Energy efficiency


How can repairing my old windows possibly be more energy efficient than new replacement windows?

1.  We add weather-stripping to your wood windows, which reduces air infiltration 70% (results of blower-door test).  Combine that with a good storm window and you also protect against conduction and radiation of heat and cold.  1″ to 2 ” of air space between the window and the storm is much more effective than 1/4″ to 3/8” found in typical double-glazing.

2.  Your repaired and weatherized windows will last as long as your home does.  Replacement windows are not built to be repaired and will have to be replaced AGAIN in 25-30 years.  By that time, the company will probably be out of business.

3.  If your house was built between 1915 and 1940, you probably have multiple lites in the upper sash and possibly even the lower sash.   Double-pane or insulating glass won’t help you (only works if the lite is over 24″ square), it’s just expensive and will have to be replaced in anywhere from 15-25 years due to the breaking of the seals between the panes of glass, causing condensation or cloudiness.

4.  You have not thrown all of those sashes into the landfill.

5.  Your money has stayed with local small businesses instead of going to large out-of-state corporations.

6.  You have not paid for the shipping of all the replacement windows, wasted gasoline and contributed to climate change.

7.  You have not paid to harvest/mine and to process the resources to make replacement windows (wood, plastic/petroleum and a little metal in the hardware).

8.  FINALLY, you will get a return on your investment (ROI) as follows (The Old-House Guide p. 56):

a.  Storm window over single-pane original window, ROI = 4.5 years

b.  Double-pane thermal replacement window, ROI= 40.5 years

c.  Low-e glass double-pane thermal replacement, ROI = 34 years

d.  Low-e double-pane thermal replacement of window with storm = 240 years!