We have enough rooms, but I plan on our DDs sharing a room.
I shared a room with my sibs most of the time growing up. My friends with older daughters say they frequently ASK to share a room, even though their home has enough rooms for them to have their own.
When they are teens, I expect they will want & get their own.
But FYI, I think in my area it's actually illegal to have a bedroom in a basement unless the windows are big enough and accessible enough to escape in case of fire.
Jo
DD#1 "JellyBean" 6/08
DD#2 "Ha" 6/10
"Theory is great, but as I'm in the trenches of diapers and dishes and ear infections, I try to relax and focus on what's most important: love."--mjs64