Windows are the eyes of a house—the most important character-defining feature creating the greatest visual impact on the overall appearance of a house.
So should you replace your old wood windows?
Should you consider restoring old windows?
And if you require window replacements, do you know what to shop for based on the design and style of your house?
The public has been brain-washed by marketers.
Even an eight year old knows you need to replace your old wood windows to save energy and lower your heating bill.
As eyes to a human, Windows are the most important feature on a building.
What else can you expect with all the advertisements and promotions manipulating the public?
But you have to remember, this is big business and big sales commissions are paid to highly trained people to convince you that you need window replacements. Their livelihoods depend on these sales.
Additionally, with the trend of saving energy at home and making everything “green”, misinformation from the current sustainability movement has embedded in our minds that all old windows are NOT efficient and NOT green.
Financial incentives such as tax credits for home efficiency improvements, have escalated the situation to a frightening degree, making old windows the most vulnerable element of a building.
The result? You spend money that will never be regained – a very bad investment. Additionally, the character of your house is destroyed forever.
Note: The term historic window may be used to represent an original window – one that is wood and original to the house. It does not have to be 100 years old or be ornate to be valued and worth preserving.
Circa 1750 window has character.
1950’s window also has character.
Windows Replacements are NOT Green
and will NOT Lower Your Heating Bills as You Think
With global warming imminent, you cannot escape the talk of this and LEED (Leadership in Energy and Environmental Design). Replacement manufacturers anxiously take advantage of this opportunity as a salesman selling snake oil during times of sickness.
Window manufacturers easily convince homeowners of great energy savings associated with their product. A replacement window seems to be the logical “green” choice.
While this claim may correspond to newly-constructed, LEED-certified buildings, the argument that window replacements are “greener” than restoring old windows is FALSE.
A common and often exaggerated reason for window replacements is that new windows will significantly reduce heating costs. This is wrong!
Studies indicate that in most cases, approximately 10% of the a buildings heating loss is through windows.
The remaining 90% is lost through gaps in roofs, walls, floors, and chimneys, with roofs being the greatest culprit. These other areas of heat loss can be resolved at a much lower cost and result in much more savings on your heating bill than replacing windows.
Following this model, reducing the heat loss through windows by 50% will only result in a 5% decrease in the overall heat loss in the building and your heating bill.
Pay close attention to ads claiming, a 50% reduction in your heating bill. It is all a tactic to get you excited and interested to save heating expenses. It is NOT a 50% savings of your heating bill.
IT IS a 50% savings of the 10% heat loss through all of your windows, which will save you only 5% off your heating bill if you’re lucky.
Even with this in mind, keeping the heat in and the cold out are still prime wintertime goals. Both goals can be met with your existing original old wood windows! Keeping the heat in, means insulation measured in R-value (measurement of a materials resistance to heat flow).
Old windows coupled with a storm window with LOW E glass coating will give you a higher R-value than a double-glazed replacement window.
This is because there is more air space between the storm window and the inside window than between the two tightly squeezed panes (double pane) of glass in a replacement thermo-pane window.
Believe it or not, AIR is one of the best insulators.
Since molecules are so far apart in air, heat cannot be transferred.
Therefore, the three inches of air space you have between the two pieces of glass performs as a very good insulator.
Let’s look at this in another way.
- One measure of heat transfer is the U-value – the number of BTU’s per hour transferred through a square foot of material. When comparing thermal performance, the LOWER the U-value the BETTER the performance (opposite of R-value).
- According to ASHRAE (American Society of Heating, Refrigeration and Air-conditioning Engineers), the U-value for single glazed old wood windows ranges from 0.80 to 0.99. The addition of a storm window proudly reduces these figures to a range of 0.44 to 0.49.
- A double-glazed metal window has a U-value of about 0.60 and a double-glazed wood window ranges from 0.51 to 0.55.
Therefore, if you do not presently have storm windows, install them instead of window replacements. You will spend much less money, receive much more insulation, and not add to the landfills.
This U-value CAN be lowered further, but at this point we are slicing peas. With windows accounting for only 10% of heat loss, you really do not need to look further. However, if you do, with a Low-E-Coating Storm Window you can lower the U-value to a .32 level.
Adding storm windows is a less costly investment and, more importantly, you save your original old wood windows (and the beauty of your house).
