The easiest and cheapest way to insulate your windows is to apply weather stripping around the window frame, which seals gaps and prevents drafts, making it a simple and affordable solution to insulate your windows.
Other inexpensive options include:
Caulking:
Sealing cracks and gaps around the window frame with caulk is another easy and cost-effective way to insulate.
Window insulation film:
A plastic sheet that can be applied to the window and shrink-wrapped to create a tight seal.
Bubble wrap:
A quick and cheap option to temporarily insulate windows by sticking bubble wrap directly onto the glass.
Thermal curtains:
Thick curtains can help block drafts and provide additional insulation.
Draft stoppers:
Placing a fabric tube filled with insulation material at the base of the window to block air leaks
