My house is 2.5 years old,and for some reason my daughters room is so cold that I need to put a small heater in it, just to keep her from getting to cold. There is one register in the floor under the window, and a return air on the wall 6 ft. high on the opposite wall. The closet has the attic access in it. I have looked in it to make sure there are no holes or anything that would be causing the problem. Can anyone help me out here.
My builder has been useless.

It is a good idea to make sure no cold air is getting into the room so be sure the attic access is sealed well. I believe there are kits available or you can make your own to seal and insulate the attic access.

It is a good possibility that you furnace duct supplying that room has a problem.

First make syure the register is open all the way and make sure nothing got put down the floor register. Remove register and feel around (becareful as to not to cut your fingers on the sheetmetal) to see if anything is restricting the air movement.

Next and more difficult. I a damper for the duct is available it more than likely will be located in the basement. Look in the basement at the duct to see if there are any samall handles that look like this. Report back.

My bed room is cold but in my room the air is cool why?

My heating unit is up in my attic.

My bed room is cold but the other room are nice and hot. Why is my room cold. My heating unit is in my attic. Could some one please help me