You will not be responsible for adding to the landfill and destroying our planet.
You can also add INTERIOR storms for even more insulation.
Historic windows end up in the landfill. Replacement windows will too in 15-20 years. Photo by Mexi Lane
You Must be an Educated Consumer
Keep in mind your source of information. Does your information come from someone with a financial benefit? Are the statistics weighted? Are they geared for new construction?
Don’t be blinded by the lure of tax credits when you can save ten times more money making an educated decision.
As with nutrition labels, there is some misrepresentation of U-value measurements.
See the following link where the author advises window shoppers to make an informed decision:
Traditional Building Magazine – Do You Replace or Restore Historic Windows
Old Wood Windows vs Window Replacements Energy Analysis
This is important folks. Here are three insightful documents that discuss the cost of window replacements versus historic wooden windows.
Saving Windows, Saving Money: Evaluating the Energy Performance of Window Retrofit and Replacement by The National Trust for Historic Preservation
This report analyzes do-it-yourself solutions such as window films and weather stripping to replacing older windows with new ones. This study builds on previous research and examines window options comparing the relative energy, carbon, and cost savings in various climate regions.
This link is a summary so scroll down and click on the links for an extremely through report.
A Comparative Study of the Cumulative Energy Use of Historical vs Contemporary Windows by Frank Shirley Architects.
This study compares the life-style costs of two residential window systems in a pre-1940 house in Boston, Mass. One is an original double-hung window with a triple track storm window. The other is a new, vinyl double-hung replacement window.
Studies and Experts Prove Window Saving is Better
If you haven’t read enough and still don’t believe the Replacement Window Myth, here are some more links to random energy savings studies at Historic Home Works.
The Science of Drafts and Where They Come From
What about drafts? You can feel the same draft with brand-new, “top of the line” windows, as well as with your old windows. The culprit? Convection. Glass is a great conductor. The warm air in your house contacts a cold window glass, where it cools and then draws more warm air to it. This continues on and on until convection currents are created throughout the room and perhaps through the entire house.
This draft feeling is created only because the product GLASS is used in a window. If you really want to prevent drafts, you can use wood instead, however you will not be able to see outside.
Use of interior shutters, shades, or curtains can solve the draft problem by blocking off the glass from the warmed room air. An additional layer of glass (storm window) which creates an air space between the two glasses will help; however, you are still using glass, and heat will still be drawn to it, although not as much.
Energy Saving Information Specific to the Older Home
The National Park Service – Department of Interior, provides a Technical Preservation Service. Highly qualified experts working under contract with the federal government have assembled more than 40 booklets designed to help owners and developers of historic buildings recognize and resolve common preservation and repair problems.
These links from the National Parks Service can help you understand how to improve energy efficiency:
- Conserving Energy in Historic Buildings – Preservation Brief #3
- The Repair of Historic Wooden Windows – Preservation Brief #9
The National Trust for Historic Preservation is a great resource for any information you would need for an older home. They also have a good section on weatherization. However their webmasters constantly move around information which results in bad links for you the reader. This is bad business. OHG and other sites would like to direct you to these links to help you but NTHP is not a team player. I have therefore removed all their links to specific articles and will supply only the link to their main page. Click to go to www.preservationnation.org
Window Replacements Are NOT Maintenance Free
A big myth is that replacement windows will eliminate maintenance. In a way this is true because they are disposable.
You install them; 10-20 years later, you throw them out and, again, buy new windows. Even so, the public has been sold on the myth of no maintenance, but there will ALWAYS be maintenance.
- For appearance sake alone, you certainly will be painting those windows even if they are vinyl. They too will fade over time, just as aluminum sided homes, which were once touted as “maintenance-free” are being painted.
- When wood is continually maintained, its life expectancy can be about 200 years to indefinite. On the other hand, according to studies, vinyl has a life expectancy of only about 20 years. The plasticizers in vinyl will evaporate over time, making the vinyl brittle and subject to cracking. And what cost are you imposing on future owners or your poor unsuspecting children when your venture doesn’t last? Go with time-tested materials: paint on wood.
- How are you going to replace a double-glazed pane of glass when it breaks? Manufacturers frequently modify their product line and technology quickly changes. You may, therefore, need to replace the entire sash and frame. Many other components of replacement windows deteriorate relatively quickly.
