To Australian Home Designer. Thank you for your advice but I'm not trying to replace the doors with a window. The double glass doors are on the study, and they open onto the very small balcony which measures approx 2M X 0.9M. The balcony has slate type tiles on the floor, there is a roof above and it is enclosed either side by concrete? walls. The balcony has an opening about 2 M wide by 1.5 high, which is what I'm trying to addres. The balcony is next to useless as it is and I could make more use of it if I could enclose it. I tried to add another photo to give a better idea, but for some reason I wasn't able to. So, I'm not trying to replace a window but install something in an open space to act like a window. As this area is considered common property (even though no one else can have access to it unless they walk through the apartment), I have to advise the corporate body. Chances are they'll ask for me to arrange for a by-law to be drawn up. It never ends does it? The other thing I should mention is that Council said (when I first approached them) that the developer would have used every available space to the enth degree. The developer has confirmed this with me. The block is almost 2 years old and all owners are the first occupants. Thank you for taking the time to respond. It is much appreciated.

http://www.ecostardoubleglazing.com.au/upvc-double-glazed-windows/

Something to consider with roller blinds- The blockout ones can really block the airflow in Summer, and if you do leave the louvres open, the slightest breeze will cause the bottom rod to bang against the window frame. You can fix them so they don't do this, but again you have the reduced airflow.....which is why you have louvres in the first place. We have the same problem. My son's bedroom. He seems to have adjusted to no window coverings. Luckily we have no privacy issues.

Thanks for this suggestion. I need to be as snug as possible in the cold winter months here in Beechworth, ( the rest of the year is glorious), and I'm looking for the most effective insulation for the windows. I believed cellular blockouts would achieve this, but then thought Double glazing + blockout might be "over the top". I can't see draped curtains being so effective; perhaps I might settle for the blinds, and add some curtains for decorative effect. I can pay $3000.00 if they will achieve the insulation I need.