If I'm seeing it correctly, it looks like the ceiling is flat and just the window tops are angled, yes?

I would consider doing motorized shades...one that is a sun shade and one that is room darkening from the ceiling to cover the whole window. They will give you good protection from the cold and the sun.

You could then add side panels of fabric and a valance across the top to hide the works. The hem of the valance can be angled like the top window.

Or you could ignore the angle and just do rod and drapes from the horizontal mullion, but that won't help as much with insulating and light control.

You can have angled window treatments made

First of all, what an awesome view! You said you're thinking of a film for privacy - I assume you mean some kind of exterior reflective surface? Obviously you don't want to frost these windows and lose the view.

If Annie is right and this is a level ceiling with slanted windows, I also recommend going parallel with the ceiling. There are insulated curtains that can buffer the cold from the windows. However, for them to be really effective you will want to keep them closed most of the time.

Find out if there's a draft from the windows - they may need to be resealed. If they're just cheap single-pane, there may not be much you can do about it. But if these are modern, double-pane windows, you shouldn't get a lot of cold air coming off them. It may be they weren't insulated correctly when installed or there is a leak.

I hope this is helpful. Good luck!

Thanks so much for your comments and ideas. Sadly the ceiling is sloping and the windows were made to follow the slope of the ceiling. The left side measures 10'9" (328cms) and the right side 8' (244cms). Overall width of all the windows is 17'7' (530cms)

The film is going to be reflective on the outside so we still have all the light coming in but not the glare and when the light is off we will have privacy. Sadly the windows are double glazed but really poor quality, cheapskate builders!! I have had them re-insulated twice but it does not work. One day I am going to have to pay for them to be replaced but it will be very expensive.

I was thinking this could be a solution in the meantime!

Thanks Chrissie

What may work then is to do the honeycomb shades...you'd have to have custom for the angled window above and then do rectangular for the windows below. The top would need to be motorized. But they will help insulate.

I have large (9 foot X 41/2 foot) windows on a high floor with tons of wind and it is freezing. Glass, double even triple paned can only do so much. I have added white pleated black-out honey combed shades. They do make a great difference. What I found though is when the wind is whipping through as in yesterday's blizzard air sneaks around the edges, and curtains on top really help. I have simple sheers over the blinds and even that little bit of fabric makes a difference. What I like about the blinds is they disappear when pulled all the way up. Good luck and what a beautiful home and location.