Building a double hung window from scratch

One of the biggest problems in our new house is the windows.  All, and I mean ALL, of the windows have been painted shut, caulked over, rotted out, and rendered completely useless in every way imaginable.  Whats most unfortunate is that these windows were likely beautiful when they were crafted back in 1940.  The majority of them are large 8 over 8 double hung sashes with really nice ogee muntin profiles and single pane OLD glass.  As I read and learned more about the beauty and value old windows, I became adamant that my windows needed restoration and rebuilding.  I welcome the challenge from anybody advocating the replacement of beautiful wooden windows with modern vinyl drop-ins (or even modern wooden windows) based on some nonsense arguments about energy efficiency or practicality.

To that end, I began my research into how windows are made, restored, or otherwise repaired.  This included reading some old millwork books and catalogs from the early 20th century.  I’ll post some links to the resources I found most useful shortly.  I also came across a few bold souls who took it upon themselves to make wooden storm windows (for example.)  At the end of the day, I decided to rip out the worst window in my house (which happened to be in the front dining room), and start the 6 month long journey of building an entire window from scratch using rough cut mahogany.  A special thanks to my wife at this point for putting up with a plywood window for so long, and to my father-in-law for his insight and weeks of labor during the “final push.”

I’m planning to document the actual construction of a window over the course of several posts including a few as I proceed with future window work.  For now, let me just present a quick timeline with a few photos to give the basic idea and overview of the project.  Disclaimer:  this was the FIRST major project I’ve undertaken in my wood shop, and I wouldn’t recommend it to be yours!

Let’s start with the window in question.  Here is a shot of it after prying it open through countless coats of paint.  The drywall around the window was also removed since the rot had progressed through the entire sill and down into the framing.

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And here is the window completely removed with the new plywood replacement in place.  The damage of the rot is clearly bad and most sane individuals might have sought professional help at this point.

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Next I started the process of removing the window glass.  This just involved scraping away all of the old glazing and finding the glazing points.  A steam cabinet is in my future to make this easier.  Once I started stripping the paint, I decided that the best route for this particular window was a complete rebuild.

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Sourcing all of the needed router bits and tools / jigs took quite a while.  CMT was a great source for ogee bits that would accommodate long tenons (as opposed to stub tenons which seem to be the most popular.)  For material, I found a local supplier that carried quite a bit of 6/4 and 8/4 Spanish Cedar, which is neither Spanish nor Cedar.  Look it up.  Below, you can see some of the stock cut four square with one of the rails routed with the inside profile.

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Here you can see one of the frame tenons made with my Rockler tenoning jig.  More detail on this will follow in a later post.

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The sash frame uses through tenons on the top and bottom rails, and double tenons on the meeting rails.  The muntins are all mortise and tenon joints to the frame and to each other.  This is probably the most difficult part to get right.

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And here is a completed sash.  I was pretty amazed at how strong and heavy this construction is.

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The sashes were then primed, painted, and glazed.  These steps will require a few posts to go over.  Another big problem was restoring the lintel and window frame.  Here you see a refinished frame, and new sill.  Pulleys were cleaned up and painted.  New brick mold was also made.

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Here the bottom sash is installed and weather stripped with new spring bronze.  New copper chains were used to connect the sash weights.

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And here is  the finished window with both sashes installed.

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Drywalll was reinstalled and finished / painted.  The only remaining steps at this point are to build the inside sill and trim everything out.  Unfortunately, the inside sill is on hold until my bandsaw restoration project finishes up.

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(Added 3/23/2012)– Here is a detail shot of the pulleys, chains (upgraded from rope), and brass stop adjusters.

In conclusion, building a divided light double hung window from scratch in your home shop is entirely doable.  I would also argue that it is cost effective once you get all of the moves down and the jigs set up.  I can’t imaging what a custom wood window would have cost to contract through a millwork shop.  Check back soon for posts detailing all of the individual steps with more photos and info on the tricks and techniques.