There are many types of storm windows that you can get to help make your home more energy efficient during the winter. Your budget and how you want the finished windows to look will probably be the deciding factors in what type of storm windows you use. No matter your requirements, this list will help narrow down your options.
Exterior storm windows need to be made from a durable material and properly maintained, as they're mounted on the outside frame of the window and are exposed to the elements. They're not quite as efficient as interior storm windows because a drainage hole must be left to allow moisture to escape. If no drainage hole is provided, the frame of the primary window will begin to rot. For this reason, exterior storm windows can't be made completely weather tight and will allow some energy seepage.
Interior storm windows are the easiest to install and remove, especially if you live in an apartment block or have a multi-story house. Mounting the storm windows internally can be more attractive to people who live in an historic area or those who want to preserve the outside style of their home. They're also more energy efficient than exterior storm windows, as they form a tight seal with the existing window glass. There are many styles of interior storm window to fit any budget.
3. Low Budget Disposable
Some hardware stores sell storm window kits made of plastic or vinyl sheets or a film that can be applied to the windows. This can be an good short term option if you don't have enough money to invest in more expensive storm windows, but offer reduced visibility and will degrade due to the impact of sunlight and need to be replaced. Other kits made of wooden frames with a plastic shrink film that is fitted over them are also available. They tend to break apart when removed, however, so must be replaced each year.
4. Glass or Plastic
A range of glass and plastic storm windows are available for a medium to high budget level. These are normally more sturdy and the metal or vinyl frames are easily installed and removed using a hook-and-groove system. Some metal frames also use magnets to maintain a secure fit against the primary window. The glass or plastic offers a high degree of insulation, although glass tends to have better visibility and is less likely to show any scratches or damage. They can also be tinted to offer protection to furniture from direct sunlight during the summer months.
Storm windows should not be confused with casement windows. Casement windows are a type of window system where the window swings on a hinge and is operated using a crank inside the house. Although some types of casement window have an external shutter, they are not as weatherproof as a storm window. Some types of interior storm window can be installed in casement windows to increase their energy efficiency.