Energy Efficiency Part 1) old windows and doors vs. new


Airplane Bungalow Shed Dormer, Row of Historic Double Hung Windows (Circa 1910)


Keep my old windows and doors or replace them with new windows?  Where I live in Southern California, we have allot of historic homes that still maintain the original windows and doors.  Over the past century there have been great advancements in window and door technology mainly focusing on energy savings.  This is achieved by blocking solar transmision and hot/ cold transfer from outside to inside and vice versa.  There are many technical studies on long term cost comparisons of old windows vs. new windows.  Here is one such study; 

http://www.oldhouseguy.com/window-energy-analysis/

In this study they compare a new vinyl double glazed window with a historic wood single pane window/ storm window combination over 100 years.  If you dont want to read the whole 29 page report, here is the conclusion; The 100 year upfront cost and maintenance costs of the new replacement windows is roughly double the cost of the historical window.  This is due to the high upfront cost of the replacement window and the fact that they need to be replaced every 35 years, while the historic windows last for 200 years.  The yearly energy costs are about the same, with the old windows performing slightly better. 



Historic windows last such a long time because they were made from old growth wood.  This wood was typically Douglas Fir or Redwood.  Todays windows are made of vinyl, aluminum or new wood.  The new wood windows are especially problematic as the wood is soft and susceptible to termites and rot.  In order to get the farmed trees to grow quickly, they are injected with hormones and the termites are attracted to this.  


If you have historic windows throughout your home but they are in dis-repair and wont operate properly, I have good news....Typically you can find specialists to renovate historic wood windows for around 450 dollars each.  


Renovated Historic Double Hung Window with new ropes/ weights (Circa 1910)

This includes repairing the locks, ropes, weights and getting them to operate smoothly.  In addition they will add gaskets to reduce air leaks and make the windows more sound proof.


Historic windows are beautifully crafted with amazing joint work, thin frames and sometimes have original glazing as well.  This is what gives them such a highly crafted look.  New window frames and muttons are thicker and less elegant.  I live in a 1910 Craftsman Bungalow. All the original widnows and doors remain in the home except for the addition.  When I constructed the addition, I purchase the very best wood windows you can buy.  These windows have triple gaskets, double glazing and low e glass coating.   Unfortunately, these new windows are hard to open and some of the frames are already starting to get chipped and are showing hairline frame cracks after one year.  Comparatively, every historic window and door in the house was renovated as mentioned above for a nominal cost (450 dollars average).  Every single one of the old windows operate like butter, perform great and looks fantastic.  I love to operate them as well as just sit back and observe the craftsmanship.  So if you have these treasures in your historic home, please do your research and please understand all the wonderful benefits of living with historic windows and doors.  


Double Inswing Historic Window (Circa 1910)

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