All About Historic Windows

By Scott Sidler • October 22, 2011

4 pane casement window

For me, windows are one of my favorite, and at times, most challenging  (they’re one of the few parts of a house with lots of moving pieces!) aspects of a classic home. Windows truly are the eyes of your home and I have seen too many homes with a black-eyes over the years. A home and its occupants look out onto the world through these sometimes simple, sometimes complex contraptions to keep out the elements and let in the light. And the world learns a lot about your home by its windows.

A Brief History

In the first homes, windows were more than a decorative way to light the room. Originally, there was no glass, simply a crude opening designed to let fresh air in, smoke from the family’s fire out, and light the space. This lack of glass was the reason for the first shutters. After all, you didn’t want a hole in your wall during a rainstorm or a brutally cold winter, not to mention all the bugs. Eventually, glass came into the picture. First for the rich and the nobility and then slowly to rest of the masses.

Up until 1900, all glass was handblown and large pieces were very expensive. The expense and relative unavailability of large pieces of glass resulted in windows with several “lights” (meaning individual panes of glass) being the trademark of the days. In 1900 a new technique was invented and the predecessor to modern glass, called machine-drawn glass, was born. Hand-blown glass was mainly good for letting light into the room as the images seen through the glass were usually a blurry mess. Machine-drawn glass greatly improved the clarity and consistency of glass but was still far from perfect. As glass making skills increased, the size of individual panes increased as well resulting in new combinations such as 6-over-6, 4-over-4, 3-over-1, 2-over-1 and eventually glaziers could construct a window out of a single pane of glass.

Windows are typically described by their number of panes (6-over-6 has an upper sash with 6 panes and lower sash with 6 panes) and by the way they open (ie. double-hung has 2 sashes the open independently of each other whereas a casement window swings in or out on hinges).

9 over 9 double hung windows

In 1959 modern glass, which is the type still used today, was invented and glass could be had in almost any size with a uniform thickness and flawless clarity. But those of us who like the special “glimmer glass” in our old homes that was the day windows with character began to die.

What Kind Do I Need?

Today you can buy windows in more forms than our forefathers could have imagined. Double, triple, even quadruple-paned windows filled with inert gasses like argon to prevent heat or cold transfer. They have become an efficient part of the house, yes, but when dealing with a classic home from generations past, an out-of-place window from the wrong time period can destroy a beautiful facade. Windows of yesteryear each had a purpose and served a function. For example, double-hung windows were designed with an upper and lower sash that could be opened independently of each other. The top sash (which on most older homes has been painted shut over the years) was designed so that in the days before air-conditioning, warm air could escape from the house and be replaced by cool air entering from the bottom sash.

The anatomy of a window (courtesy Old-House Journal)

Pre-war windows were also glazed with linseed oil putty to make the panes airtight. Caulking may last for years, but it doesn’t come close to the 80 year life span of properly cared for glazing putty. Also, being made from old-growth timber, original windows are surprisingly rot-resistant. I’ve had to completely rebuild only 2 windows out of the 32 on our 1929 bungalow, and those 2 were the only non-original windows in the house! The 2 replacements were a mere 20 years old before they succumbed to the elements!

So, before you decide to replace your drafty old windows, stop and think. They can be restored to their original appearance, working condition, and efficiency with period weather stripping (copper not foam or rubber.)

If you’re not sure about whether your windows are candidates to be saved, visit our resource page on How To Restore Old Windows

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62 thoughts on “All About Historic Windows”

  1. I have an old sash style screen frame for my kitchen window that I am sanding to repaint. I removed the little handles to make this job easier. There also was a strip that was screwed onto the top outside edge that I thought was a strip of wood but found it to be a piece of metal that is flat on the backside and rounded on the front or outside. Can anyone tell me what or why this was on there and if it’s necessary to put it back on once I have it all repainted ? This window is original to the house that was built in 1952. It gets set into place under a widow frame the same size above it. Thank you in advance for any help you could send my way, Scott

  2. Have 1820 white Brick Farmhouse…3 bay with center front door with transom. Want to replace vinyl windows with original style but not sure of how many lights: 2 over 2, 4 over 4, of 6 over 6?? Read that 2 over 2 started 1880’s but don’t know what would look good.. Checking out Marvin windows but husband said he might make them. He is very talented! Just not sure what color to paint sashes.

    1. Jo – I have an 1825 twin chimneys colonial farmhouse. Went to a workshop on old home restoration and learned that this era homes would have had 6 over 6 windows. Mine have been replaced with 2 over 2s. Would love to restore back to 6 over 6s, but dreading that little chunk of change – many windows. Good luck!

