It is becoming less and less common to build window frames for an entire house from solid wood. I had planned to make a video with the door frame, but it turned out to be longer than expected, so I divided it into two videos. I always have difficulty fitting the sliding glass door frame alone because it is so large. If only I were 5 cm (1.97”) taller, I could easily install it. The frame was only one and a half ken (2.72 m / 8’ 11”), so there was no problem, but if it was two ken (3.64 m / 11’ 11”), it will sink in the middle and be even more difficult to install.