More can always be said, and I'd be happy to go into any follow ups, but you might want to check out this thread of comments I wrote a few months back.

In addition, I should note that this is mostly about housing in large towns and cities. But many/most Soviet residents also had dachas, or country houses. These were usually fairly small (they were mostly just a cabin or a cottage with a small plot of land for gardening) that were used on weekends, and often they were privately owned, the technicality being that the land was public and the building itself was leased or privately constructed. I'm positive I wrote a longer answer on that, but google and Reddit search are both failing me in finding it.