  3. My four square home was built in 1879. It has most of the original windows except three that are gastly and cheap. Where can i find replacements that are wood, double hung, 2 over 2 in MN? I am considering adding a double hung window in the kitchen with 6 over 1. The window would be the only one on the main floor in the back of the house. There is one window upstairs that is original 2 over 2. Do you think that would that look out of place? Thank you!

  4. Hi –
    I’m restoring some windows and can’t seem to figure out the purpose of one of the parts. My stops have an extra stop on them but only at the lower/inner sash. They don’t touch the sash (~1/4” gap). It’s very simple and doesn’t seem decorative in any way. Would anyone know the purpose? I was thinking maybe it’s a channel for a screen to slide down for the lower sash when it’s open.

  5. Scott can you give me an idea of the age of these windows, first floor Chestnut log house Looks like second floor added later, that is all mortise and tendon framing with plaster lath. The windows are 6 over 6 handblown with mullions that are very thin about 5/8 thick, very elegant. As you can see I have installed interior storms and several years ago I put in copper window sills. We are in Lancaster county PA and the house is located on the Conestoga river along what used to be the main native American route to Philadelphia. I am told that our area was the second area settled around 1720 by French Huguenots.IMG_9337.JPG IMG_9338.JPG

  6. Dear Scott,

    I’m trying to date our craftsman style home built somewhere between 1900-1920’s. The Windows are 3 over 1 pane. The living room has 3 windows side by side with (3 over 1) with woodworking around them. The Windows have strings with weights. Any idea on the production date?

    1. Denise thanks for posting this. I have the same configuration in a home I am remodeling. I know it was built prior to 1925 an have found a Sears Modern Home plan from the 30’s which is identical but have been interested in the 3 over 1 window age. I hope Scott will shed some light for us.

  7. I have a house in Cammack Village (Little Rock), Arkansas. Cammack Village was developed shortly after WWII. My house has the original single hung windows but instead of weights there is an aluminum channel with a spring. I have salvaged a couple of Windows from a house that was being demolished for a new build. I am trying to find a replacement for the channel and spring system. Any ideas?

  8. Just came across this site in my search for information on some 3″ x 3″ prism glass window panes that are leaded in steel frames. there is an area of my newly acquired store front built in the late 1800’s above the full width display windows and two entry doors 42″ high by 20 feet wide of this window glass. The panes have a sleight lavender hue and were all painted over with several coats of paint both inside and out. The outside is covered with a sign at this time and it was only on stripping the interior that this was uncovered. There are two opening tilt panels roughly 24″ x 24″ that I removed prior to insulating the rest of the wall and covering. Wondering if any one has ever seen this and if there is any information on it. The building is in Jamestown, ND and has had several renovations over the years and I’m in the process of another. It had been a Pharmacy since it was built and writing on the plaster wall behind some built in shelving from 1906 suggest it had just been renovated at that time on the main floor. These shelves I just moved in 2017.
    On another issue I renovated a home in Luverne, ND and found a Blue marble embedded in the hardwood floor centered below the living room picture window. The room had been carpeted in 1959 from the writing on the back of the carpet. This house was built in 1916.
    My son just purchased a farmstead near Ypsilanty, ND and on taking up carpet of the 1970’s found a Blue marble in the hardwood floor between the kitchen and dining area.These houses are nearly 100 miles apart so do not think it would have been a builders mark. None of the local carpenters have memories of seeing this on any of their renovations. Wondering if you have ever heard of this, maybe as a trademark of the craftsman doing the original construction.
    Thanks for your time and I look forward to viewing this site often.

  9. I need some advice! We are about to embark on the restoration of an 1890’s farmhouse and plan to restore the windows. The house had a summer kitchen added on at some point that is now falling down. It’s more like a shed attached to the house. We plan to tear it down and rebuild it in the same footprint. I would like to replace the existing single sash/non-opening windows with operable salvaged windows. Do you have any good resources or advice on how to build new window frames for old salvaged windows? The internet seems to be severely lacking in resources when it comes to reusing salvaged windows in this manner. Thanks in advance!!!

    1. Try Salvage companies like Habitat for Humanity. It is quite trendy to buy furniture, windows, doors, etc from “deconstruction” companies.

      1. Thanks Catherine. I love our local Habitat’s Restore, they are great! But what I can’t wrap my brain around is how to frame out the new opening for the sashes that I end up with since I’ve not yet found salvaged windows still with their frame. And I’m struggling to find diagrams available showing the details. I guess once we dive into the existing windows I will be able to use those frames as a guide and figure the rest out from there. But the planner in my is trying to anticipate any issues that might arise from attempting this.

