From the last step we continue on the frame of our Straw Bale wall. Before we place the batten on the frame we measure the distance of our window and label the point by pen on the batten then placing the other timber on the frame so that the measurement don't get error as possible as we can, after that we place right angle plate between two batten to hold them together by bolts so they are tight and stable. Picture below is the frame that we finally get by the method previously. Using the same method another side of the wall frame is done, after the window frame is placed we connect the two column with timber that we cut out previously with the width of 300mm as our window size are 300x300mm.