I’m a huge fan of insulation. A well-insulated home traps free winter Sun so you don’t need much heating on sunny days, and reduces the cost of heating on those days when the Sun doesn’t do it for you. Insulation also lets you enjoy life more as you’re no longer living within a 2m radius of the heater. Roof, floor and wall insulation can be a big deal though, and even with govt help, requires a significant financial outlay. Double glazing is even more expensive and the payback time is over a decade. But covering the windows in bubble wrap or plastic film, while temporary, is cheap and amazingly effective.
Bubble wrap is the product of choice for any window you don’t often look through. Holding it onto glass with water is quick and will come away cleanly. A more effective method, if you don’t mind a bit of a clean-up job afterwards, is to use sellotape (or even masking tape if you’re worried about the surface but don’t mind the look) to attach the bubble wrap to the frame. The aim is to create an air gap between the bubble wrap and the glass of 1–2 cm.
More is OK, but a greater distance doesn’t improve matters any. The air gap works exactly the same as it does in thousand-dollar double glazing. Yes, that’s what the bubbles are for in bubble wrap, but this way you get double the insulation. Make sure you completely seal the wrap to the window though, otherwise it doesn’t work. Another advantage to sealing the window with bubble wrap is that you seal off any leaks around the window frame.