Top down bottom up blinds? They come with an aluminum coating too (to block sunlight and thus heat). In our bedroom we installed 2 roller blinds on top of eachother. Both white. One translucent for privacy and one to darken the room. It was cheaper that the dual layered (cellular) blinds and I did not want foil. Not sure if you'd have the space for that (we insulated the walls from the inside, so our window frames are quite deep).

Clear any shrubs / trees / weeds, away from around the house - not saying go out with a chainsaw and slash everything down to the ground but make sure there is nothing higher than the window frames directly around the house or even leaning on the house. Taller tree's may be able to be pruned to allow more light through e.g. lift the bottom of the growth up higher by removing lower branches or thin out branches from within the canopy. Bring in as much sun as you can during the day. If you are planting a new garden, always look at the height of the tree's when they mature and if possible mix some trees that lose their leaves in winter so you obtain maximum sun. Check your insulation e.g. last year I added a new layer of insulation onto of my existing ceiling insulation. If you have dampness under your house maybe look at channelling water away from the house with what ever means you can afford e.g. professional drains right around the house or just dig trenches. You may wish / need to add black plastic over any clay / ground under your house if you are not on a flat concrete block based house. Open curtains during the day. Dress to the conditions. If you can't afford to heat the entire house just heat the room(s) you are using but make sure the non heated rooms get ventilation from time to time (especially lovely sunny days). Pile the blankets on the bed and even use a blanket over your legs if you are sitting watching TV or working on your computer. Think SUN SUN SUN. If you are renting and the house you are in gets very little sun, now is the time to start looking for something that gets more sun. Winter is the best time to look.

Thanks very much for all your feedback. Just to answer a few queries - the deck is directly outside the main room so the new doors open out onto it. The doors won't be French - they're just the only doors that the 3D planner I'm using had, they'll actually be large stacking doors. I've had another idea too which would be a lot more expensive but offers a completely different approach. This is quite rushed so doesn't show accurate layout of kitchen or anything like that, basically just provides an idea. Thoughts!?

Hi, I would like to know how to insulate concrete walls or atleast make the walls look good. All internal and external walls are concreted block built and are exposed, only painted. Thank you so much