" The bathroom was off the kitchen." from The End of The Story by Lydia Davis, p.48
As far as I know it means that they are separate, am I right? Does it mean that they are in two different sides of the house, not adjoining each other?
Yes and no. It does mean that they are separate rooms but you have to go through the kitchen to get to the bathroom, so very close together. Thousands of terraced houses were built to this floor plan in the past, though I think modern designers would avoid it these days.