WATCH NOW: Secondary glazing windows with window insulation film.

Windows are the weakesk link (thermally speaking) in the average house. They cause more heat gain and loss than any other area of your home - even when they're closed.

To stop this you have to insulate them - double glazing, heavy curtains or some form of secondary glazing that traps a layer of still air. In this GIY project we insulate a timber sash window with a plastic film called Clear Comfort (this is an Australian product but there are a wide range of similar and cheaper products available in the US).

It is affordable (between $5 and 12/m²depending on the brand), easy to install and really makes a difference.

Trickiness rating: EASY

Fact Sheet

Fact Sheet Attachments

PDF Secondary Glazing.pdf

Shopping List

Shopping List Attachments

Shopping list for Clear Comfort.pdf

Trades

Trades

Comments

Links

Links

http://www.clearcomfort.com.au/

http://www.windowinsulationfilm.com.au/Window_Insulation_Film.html

Top tips and tricks

Window insulation film is tough and durable. Will withstand kids poking but not cats clawing.
Cleans with a microfibre cloth.
Clear Comfort cost around $12/m²
Window insulation film $5/m²
Do this GIY job on a low-humidity day to avoid condensation in the window space.
Request 'temporary tape' with your Clear Comfort kit if you are wanting to remove the Clear Comfort. The permanent tape is forever.
The Wiindow Insulation Film only has permanent tape but offers a 'premium' film which is a bit more durable and robust than it's other film.
Optimal air-space between the window and the film is between 6mm - 16mm. Large spaces are not as good as you get air movement which reduce the insulation.
Secondary glazing such as this window film is second best to double glazing but is often much more affordable.
There are other types of secondary glazing on the market (Magnetite, MagicSeal and ecoGlaze) but most of these have to be professionally installed. These film are low-cost DIY job even if not as gutsy as other options.