Each door that Kloeber supplies will have a threshold and a cill. The depth of this part of the door can be installed below the floor level so your finished floor inside lines up with the top of the threshold. This will mean you don't have to step over this when walking outside. Sometimes this may mean taking out a course of bricks under your existing aperture, which is quite simple for any builder and as with any technical or building query, Kloeber are always at the end of the phone to advise on any details regarding our doors. There would usually be a small difference between the internal and external floor heights to ensure a fully weather tight seal. Click on the technical tab on any of our products on the website to see threshold details.