        1. Jen, I am trying to do the same! Please let me know if you find a resource. I have the windows. Just don’t know how to build the frame.


  10. Hi,
    We have a 1904 historical building need to replace the wood windows to keep its historical statues .. Any suggestions for collingwood or toronto in ontario canada area for restoration of the windows.

  11. We are restoring an 1880s farmhouse which originally had 2 over 2 double hung sash which were removed and replaced with the typical cheap replacement windows which we rejected out of hand. We now have 20 brand new sets of reproduction line sash, made complete with through tenons, for all joints by a Mennonite wood shop in central L.A. and the work was absolutely top notch. We will have them all glazed by a local glass company and they will use old wavy glass.
    We also wished to track down the original sash stays (or sash locks), a strip ofvspring steel with a button the you press in to the left side jamb to lift and then place the lower sash as notches on the sash left edge are met. We learned from the antique hardware dealer that they are called Hammonds, ie, made by the Hammond company in PA FROM AROUND 1860 TO 1890. This has been utterly fun, fascinating, and satisfying to go so authentic and thorough!

  12. We have purchased a 1952 California Spanish Bungalow. We have steel casement windows set in the concrete blocks of our home. We are looking to upgrade the windows. Do you have a suggestion on how to go about that? It seems as though I am having a problem finding the information I need to replace or repair them. HELP!!!

  13. We are building a French country style house but trying to make it look like it is from early 1900s. I was thinking of doing 9lites for top and bottom sashes, would that be historically accurate? If not, what do you think would?

  14. Good day

    I have Sash Windows from a old building that i wanted to make photoframes out of. i dont know what they are worth.

    each sash has 9 windows.

    can you tell me more about the history and from which era they are from.

  15. I am restoring a 1790 stone farmhouse in Bucks County PA and am building 9 over 6 sashes for the first floor windows that were retrofitted with 2 over 2 sometime in the late 1800s or early 1900s. I see 6 over 9 and mostly 9 over 6. is one right and one wrong or were they both used? also looking for design details about how the meeting rails came together. I am using an old ovolo sash plane that was from the early 1800s that matches nicely the sash molding on the upstairs windows…

    1. Wow! Building new sashes and doing it with a sash plane to boot!! Well done! As for the lite pattern 6-over-6 and 9-over-6 were both common and it just depends what was originally done. For that age home more and smaller lutes is likely a better plan, but without pictures or old sash it’s hard to know what was there before. Keep in mind too that 1790 sash were likely less than 1 3/8″ thick unlike the sashes from the mid 1800s and later.

      1. Thanks Scott. I am making them thinner than what was there.. a bit thicker than the upstairs, a bit over 1 inch. the question was 9 over 6 vs. 6 over 9, you may have misunderstood me… the combination fits in the opening perfectly but I have not been sure which should be on top!

        1. Both are historically accurate so there’s no real way to tell. I would look locally to any other buildings the same age and see what if anything was typical in your area at that time.

  16. My 1910 Classical Revival bungalow possesses remarkable historic integrity in most respects. Unfortunately, the original double hung sash (and wavy glass!) was replaced with aluminum in 1984. Fortunately, the original casing remains intact. My house was built by the first generation of an African American family to be born in freedom. It is modest in size, fewer than 800 square feet, but it has style. The four doric columns that support the porch roof are called out specifically in the NRHP listing for the Tenth Street Historic District (Dallas). The house has only eight windows. The four largest of these are 30″ wide by 78″ tall. Any ideas as to what the original glazing pattern would likely have been? I assume each sash would have measured 30″ wide by 40″ tall with about 2″ overlap when the windows were closed. I would like to restore my home with vintage sash and wavy glass, but I think the height of the windows may pose a challenge. Suggestions?

  17. I live in historic Nazareth, PA I have 34 sashes from a 1929 home to sell. White on the outside..natural stain on the inside.

  18. Hello. I just purchased a very old Awning Window (Transom?). It is very old, cased in wood with hinges and the name: Pine-Hurst and below that is the number *503*. Do you know anything about these types of windows? Would this be the address or name of business/law firm? Thank you for your time-Amy

    1. Not sure, Amy. It might a model and model number of a company’s window. If it’s newer than 1920s that’s likely the case. Otherwise it might take a little more detective work.

