As far as I am concerned, corner windows were a perverse invention. They are also difficult to dress. In this case I decided to make an upholstered cornice board and gantt roman shades do the job.
You probably can't understand how many ways making a corner treatment messes with your perception. Before I began work, I measured and drew the outline of the cornice board. I made a template of what the top should be and then went to the client's house and literally held it up against the ceiling to be sure it was right.
Once I knew I had a good outline of the top I could cut out the pieces and glue and screw the pieces together. I didn't want it to be too deep and take space out of the average size room.
The form is shown on the right.
The structure is then covered with furniture batting and the fabric is attached as with any upholstered cornice board.
In this case a gold braid was added to the top to accentuate the metallic gold in the fabric.
The bottom was kept flat with no shaping.
The design of the plaster decorative elements allowed me to trim one down to the scale of the small window and keep the original size for the larger one.
The plaster elements were attached as a part of installation. They had to be positioned over the center of the actual window which means they are not centered on each board.
The stripe of the roman shades help add the needed vertical effect under the very horizontal top treatments.
I hope this was useful. Please let me know what you think.