You will definitely want to install tile or some other sort of weather and stain resistant flooring by your sliding glass door. Not only will carpet likely get very dirty there, it will also be subjected to water and other weather complications that would be better handled by a more non-porous type of flooring.

Thanks so much! Now just to figure out what will look best there. :)

Personally, I hate patches of tile in front of a door within a larger room
- unless you're going to set off that space architecturally with a partial wall, columns, etc, it always looks out of place. IMO, It's better to have the entire room floored in tile, then use a large area rug/carpet over it.

Thanks, bepsf. I think we might actually go with hardwood in the space instead of mixing the tile and carpet.