      1. It is actually painted on the glass. Sirry, I should have been mire specific. It is painted in bkack, Pine-Hurst then underneath that is the number *503*. It’s not in the gold leaf letters that you typically see. It is in black. Thank you! Amy

  19. we are about to restore a 1929 bungalow in Birminhgam AL. Unfortunately all the original windows have been replaced with cheap ones. Where can we find old windows to replace the replacements?

  20. The windows in our 1843 house do not have weights. Instead, they have pegs in the sides that fit into holes in the frame to keep them open. The glass is very wavy. Do you think these windows are original to the house?

      1. Thank you. House was just purchased in summer of 2015. Trying to figure out original layout of rooms. Good to know the windows are original.

  21. Just started restoring original windows of our house built in 1900. The first window that I’ve started stripping has revealed a jet black charcoal-like coating under the paint. It’s not coming off easily. What is this and how do I remove it?

  22. Dear Scott
    All i need are the 2 windows no frames no sills no hardware as they will be permanatly fixed as they were when the carriage house was built. I just need to know how much each window will be with the shipping cost.

    Thank you

  23. i would need 2 please or name of company that can make them the local lumber & window companies are suggesting plastic replacements & that just will not work for this beautiful old building.

  24. I am restoring a 1709 home & the carriage house on my property has 9 over 6 windows. i am looking for 2 of them. i have the antique glass just need the windows.

      1. the 9 over 6 windows that i am talking about have been weathered by time & they have rotted in place so i need to have new ones made. i have the dimensions for each window. the height for the 9 pane is 30 1/4 height & the width is 24 3/4 & the 6 pane is 21 height & the width is 24 3/4. I have a phenomenal contractor to put them in once they are made. Is there a way you can make them & ship them to me at my expense?

  25. I have a house built in 1700 which already had windows replaced. I am looking for new windows to replace the ones I have that are more authentic to the house, like 9 over 9 or 9 over 6. Any suggestions? I want something that feels fairly authentic.

    1. David, there are a lot of window restoration companies out there that can build new windows for you that are exact replica’s of historic windows with counterweights and all. That way they are as authentic as possible! I would check in your local area and see who can do that for you.

  26. Hello,
    I need some expert advice. I am considering buying a home build in 1959 that has all the original metal crank out windows. There are several glass slats per windonw and they are not wide enough to crawl out of in case of fire. I love the windows and would love to keep the character of the house, but what is the plan for fire escape with these type of windows?

    1. Kim, it sounds like you have jalousie windows. There isn’t much you can do about opening these windows for egress means. Usually there should be an egress window in each bedroom that is openable.

      1. Wouldn’t it be possible to have authentic windows with cranks mounted WITHIN a locking door-like opening. Crank the window open, and open the door in a emergency. Install curtains for looks.

  27. Hello, I have an 1850s house. It’s a bit of an odd ball as it is a timberframe structure with a brick skin. The timbers on the main floor are about 8 x8 and the halved logs that form the floor joists in the basement are huge, the smallest being 16 inches wide. I have one original window left, it was a 2-over-2 design. The middle pieces of wood (is that a mullion/stanchion?) were removed at some point and single panes of glass were installed. I guess to match the newer ones which are 1-over-1. The tenons are still visible though. I suspect that the downstairs had the 2-over-2 windows and upstatirs had 6-over-6. Our garden shed has old 6-over-6 windows that are the exact size of the newer ones in our upstairs. I would eventually like to restore my one remaining window and have nine replicas built to replace the Pella ones I’ve got now. I would also need storm windows and screens. Would you have any contacts in Ontario/Quebec, Canada or in the Northeastern US? Or anywhere, if they are interested in lost distance customer relationships and offer shipping, of course. Thank you!

  28. I love this website and the idea of keeping the 1922 windows in the Craftsman i own is exciting. However, i have neither the time, inclination, or talent to do it “myself”. Do you know of anyone in the San Diego area who does this kind of thing? It’s impossible to call a window company…all they want to do is replace. I guess it just as to be someone who specifically works on old homes. Help! Carol

  29. What made you decide to fully replace your windows, Robert? If the wood rot is significant and would require lots of repair labor, I can understand your choice. For only 6 windows, you can do the work yourself of restoring the windows. Scott’s other blogs and videos are fantastic in showing you how to do it. The cost is likely about the same to restore as replace. Consider it a challenge and go for it!

  30. We are restoring a ca.1850 house. I would like to buy 3 sets of sashes (for 3 window openings). Each sash is 9 over 9, 28″ wide and 34 !/2 inches high. How would I locate such sashes? If they were made, how much would each cost (I would install and supply antique glass). Robert Bullock, Oak Hill,AL

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