I don't think there's any cut-and-dry answer for every couple. Some people were raised with the idea that married couples retain their own space and that that space comes in the form of their own bedrooms, while others can't conceive of sleeping apart. For myself and my husband, we can't sleep if we don't have the other to snuggle up to at night, but for my husband's grandparents (who raised him until their death) separate rooms were just normal, and they maintained their own bedrooms for nearly 80 years of marriage. That said, I know I do have to have a space that's just mine, and so does my husband...we just choose it to be areas of the house (and eventually particular outbuildings) that are there for alone time and personal space, other couples might make that personal space be a bedroom for each. Whatever works best for the individuals involved :).