- The seal around double glazing can fail within 10 years, resulting in condensation between the panes of glass. This will require replacement, too – not repair. Many of the plastic and neoprene seals, which hold the glass in place in vinyl and aluminum and new wood windows, also degrade in ultraviolet light.
- “Insulated glass typically lasts from 10 to 25 years , with windows facing south often lasting less than 12 years”. Try to imagine locating a replacement vinyl gasket 10 years from now, or the problem of replacing a bent aluminum channel. With your original window you can always get parts at a local hardware store.
What are My Options to Save Energy?
- Install an Exterior Storm Window with low-e glass.
- Install an Interior Storm Window .
- Install the newly invented Pilkington Insulated Glass.
What is this Newly Invented Pilkington Insulated Glass?
Pilkington insulated glass is new for 2018. This glass will not only save heat and cooling costs but save the homeowner thousands of dollars for replacement windows. This is not good for the replacement window business. They will now have to apply more pressure on the homeowner.
Basically this insulated glass is the same thermopane glass used in replacement windows but reduced in thickness to that of a single pane piece of glass. It has improved insulation properties and can be inserted into your original historic window.
The problem I see is that your historic wavy glass will be replaced. I’m sure in time that there will be an option to have wavy glass.
Read more about Pilkington Insulated glass .
What About the Appearance of My Windows?
Repair or Replace – The Visual Impact
Appearance is Important. The National Trust for Historic Preservation addresses the following questions with great pictures in living color to really show comparisons.
- Should I repair my old windows?
- When are Window Replacements Necessary?
- Do the Benefits Outweigh the Costs?
- What Not to Do When Replacing My Windows?
- Do Window Details Matter?
Additional Sources of Information to Help the Homeowner
Should Your Old Windows be Saved?
This article focuses on common problems with old windows and what you can do. Options of replacing old windows are weighed against the cost, complexity, efficiency, and preservation of historic character with a problem-and-solution approach. A Visual Guide to Historic vs Replacement Windows.
Replacement windows are not what you are led to think they are.
Vacuum Insulated Glass, Innovation for Historic Restoration
Brand new glass technology allows historic window sash to be retrofitted with insulated glass and still look historic. (except for the lack of wavyness)
A window tip sheet from The National Trust for Preservation
What does old versus new wood mean and how does it effect wood products today?
Now that you understand how to avoid being influenced by the false claims of window replacement marketing, it is very important to understand how windows effect the appearance of your house.
I would like to get replacement windows. Can you tell me which is better, aluminum or fiberglass a couple will have window AC units in them . Also should I get double pane or triple pane insulated windows. I live in Chicago and the winters get cold here. And can you refer me to a contractor in the 60630 area code, or which is the best Company goal .
Thank You
Ronald Prohaska, Sr.
We don’t endorse replacement window here. Didn’t you understand the information on this website?
This is all great info. I’d really like to save my 100 year old windows. They need some restoration, but I can make that happen. What I am finding it difficult to locate is appropriate storm windows. Do you have information on where to buy high quality storm windows, either wood or aluminum? I have tried in a few places, but everyone tells me they can’t make them for me, that I should just get new windows.
Storm windows are definitely the answer and they will also be part of the Energy Star Rebate program.
http://www.oldhouseguy.com/wood-storm-windows/
https://www.oldhouseguy.com/storm-windows/
I live in a 2900 sq ft 1915 cratfsman style home in small town Kansas. I have 50 windows all original. Every spring a couple of door to door window salesman come to my door seeing $$$$. I love schooling them when I explain that my windows are over 100 years old, and in another 100 years they will still be here, vinyl windows won’t.
I love it!
Great writeup. The USA could really use a preservation-minded billionaire to throw some money into informing people that the replacement window industry is a complete scam and to save their old windows.
So true. Another way would be for storm window manufacturers to advertise their benefits on TV and radio.
Good Afternoon * We used wood windows when we built our guest house in Garland, TX.
These are not antique wood but multi-pane that match our 1937 Colonial Revival house.
The city wants us to buy replacement windows. We want to use low E storm windows over our wood windows – we do NOT want replacement windows. Do you have any reference material I can provide to the city ?
Thanks for all your info and work to preserve old houses.
