I think it would depend on the levels of intimacy. Say, if the two wives were acquaintances, you wouldn't want to spend every waking hour in a house you felt was never truly yours. So I see a compromise:
If you are to have two wives, you should make a considerable sum of money. Mainly because of the risk associated with having two partners, it's best to pad your lifestyle with plenty of savings and a large house. If you have a large enough house, split the house into wings and spend nights in separate bedrooms with either partner.
But of course, it's not that simple. Women, like men, are quite territorial. So, the default position here is two separate houses, with a compromise of a shared house with the stipulation of it being a very large house.
The next level of intimacy would be the two being friends, and I think that would increase the likelihood that the shared house idea, with separate wings, is a good idea.
The next level of intimacy seems to be friends with benefits, in this case, a house, with separate rooms seems reasonable.
The next level of intimacy is an intimate relationship, if this is the case a shared house seems likely and reasonable. Not just a shared house, but possibly a shared bed.
The next level of intimacy is a common law marriage between the women and the man, where it's likely that you'll share a house and a bed.
Thoughts?