Hi Jimmy, please cut me a slice of humble pie. I gave a reflex response, not a considered one.
We do not know the type of screen proposed. I had assumed a privacy or solar screen made of metal with either frosted glass, slats or louvres. It could possibly even be an insect screen. Nor do we know the proposed scope of works, whether the screen is part of a refurbishment of the balcony area.
Even if the erection of the screen can be characterised as a renovation, situated on the corner of the balcony it is likely to alter the external appearance of the lot. It may be out of the line of sight of other owners, but it will at least be visible by the owner. The proposed installation of the screen would probably fall outside s110 SSMA as the section does not require the change to the external appearance to be visible from any given viewing position.
I do look forward to reading the chronicling of the adventures (or trials and tribulations?) of Strataboy.