Andi - thanks for commenting. This is a house out in the country, very rural, no inspection authorities. These doors enclose an outdoor/indoor breezeway & are open most of the time.

DId you Google "garage door weather stripping?"

Yes, I did. Pretty generic info though and I found very little on the kind of threshold component I think we'll need. Most geared totally to typical garage installations. This is a new build and the space was never a garage - the whole house overlooks a pond in the country and is up on concrete piers to allow water coming down the slope to run under it. There will be cedar decks built adjoining both sides of the breezeway, so the thresholds will overlap wood outside and the poured concrete floor inside.

Just because you have no inspection does not mean you should build a house poorly. If this is abreezway then who cares it is not meant for living space who cares but if living space then no matter whether there is inspection or not you need to use your brain and build this the right way. IMo without pictures we are guessing .

Patricia, thank you for commenting. My husband and I both have architecture design degrees and are working with a fully licensed general contractor. No corners are being cut in any way. Just want to be able to close the breezeway in inclement weather and keep it water tight. We have very strong storms in our part of the country so keeping water out is a priority.

Have you tried searching for a boat house door? Not sure if my idea has any merit, but sometimes looking in a direction leads you someplace helpful.

Thank you! Great idea, Diane!