If I remember correctly it was stylish back then for rich folks to have a house in the city plus a country home too.
I grew up on a farm. The people who had land next to ours were from the city. Dad called the fellow a gentleman farmer. I remember them as decent folks. When they brought their friends from the city they almost always stopped by to chat with dad.

I didn't catch that, but yes, that makes sense.
Poorly Lived and Poorly Died, Poorly Buried and No One Cried

In one of his televised reports, the smarmy newsman referred to the house as the Archers' "home away from home." So they probably had a primary residence in a tonier neighborhood, while this house was just somewhere to get away from it all. Indeed, it makes sense for someone recuperating from a stint at a sanatorium to retreat to their country home.

Deputy Charlie made Barney Fife look like Stephen Hawking.

She had a beautiful house though. Very swanky and impressive. And was she a doll! She was a bit of a b***h and a lush, but with those other assets who cares?

Must be pretty damned safe if Nancy has no problem with wearing a priceless diamond while out on a casual drive.

It supposed to be the California high desert. Just before we see the "satellite" for the first time, the newscaster for KRKR-TV says the object "will be over our California desert any minute now." Then again, this is a man who confuses South Africa with New Zealand on a globe, so perhaps his word is not too reliable.
More definitive: When Nancy is driving toward her ill-fated rendezvous, she's on the California portion of US Route 66 (there's a road sign), so we are supposed to be somewhere in the Mojave.
Why is she there? Perhaps it was her family's original home town; they could have been mining millionaires or something. I agree that the house seems a bit modern and urban for a country getaway.

I always wondered where they were supposed to be living. The house they had looked straight out of the Los Felix section in LA. but the surrounding area looked very Arizona to me.
" I don't agree, but I do understand" - Chris Rock

Safer than living in a city with all the attendant crime and corruption.

They wouldn't be the first rich people to live in a one horse town.
It's easier to be a big fish in a little bowl. But I think maybe Nancy just liked the rural lifestyle, lol.
It could have been a tiny town forty miles outside of Phoenix or some other major city out west.
Technically speaking, it was no doubt cheaper to film in the middle of nowhere. I love the location, rich people in a bumpkin town. That kind of irony is found only in a classic b movie.
" Cristal, Beluga, Wolfgang Puck It's a f#@k house."