Wooden door - draft seal at bottom

[Spreadsheetman]

We are replacing the wooden external-spec door into our closed porch (unheated) and wondered if anyone has any suggestions for threshold seals at the bottom?
 

The existing threshold has a simple upright bar running across the width in the centre of the closed position and the door has a matching lip at the bottom. There was once a compressible seal between bar and lip, but this fell apart long ago. Naturally a draft comes in.

 

I’m going to a bit of trouble to reduce heat loss into the porch (e.g. replacing single-glazed sidelights with double glazed units, new door with double glazed panels) and the bottom of the door is the definite weak point of the plan.

 

 

Edited March 1, 2023 by Spreadsheetman