Cheers, yeah ducted makes sense. But a floor mounted model I think, at least based on the layout at the end of our hallway, would certainly work. It was still $2k though. That covers a lot of nightly oil heater running costs over a long period. I've asked a mate who installs joinery to get me a price on double glazing the kids rooms instead. Obviously not a method of heating, but better heat retention may just be enough to take the chill off. It certainly helped doing double glazing on a large window in our stair well. Think I'll stick to oil heater for the time being as we're in the process of putting a pool in ready for summer so that in itself is a v. large expense!
PVC double glazed windows just cost me around $1600 each installed (ish), using the existing wooden frame and an "insert" method. Replacing the frame costs around $500 more and more time painting.
Size of window? Got mates rates on mine, about 1200mm high by 2100mm wide for less than half that installed (aluminium, so likely less labour than timber)
A variety of sizes. Most will be around 3x2 meters made up of one large pane and two smaller panes, one of which opens. Some are a bit bigger, some are a bit smaller. My prices include fitting, but not the touch up painting work that was required.