Here's my tuppence worth (as a newly retired wife):
Firstly husband and I have always had lives of our own and a big area that overlaps in the middle, which is good.
From time to time during a long relationship I think it is to be expected that there will be an initial adjustment period when circumstances change. We both had to make massive adjustments when we came to live in the UK in 2000 and gave up our comfortable home in SA for a studio flat in London. From time to time, sparks flew and at one stage I thought I should chuck it in. Time passed and the waters calmed.
14 years on, we have our own space in the house and when each is in that space, the other doesn't intrude other than to offer a cup of tea or coffee or perhaps a "Guess what?" comment. My space is upstairs in our bedroom, on the bed, surrounded by laptop, Kindle, books, cup of tea etc. His is in the lounge with the crossword and the TV on (which is why I retreat to the bedroom, happily I might add).
Since we are both spending a lot more time together during the week, we've been hassling again. Now I know it will pass and we will again settle into a pattern that suits us.
What I've described though is very different from living with someone that you don't really have affection for any longer.