The window is indoors, looking into an internal games room, just like to have a feature but be able to watch littlies as well when busy in kitchen. It is installed with a jarrah timber frame. Many thanks. Allie

Thank you everyone. I hadn't thought of the separate drape for the transom, I think I'll allow some fabric for that. I feel confident that my idea's not too way out now. The most important thing is usability & comfort I think. I do love shutters too - my Mum has them & they've really lifted her place but in this case we want maximum visibility onto our verandah. Thanks again :)

the height of it is only roughly 10cm at the peak, and its boxed in on the inside, so really just looking for something to close off the area on the external wall. Anyone heard about mouldings and what those involve?

usually nothing better than fresh air but i wonder why there was a fixed window installed in the first place? is there a busy street or very close neighbours? and your climate suits different styles and different styles of window provide better ventilation.. and expensive is a relative term and much more depends on labour involved and unexpected damage to surrounds than the actual cost of the window....sometimes a new double glazed pane can be installed into an existing window frame but depends on what you already have ....we've replaced all the windows in our house with double glazing and would expect to pay around $1000 to replace a modest sized window (without any surprises) but take close up photos of the inside and outside of the windows and contact your local window manufacturer for advice about suitable windows and they may be able to recommend an experienced window installer to do the work