Higher quality pre hung doors are usually manufactured with 1 5 clearance under the door as described above assuming the flooring will be premium as well in the 3 4 range.
Gap under bedroom door.
There is an approximately 1 5 gap at the bottom of the doors.
My contractor just hung our fancy dancy un painted solid wood door slabs in my 100 year old house with solid hardwood floors throughout.
I think it is too big and think a 1 4 1 2 gap would accommodate any unevenness in our floors and allow us to use area rugs.
It s often not wisdom at all and you may get different versions of it depending on which convention you believe.
How to fix a gap under a door.
Seal the gap under the door.
The conventional wisdom on door undercuts.
But for finished conditions bedroom closets area with w to w carpeting ect 1 2 max.
Door gaps especially on exterior doors can be serious energy wasters.
Cheaper pre hung doors give about 1 1 25 clearance and this is because the rise of thinner floor systems for the mass consumer market.
Door undercuts typically won t allow enough air to get out of the bedroom unless you leave a gap bigger than most people want under their doors.