Replies

1. 
   [email protected] | Dec 26, 2013 01:33pm | #1

   Good afternoon Mike,

   If your current single pane windows are still structurally sound and your primary concern in replacing is payback thru energy savings, then you almost certainly will end up with a better ROI by first tightening up the existing windows (replacing weatherstripping, etc, as needed), then adding storm windows.

   Better quality replacement windows incorporating LowE coatings and argon gas offer improved energy performance, will save you money, and they will make your home more comfortable, but they won't pay for themselves in a "short time" regardless of what you have been told, unless your existing windows are pretty much junk.

2. 
   mswsf | Dec 26, 2013 03:14pm | #2

   Thank you - the single pane windows need to be replaced. The contractor helping us would use HD windows (probably American Craftsman) or suggested Marvin Infinity as a step up. We could also source otherwise.

3. Expert Member
   Dana Dorsett | Dec 26, 2013 05:27pm | #3

   A Marvin is likely to leak less air, have better/more reliable weather stripping, and have better hinge/latch/slide hardware. The payback is in the longevity and lower stress of not cursing at the thing regularly after 10 years of use, at equal U-factor, etc.

   In cold/very-cold climates a much lower U-factor than a code-max U-0.35 or whatever pays off in comfort if not short-term dollar savings. But that comfort comes at a price. Still the difference between a U0.35 window and U0.25 window is something that can be felt just standing next to it even at fairly temperate +20F outdoor temps.

   U-factor, SHGC (solar heat gain coefficient) and air leakage, the direction the window faces, and the site shading factors are all need to be taken into account to determine the energy use performance differences. You can download a freebie copy of RESFEN and model it by the numbers, if you like:

   http://windows.lbl.gov/software/resfen/resfen.html

   If the single-panes are reasonably tight (and don't have lead-paint issues forcing their replacement), you can get more performance out of a tight low-E storm window than replacing the existing window with a bargain-basement code-min replacement window. Harvey makes the tightest storm windows in the biz and have a hard-coat low-E glazing options. The Larson low-E storms distributed by box stores don't totally suck either, if you upgrade to the "silver" or "gold" versions, which are significantly tighter and have nicer hardware than the "Bronze" flavor.

   http://www.harveybp.com/product.aspx?pid=1

   http://www.larsondoors.com/storm_windows/products/gold_series/

   With a low-E storm over a wood-sashed single pane the combined performance is in the U0.30-0.32 range, at an installed cost well under that of a bargain basement replacement window.

4. GBA Editor
   Martin Holladay | Dec 27, 2013 07:15am | #4

   Mike,
   Q. "How do I determine if/when [replacement windows] will pay for themselves?"

   A. According to Michael Blasnik, an energy expert who has crunched the numbers, “Window replacement has a 100- to 300-year payback.”