Front door threshold raise?
 

There is a 1/2" gap between the bottom of the door and the threshold, was thinking about putting 1/2" block of maple or something under the threshold to raise it up.

A pic would help...I'm always wary of messing around with door thresholds without seeing all the issues.

Exterior door?

Some thresholds are height adjustable.
Look for two large screw heads that raise/lower/level the thresholds when turned.

Is the rubber seal missing in the threshold?
With a picture we can figure it out.

Hi folks,
Perhaps a door shoe or sweep is missing on the bottom of the door.
That would take up about 1/2".
All good questions an comments here...Where is Garlandkr?!

RC/DG