Anonymous wrote:It could easily be added on/remodeled.
Cool, but it costs money on top of already hefty price of a build. Why would you build a custom home without this? Why would you need a library more than a formal dining room? I get the usability of ground floor main bedroom suites, but I don't get why you would have a library and not a dining room in an 8K sq.ft. house. Much smaller homes have formal dining rooms. And they are useful if you have guests over even for a casual gathering, because your main "breakfast table" doesn't need to be cleared and you don't even need to tidy up your kitchen, as you won't see your counters and casual family table from your dining room.
It's great to not have to prepare for guests, but always have a nice tidy dining place without daily clutter. I think maybe this is a reason formal spaces like sitting rooms and dining rooms are making a come back. If you are loaded to afford huge new builds and you are busy, you can separate family utility places from formal guest places. Even having a friend over for a takeout is easier in a formal dining room.