If your apartment's walls are cold, then up to 33 percent of the heat you pay for is escaping.
What's the dealio?
Back in the day when home heating costs were cheap, insulation, which is important for regulating indoor temperature, wasn't a building code requirement. In fact, overheating apartments was once a standard winter practice due to heat loss from the lack of insulation.
Wall tapestries are an easy decor fix that will warm up walls. The heavier the material, the better. A quilt will also work.
Tip: A fabric feature wall will also warm up cold walls. It's an easy DIY that uses liquid starch to apply cloth. However, unlike traditional wallpaper, starched fabric is a cinch to remove, so it's a good project for both renters and commitment-phobes.