My understanding is that its very common. Usually the owner of the house has 30 days to get out of the house, but they have to pay you 'rent' for every day they stay past closing. Maybe the seller isn't closing on their new house until the day before your closing so they do actually need that time to get everything out since they just gained access to the new house. When we bought our house, the sellers stayed in the house for a day after closing because of that reason. A lot of people try to have their buying and selling closings on the same day, they would definitely need time after close to get their stuff out.