SOLANO’S supplies door slabs and pre-hung door assemblies. We provide a wide selection of doors from several manufacturers. Click on the logos below to review styles and options. Door sizes are also specified by width first, then height. The most common door height is 6 foot 8 inches. Therefore, a common exterior entry door would be specified as a 3068. The opening in a wall for a pre-hung 3068 door should be two inches larger than the door. In our example that is 38 inches by 82 inches.