Any door or window with access to outside should have any drafts sealed up. There are many options to cover your windows and doors and help keep the heat out and the warmth in.
Effective seals around doors and windows are a really good start. This is something that can be done for any rental property
Older style houses often have issues with drafts under doors. You can make door snakes to fit the space. Filled with clean sand, you can make them as big as you need and they won’t move.
Window Covering Alternatives
Bubble wrap is a very cheap and effective way of insulating windows that are not used frequently or if you are in a rental. Just spray the window with water and apply the wrap with the flat side to the window.
Hanging a piece of fleece, blanket or duvet over a curtain railing over a are also a great form of insulation.
Blinds are another form of window covering. Honeycomb blinds are the most effective but you can add another layer to what you have to keep the warmth in.
There are many options when it comes to making curtains. The most effective have multiple layers with thermal backing material and a pelmet. If you don’t have a pelmet then having your curtains reaching the ground will stop the air flow. Don’t forget doors with glass as these need to have some form of covering too. You can also use curtains to close off rooms when you don’t have a door. This means you are only heating the area you are using.
Curtain blankets are another option for windows and doors. You can instructions on how to make one at How to Make a Window Blanket