Weather-stripping

You can use weather-stripping in your home to seal air leaks around movable joints, such as windows or doors.
To determine how much weather-stripping you will need, add the perimeters of all windows and doors to be weather-stripped, then add 5%–10% to accommodate any waste. Also consider that weather-stripping comes in varying depths and widths.
Before applying weather-stripping in an existing home, you need to do the following (if you haven't already):
• Detect air leaks
• Assess your ventilation needs for indoor air quality.
Selection
Choose a type of weather-stripping that will withstand the friction, weather, temperature changes, and wear and tear associated with its location. For example, when applied to a door bottom or threshold, weather-stripping could drag on carpet or erode as a result of foot traffic. Weather-stripping in a window sash must accommodate the sliding of panes—up and down, sideways, or out. The weather-stripping you choose should seal well when the door or window is closed while allowing it to open freely.
Choose a product for each specific location. Felt and open-cell foams tend to be inexpensive, susceptible to weather, visible, and inefficient at blocking airflow. However, the ease of applying these materials may make them valuable in low-traffic areas. Vinyl, which is slightly more expensive, holds up well and resists moisture. Metals (bronze, copper, stainless steel, and aluminum) last for years and are affordable. Metal weather-stripping can also provide a nice touch to older homes where vinyl might seem out of place.
You can use more than one type of weather-stripping to seal an irregularly shaped space. Also take durability into account when comparing costs.