Sincerely,
Jackie Mumaw
Garland, Texas
That’s terrible! Don’t let them bully you to ruining your house. Everything I have about saving windows along with information against replacement windows is on the windows page of my website. Feel free to use this information in any way that it can help you. All the studies state that the appearance of original wood windows must be maintained. Good luck! Ken
your web site has influenced me to reconsider buying replacement windows. I have been considering new windows for my home. The original windows are Pella casement on a home built in 1975. I have significant rot in the sill in one window, along with multiple malfunctioning crank operators and sticking windows. concern over this led to recent visits with various window replacement companies, because that seemed like the only option. One salesperson actually brought up the old growth vs new growth wood concept you speak of, and it made me think, because something was not feeling right. I don’t yhink 1975 qualifies as old growth, but My original wood windows look better than any of these new windows ranging from $17k to $32k. (10 openings-20 panes) although interestingly
, it wasn’t the money that was bothering me, I realized it was losing the original integrity of my well built house. One thing led to another , beginning with searching for replacement Pella components and eventually led to you. thank You.
Thank you! True new wood windows (1960’s and newer) are not from old growth wood. Still however they are wood and have the correct design. It is still probably less expensive to restore them instead of replacing them. Don’t forget to add that storm window with low-e glass.
I was convinced to replace my 100-year-old windows for “energy-efficient” vinyl windows. As a first-time homeowner AND first-timer living in a historic home, I was eager to remedy the draft in my home and make it more comfortable and was told by several people and salesmen that replacing the windows was definitely the way to go. My home is still drafty, my bill isn’t much different than before, and they threw away my original windows without my permission. To make matters worse, I learned after the fact (by way of a violation notice) that we’re not even supposed to replace any of the windows on our homes in this neighborhood without approval (luckily I still have 4 of the original windows on the front-facing side). I am living with regret in a home that I worked hard to obtain, and I hate that I’ve compromised the integrity of the home, even though I was literally freezing in here. Now I’m faced with what to do next at this point. Should I replace the vinyl windows with a wood replacement? Are there places to go where I could purchase old windows to put back in? Or do I just chalk this up as a learning experience and move on? 🙁
It’s really sad that the in 100 years your house survived, you are the person to destroy your house. Once original windows are gone the house is considered damaged. Imagine what future owners will say looking back. An old house is not for everybody. I understand that you are new to historic houses but didn’t you even think about researching what it takes to live in such a house? There are many resources online not to mention checking with your historical society or local preservation commission. Your windows may be drafty but didn’t you ever hear of storm windows? When the salesperson told you that the replacements will be white plastic, didn’t that sound odd for a historic house? White plastic windows will look better if you have formica furniture. Did you not ever make a purchase where you worked with a salesperson that gets a commission? Do you actually think they would say not to purchase their product so they can not get a commission? I’m sure you have seen historic houses before and also remuddled houses. If you purchased this house because you like it, didn’t it ever cross your mind to notice why you like this house with the original windows compared to one that was compromised? With a new or old house or anything you purchase did you not hear “Let the Buyer Beware”? You spent a ton of money on something very bad. Besides my website many others state that new windows are a foolish investment.
You will need to replace the windows with exact replacements. They will need to be custom made with reproduction historic glass. They still will never be as good as the originals made with heart-grown wood you cannot get anymore. They will not last 100-200 or more years as the originals would. You can try Heirloom Windows – they make a reproduction window. I then recommend selling the house before you do more harm. This is very sad.
I’m sorry to be harsh but when making such a huge purchase on a house, one would normally do some research and know that old houses can be drafty and things like insulating the walls can lead to the demise of an old house.
Old house owners are merely stewards, taking care of a piece of history for the next person.
a similar situation to yours:
http://www.scoutingny.com/the-saddest-house-in-new-york-city/
https://www.oldhouseguy.com/cottage-additions/
There’s one form of evidence of the effectiveness of the vinyl window industry advertising I see quite often. A house will be in bad need of a new roof and/or other repairs. But, by golly it’ll have every window replaced with a bright white vinyl one. To have replaced all those windows couldn’t have been cheap. I’d be inclined to address other issues first, like a water tight roof and to make sure the foundation is secure. But, unfortunately the lure of supposedly no maintenance, heating bill savings and the Energy Star discount is very strong. Also, I don’t imagine roofing contractors are as aggressive as vinyl window salesmen in showing up at someone’s house to advise them that they should really think about having their roof re-shingled. So, a homeowner may think about replacing windows first before everything else.
