Helpful? 0

Double storm panel on French doors?

I live in SE PennsylvaniaI, recently rather frigid winters.

I purchased a house with 13 South-West East facing exterior double french doors (26 doors in all) representing about 100' of wall space around a U shaped courtyard. Yes, I am aware that it is over the top, but I didn't build it - I just acquired someone else's mistake. Spectacular on temperate sunny days, but expensive to operate otherwise.

The doors are about 25 years old, in good shape for the age, single paned with a detachable storm pane with about 3/4" of air space between glass. Attached is a picture.

I need to get better energy efficiency and am thinking about adding a second detachable storm panel with another 1" of air space if it would give me a significant improvement. It would cost about $5,000 to do all the windows.

Replacing with new doors would be extremely costly, but I would be prepared to do as well it if it's the only course of action to get better efficiency and comfort, although I don't expect it would be much of an improvement energy-wise.

Appreciate your counsel on this-


Asked by John Metzger
Posted Mon, 02/03/2014 - 19:39
Edited Mon, 02/03/2014 - 20:48


5 Answers

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Helpful? 0

There is no simple answer to your question. If this were my house -- a house with 26 exterior single-glazed doors -- I would begin removing the doors and framing up the openings with studs and insulation, and I would fill in as many of the openings as possible with drywall and siding.

If you can only afford to do one or two doors a year, that's what you should do. After 13 or 26 years, you'll be done.

Of course, another option is to add the additional storm panels. But you will still have a huge area that has a very low R-value and lots of air leakage.

Answered by Martin Holladay, GBA Advisor
Posted Tue, 02/04/2014 - 10:27

Helpful? 0

I didn't see any picture attachments, which may provide enough clues for further suggestions.

If the seal on the detachable sashes to the main door is fairly good you can probably just re-glaze the detachables with a low-E hard coat glass for something like $50-100 per door, boosting performance from about U0.5 to about U-0.35. (That is about what you would get by adding a third pane of clear-glass, but at less than half the cost. Hard coat low-E detachables will still offer reasonable solar gains, and has a minimal impact on visible light. You may or may not be able to figure out how to get Larson Insiders to fit as one possible solution:

Larson storms are widely available through the box store chains, but any decent local glazier should be able to quote you on re-glazing your detachable sashes with low-E single pane glass, which may or may not be cheaper than the box-store low-E interior storms. For sure it would be least amount of work & risk if you can just re-glaze the existing sashes.

Answered by Dana Dorsett
Posted Tue, 02/04/2014 - 18:36

Helpful? 0

Thank you both for your advice, which has brought clarity to this. Because of the design of the house, my choices are either to replace with the same at a huge cost or do the fix with the storm panels. Reglazing the existing storm detachable with Low E will save me only $50 per or so over a separate, additional panel, so I am going to go with the additional storm panel, but using the Low E glass. This will give me the additional advantage of being able to cover the entire door, and not just the glass part.

Answered by John Metzger
Posted Tue, 02/04/2014 - 21:01

Helpful? 0

People love glass, but there are ways to get the look without as many square feet

My house has a stupid amount of glass, but not as bad as some built in its style. My living room overlooking the deck has 2, 8 foot wide windows and one 8 foot slider. Many similar houses have sliders the whole way. Not only are my windows fixed glass so they do not leak as a slider[or french door] would but they of course are smaller.
They could be smaller yet without changing the look. The sill is 30 inches from the floor, yet when you look out the deck rail is six inches tall and ends at 36 inches, so if the window was 6 inches further from the floor I would lose no view, as I am just staring at the side the deck rail now.

My point is that any glass above about 6 feet provides no view, any below your eye height when seated provides no view. Assuming there is something to look out for the entire width you could diminish the amount of glass by half without actually losing any view.

Walls are so much cheaper than windows you could easily eliminate a huge amount of wasteful glass for not a ridiculous amount of money, and buy superior insulating windows in the bargain.

If you actually need the egress, choose a high quality full light single door rather than an expensive french door unit

If you 'corrected' one wall at a time it would not be cost prohibitive

Answered by Keith Gustafson
Posted Tue, 02/04/2014 - 22:28

Helpful? 0

I'll bet that you have a significant amount of the heat loss around the edges of the doors. You need to get rid of these doors. If they are necesary then make them fixed with wood stops and sealed and caulked edges. Better yet, replace with similar size new double glazed fixed windows which match the door glass in size.

Answered by Bob Irving
Posted Tue, 02/04/2014 - 23:26

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