Studies suggest the most efficient way to insulate your windows in your home is from the outside first. Putting fabric awnings, or shutters on the outside of the window will stop the heat or cold from hitting the glass and effecting the temperate in your home.
In order of most effective to least effective would be:
2. Fabric Awning. (External blind)
3. Plantation Shutter.
4. Thick Curtain.
5. Dual Roller blinds. (2 blinds in 1 window. 1 blockout. 1 screen)
6. Honeycomb Blind. Thick backed blackout roller blind.
7. Vertical blinds.
With about 40% of your heat or cold coming through your window anything you put on the window will make a difference. Look for where the cold or heat could be coming in from other places around your home. Under doors, ceilings etc. Be aware of where the worst of the heat and cold weather affect your house. Are there certain rooms that getting hotter than others for example.
Here is a short description of some of top styles of the most efficient ways to keep the heat off the window and out of your house.
Choose an external blind/fabric awning first. It is the heat coming from outside your home heating up your window and the residual heat warming up the house. Its best to have the protection on the outside of your window first, and then address the inside. Choosing a lighter fabric that will reflect the heat better, just like a white car is cooler than a black car.
External Aluminium Roller shutters are great insulators. The aluminium curtains are foam filled for better insulation from heat and cold, as well as great insulation against noise. They have the added benefit of being good for security.
Internal Plantation Shutters are ideal for your windows to keep the heat out. Think of your old high school science days and remember how timber wasn't good at holding heat. Timber Plantation shutters and even the premium Thermopoly Synthetic shutters are great for coping with a hot window. Again, choose the lighter colours. Even on a 40 degree plus day a good quality shutter will not warp in the heat.
Honeycomb insulation blinds have little cells within them that hold pockets of air and slow down the process of heating your window. Some of the premium blockout honeycomb blinds are foiled lined for added blockout and heat protection.
An internal dual roller blind has 2 blinds on one window. One blind is a blockout blind, the other a screen blind. The heat coming from the window slows down with the pockets of air in between each blind, adding another layer of protection to your window. Choose lighter colour for both types of blinds, and the thicker the fabric the better. Some blockout roller blind fabrics have white insulated backing for added insulation. A dual roller blind system gives you versatility with your window coverings. You can have one blind up or down at a time or both down for added insulation.