Tweet This weekend I was in Milwaukee with my husband to visit his family.  My brother-in-law had us over for tea and I helped him put up his Christmas tree.  He lives in a one-bedroom apartment on the 3rd floor of an old mansion. That mansion, that was once built for a single wealthy family, was later converted into 4 apartments.  My sister-in-law, who also lives in Milwaukee, recently bought a duplex that was also once an old mansion but was turned into a duplex later.  Milwaukee is full of such buildings in its neighborhoods – single-family mansions turned into…