So true – window sales people are trained to be aggressive and probably get a huge commission.
I am building a small addition to a Houston bungalow to be attached to a new garage with pool house on the front of the garage, alley entrance behind. I am keeping the original windows, double hung, 20 over 1 and quite tall, ceiling height is 11′, in the house and having them restored. Almost all are working, very little cracked glass, replacing all sash cords, and making them secure and weather proofing. All have their original screens, no storms. If after a year or two I am uncomfortable I will have storms made. It’s a one story house. I bought the house because of the windows, they are staying. That said I need new window for the newer part of the house. There will be windows across the addition connecting to the garage, and also across the front of the pool house. I am trying to find something available to put in the newer parts that complements what is there currently. Both the addition and pool house sit at the back and to the side of the original and will have landscaping to soften the view so any discrepancies from the original windows will be lessened. The original windows closest to view from the street are a mix of 2″4″ to 2’8″, all vary a bit in inches. So the overall effect is 2’8″ which I am guessing would be the best size to purchase in new windows to complement. I have searched area historical salvage and cannot find anything similar in look and size and quantity so am buying new. I did research custom and for the number of windows, 23, fortunately not all front facing, it is cost prohibitive so I will do the very best I can do.
I am thinking since new 20 over 1 is not available, that I should do 1 over 1 or 2 over 1. The house is not a craftsman on the exterior, with doric columns off center front double(skinny) doors, the interior suggest more Georgian, tall ceilings with large baseboards and crown, it was a surprise walking in. It was built by a retiring cotton plantation owner. Any suggestions on what to look at brand wise, design wise? Again coastal Houston weather is a consideration. thanks for the help.
Wow – this is really hard to follow. I never heard of a 20 over 1 window. Please email me with good quality photos.
I love my 100 yo windows that are big enough through which to carry my upright piano! The weight cords are broken, and someone puttied over the pulleys. Of course, this makes the window almost impossible to use. My question is insulation; those pulley pockets are 8 inches of empty wall space. Doesn’t that contribute to the drafty old window complaint? The appearance isn’t changed if I stuff insulation inside, and I can enjoy the view, while reminding myself that windows of similar size are stationary on modern homes. Would I notice a decrease in drafts by insulating, or should I follow my heart, and repair the weights?
you should contact the Window Preservation Alliance.
Hello,
Needing some help finding someone to restore my 120 year old windows in Kirklin, IN. Can you assist with this? Also, how might I go about insulating the weight pockets? I am also trying to find some nice storms.
Thank you,
Colleen
All the information is here. Please read.
I have been restoring the wood windows in my 74 year old house. On an addition done in the 70’s a wood window was installed and does not have any weights or springs (balances?) for the window to stay open. There are 3 wood windows with metal glides on the side (not sure what they are called). I did purchase Pullman Sash balances from “This old house” to install in the one wood window for when I get around to refinishing it. Every time I think about working on it I think I would be better off replacing these 4 windows with wood clad windows. Then my dilemma becomes how do I make it match the rest of the house? I finally decided I would look into replacing all the windows in my house (16) and I have talked with several people, but can’t seem to find peace on making a decision. I got online tonight and found this site. I would prefer to keep my wood windows. So, what are your recommendations for the 4 windows as described above, which are not the same as the rest of the house? The other question I have is about the window sills. On the windows I have restored the paint is peeling on the sills on the outside. How do I prevent the window sills from peeling? A rep at Benjamin Moore said Polyurethane should be put on??? I don’t want to have to repaint them every couple of years…or is this what is needed? Any advice is appreciated. Also, you mentioned how so many women are refinishing wood windows. Can you recommend a site where I can get information on window restoration? I have been doing this all based on common sense. Thank you.
Hi Diane – are the 4 windows not original to the house? Are they the windows from the 1970’s? Is this why they do not match the windows on the rest of the house? Sorry – Not following you.
Your window sill should not have a peeling problem. There may not be enough of a slope to the sill or it was not primed or the wood was wet when painted. So many reasons. I never heard about using a Polyurethane coating. True window sills are the most vulnerable area since they are almost flat. That along with a hand rail. I would apply a quick coat of paint every few years. A cheap easy fix for a great lasting look.
