How can I insulate my room cheaply?

You can insulate a room cheaply without a full remodel by focusing on air sealing and low-cost materials that stop drafts, which account for up to 40 percent of heat loss. Start with the cheapest wins. Apply removable window insulating film kits, which cost $5 to $10 per window and create a dead air space like a storm window. Add heavy thermal curtains or moving blankets over windows and exterior doors at night. Use door draft stoppers or a rolled towel under doors and apply self-adhesive V-strip weatherstripping around door and window frames for $5 per roll. Seal electrical outlets and light switches on exterior walls with foam gasket inserts that cost pennies each. For walls you cannot open, hang tapestries or thick rugs on cold exterior walls to add an R1 to R2 buffer and make the room feel warmer. If you have access to the attic above the room, buy a few bags of blown-in cellulose or fiberglass and rent a blower for free from Home Depot, which can raise your attic from R19 to R38 for under $200. For a single room, rigid foam boards like 1-inch EPS at about $10 per 4x8 sheet can be cut and friction-fit against a cold wall behind furniture. Finally, use a tube of caulk to seal baseboards, window trim, and any penetrations where plumbing comes through walls.