with very little offset by abusing rules intended for townhouses. In the cases I've seen, a single shared wall -- often just a token wall made of brick connecting two structures on the outside -- allows the McMansions to qualify as a multiple-family dwellings and obtain higher density, dramatically increasing profit.
.
.
.
... yes, I'm agreeing with you. And cringing as I remember a visit to a friend who'd taken up wine cellaring some years back, describing various vintages as "product". You'll hear that in media, app design, clothing, food, restuarants. Pretty much everything. MBA-speak gone mad.
A "dwelling" mostly comes up in the contexts of censuses and elections. One census form needs to be filed per "dwelling", and should include information about everyone who has dwelled there for the majority of the last year. This includes, for example, people just crashing on the couch, even if they're just on vacation and "live" somewhere else. For another example, this includes homeless shelters: the people staying in them can say the shelter is their "dwelling", though they're unlikely to feel like it's their home. (Also, a "dwelling" is not necessarily residentially zoned. You might be dwelling in a storage unit. It's not necessarily legal, but the government still needs a word to describe "places people live" that includes such cases.)
There's also "residence", which is just "dwelling" in fancier clothes, though usually implies residential zoning.
As in 'to dwell on' something. My dictionary says it comes from a norse word meaning 'to go astray'.
To my ears it's like 'hovel' and implies something like a hole in the ground - dark and dirty where an animal might live.
"To dwell on" something isn't inherently negative either, it simply means to spend a fair amount of time thinking or focusing on a single thing. Whether that's good or bad depends on the context, and is not implied by the word itself.