Old houses with windows that aren't updated can be very draughty, allowing air to escape and resulting in higher utility bills. According to the BBC, one fifth of a home's heat is lost through windows and if those windows are single-glazed, they lose 14 times more heat than an area of wall space the same size. Secondary-glazing your windows is an affordable way to add another layer, resulting in less draft and a potential savings on your utility bills.
Clean the area around your window and frame with a mild solution of dish soap and water to remove any dirt. This creates a better surface for the tape to attach.
Attach a layer of double-sided tape around all four sides of your window frame.
Measure the window from the top of the double sided tape above the window to the bottom of the double sided tape below the window. Repeat this process for the width of the window as well. Write the numbers down.
Cut a piece of clear, heavy duty plastic sheeting to the size of your measurements.
Affix the cut plastic sheeting to the double sided tape so that the original window and frame are covered. Pull the plastic as tight as possible.
Repeat the process for any window in the house that needs secondary glazing.
This process illustrates the simplest way to create secondary glazing and usually lasts for one season. If you are a highly-skilled carpenter, there are permanent forms of the glazing to create. Professionals will also install permanent forms.
Once you install this form of secondary glazing, you will not be able to open your windows. If opening them is important to you, talk to a professional who can design and install removable versions.