One of the houses I've been involved in (but not responsible for, thank goodness) is not quite a McMansion, at least not in plan. I went out to see it under construction today, and learned something important.
A twelve-foot ceiling is too damn big for a single-family house.
This house has ten-foot ceilings throughout the first floor, and twelve in the 'Great Room'. The first floor has an smaller, alternate living room, which I approve of as what Sarah Susanka calls an 'away space.' It can be used as a guest room, a pool table room, an office, a first floor master bedroom - and it has a ten foot ceiling, which feels positively luxurious. But the twelve footer just outside it feels like the gym at the YMCA. I would not want to weather our standard thunderstorm in that room.
Ironically, the best room on the first floor, is a small screened porch, maybe 8x10, tucked into one corner, and elevated amongst loblolly pine trees. A thunderstorm would be great in there! Curl up with a cup of hot tea and a nice book, with a dog on my feet... much better than the echoing 'great room'.
And I don't think I'd like to host a party in the giant space, either. It'll be echoey and confusing in the chatter. I'm not a tiny person - I stand 5'-7", which most people think is tall for a woman, and my style is pretty bold and gypsyish. I used to be a dancer, and I move like it, and make whole body gestures that take up a lot of space. Even so, I just feel like I couldn't master the room, you know? It would master me - and that just feels wrong for a house. Okay for a hotel ballroom.
I've got friends who regularly hold 50+ person parties in their house, and raise 8 children there. Next time I go over, I'm taking my tape measure - I'm sure that ceiling isn't more than 9 feet.
And I don't even like ten feet in the kitchen. Too much. No coziness. Just wasteful.