The doors look like they are flush hollow cores. The doors themselves aren't more than about 30 dollars and if you have the skill to replace them that would be my answer. Second choice since they are painted doors would be to glue and nail a piece on the bottom, then sand, spackle and paint.

Another alternative, if you didn't want to replace the doors, would be to go to a hardware store and get a door sweep to attach to the bottom of each door.

You can attach a wood strip to the bottom of the door, then hide the joint by filling with Minwax high performance wood filler, sand smooth and flat and paint.

We just built a new home and all of the interior doors are 1.5 inch short. I can't afford to replace them all. What should i do? Builder would not replace them or fix the issue