We now own my grandparents’ house, built by my grandfather and his brothers in 1950. The house generally hasn’t had any major renovations since then, though my grandparents took decent care of it. I have always liked the original double-hung (and a few casement) Andersen windows. They have been protected by (ugly) storm windows for most of their lives but they do have a fair share of issues. Some don’t stay up all the way, there are areas where there have been repairs and many coats of paint (much of it with lead). We also definitely need new storm windows.
I got a quote to restore what we have and it’s a few thousand apiece including new storm windows. We’re potentially willing to do it, but we want to make sure that these are actually worth saving. I can’t find much on Andersen windows of this vintage, but I’ve read that right around 1950 when they started being more mass-produced and they stopped using old-growth wood. Are these windows worth investing in and keeping?
The other wrinkle is there is probably going to be some mixing. We have one of these double-hung windows in the shower, so I don’t see any way around replacing it with something fiberglass perhaps. Also we hope to add an addition in a few years. Obviously, the addition will need windows. What is the best way, in your opinion, to handle this? Are there some types of modern windows that can look OK alongside vintage windows? One thought we had was to keep only the windows facing the street original but put new windows in back, so that we could take original windows from the back and put them on the front of the new addition. Is this type of transplant realistic? Or maybe you know some other strategies for mixing old with new in a way that looks like it was meant to be?
Old growth wood is wonderful but if you have a house say from 2000 that has wood windows, I say they are still worth restoring because replacing them with new wood windows is expensive. Now if they are 1 over 1 you won’t see the difference as with 6 over 6. Best to restore the originals and play it safe. With an addition you DO want to see that there is an addition and not create a false representation of history. The windows and styling can be different but compatible. Just do NOT get those tacky plastic grids.
OK, so let’s say I get them all restored, which is totally doable.
I’ve read your site extensively now and I’ve discovered that my outside casings are a mere 2″ wide! You say some things on these pages about how the architect knew what he was doing and so on. But bear in mind this was just some of my family members who did likely follow some standard practices and I do think they did decent work, but I would be wary of attributing a higher design philosophy to them. I have a background in human perception and I know it is a science that some designs look better than others. I worry that the “architects” might not have followed best practices in this regard.
Have you seen such small casings in houses from this time period (shortly after WW2 in New England)? I don’t think they look bad, per se, but after reading your pages I wonder if they could look better with slight improvements?
Hi – yes I have seen narrow casings for after WWII and even much earlier which was far from the normal way. The wider would look much better but I would keep what you have that is original. Things may have not been designed the best way and yes you can improve it. The way I look at it is that I would keep what was original even with a not so great design. You can probably argue it out both ways.
I apologize for not being clear in my previous post and for the very late response. I believe the polyurethane information I received was for door thresholds, not windows. I have learned quite a bit since July when I finally decided to restore the windows, including replacing the rotted window sills with Port Orford cedar. All the sills have a 7 -8 degree slope. I think previous owners did not care for the windows, which contributed to the rotting. I think the paint was coming off on the window sills I had previously restored because I did not use quality paint and primer, I did not properly fill cracks, and they are on the south side of the house. I stripped them down again, filled the cracks with wood epoxy, used a quality oil based primer, and Benjamin Moore Aura paint. That should do the trick. I am not sure if the windows on the addition are from the 70’s. I assume so since the addition was done sometime in the 70’s. They have metal sash balances and I was not sure if I could restore them because they are different from the rest of the house and I was unfamiliar with them. I was able to restore them, and they work great. I purchased storm windows. All the windows work and look beautiful. They only problem is trying to figure out where air is leaking as I have moisture collect on the storm windows with cold weather. As a side note, being the reason I decided to finish restoring all the windows properly, I had vinyl siding on my house put up by a previous owner. I discovered cedar shingle siding was underneath. My neighbor offered to help me remove the vinyl siding and reside the addition with cedar shingles to match the original part of the house. Now the outside of my house is completely restored to it’s original 1946 state. So worth the money and 4 months of very hard labor!
We are in the process of building a timber frame home. We found and purchased 1969 Pella windows with the interior storm windows and screen included..perfect condition. Our dilemma.. no information of U factor located on windows. We fear the building inspector will fail our dreams to use these beautiful windows (u factor of 30 is required in our county) any idea how we could get this documentation or knowledge?
Sincerely
Jonni
Don’t know. You can add a storm window if needed.
I can’t thank you enough for all this valuable information!