Interior Storm Windows
I first created these storm windows back in 1997, for an old victorian house I owned. When I moved to Maine, I introduced these interior storm windows at the 2nd Annual Midcoast Sustainable Living Expo, which was sponsored by the Midcoast Green Collaborative and they have been modified, improved, tailored, and run rampant since then. We estimate that over 20,000 windows have been made by, and for, Mainers since then, and there are groups now in other parts of the Country, and in Hungary and England making them.
The Design
picture credit: Guy Marsden
The idea of the windows is simple. A wooden frame is made about ½ an inch smaller than the window frame it is to go in, and that frame is covered on both side with pieces of heat-shrink (polyolefin) plastic. Tape is used to cover the edge, the film is shrunk with a hair dryer, and a ½ inch foam weather stripping is added around the edge. The storm is then inserted in the window frame for the winter, and removed for storage over the summer
We generally make these storms with pre-primed pine, but most any wood will do, provided it is structurally sound. Scrap or #3 pine is fine for basement windows for example, or using clear wood, or painting the wood to match the existing trim, will make the storms even less conspicuous.
Simple instructions or a 2 page PDF version.
An exhaustive website with pictures, material suppliers, and a spreadsheet for material costs by Guy Marsden.
Here is a Google Sketchup plan for the storms, and here it is on the Google 3D Warehouse. Hiding various components will allow the construction details to be discerned.
The Benefits
picture credit: Guy Marsden
Interior storm windows have an R-value of around 2.3 and will reduce the air leakage from a leaky window. They also reduce outside noise. However, they do reduce the amount of incoming solar heat (SHGC 0.86), which while not a benefit in the Maine (and many other places) climate, it is a reasonable compromise, and the storms on a whole are a benefit. For cooling dominated climates they are always a benefit.
The actual benfits you get will vary depending on your climate, cost of heating fuel, and type and condition of your windows. But broadly, if you have single pane windows (and no storms), the simple payback time will be under 7 months. In other words it is cheaper than buying fuel this year. And the benefits will continue for years to come. For single pane windows with aluminum storms, the payback is around a year. For good double pane windows around 2 years. For Andersen energy-star rated lowe-4 windows, the payback is still around 4 to 5 years. Only if you have super high-efficiency triple pane, lo-e, gas filled windows (or better) do these storm not make good sense.
Workshops
Other workshops
If you are running a interior storm workshop, we would love to hear about it, and will gladly put the relevant information here.
Buying Interior Storm Windows
Green Fret Consulting makes these windows, To see about ordering from us orfor an estimate. We also make a triple pane version for increased insulation value and for larger windows and skylights. We now ship window kits, and windows less than 39" x 63", anywhere in the US.
If you are making these interior storm windows for sale, we would love to hear about it, and will gladly put the relevant information here.
Other News
This is a local TV News report on some volunteers making these windows for low income and elderly homes.
This is a sing-out from Bill McKibben at 350.org