I understand. When I met my DH, it was with the understanding that he would one day buy his widowed mother's house; it was always his plan. I had no objection, since it is in a good neighbourhood and has a lovely view, but I never really loved the house style.
Over the years (we've lived here now for over 40 years), I have indeed made it my own and it is comfortable, but has no architectural style at all, it's still the same 60's box no matter what.
One of by book group ladies had a house on the same street, a 30's craftsman bungalow. I love that house! Square entry hall with symmetrical rooms on either side, lovely wooden staircase, small kitchen at the back, tiny but charming fireplace in the living room. It's creaky and older, but so homey feeling.
So yes, I get house envy! I dare say there is a difference between envy and jealousy. I see envy as more wistful and jealousy more negative.
We also have friends and relatives with much more posh homes than ours, but no, I don't envy them theirs. They worked hard for them, but they are not my style, so even if I had the money, I would choose a quirky little craftsman over three car garage and pool.