Making Your own Windows?

Hello fellow permies.

I was wondering if anyone here has experience in trying to save money by making their own windows. Windows can easily be one the single most expensive items when building a house, running several hundred dollars for a square foot or two.
Comparing this to the price of various see through materials, makes me wonder why not just make my own windows?

If anyone has any experience with this, I would love to hear it. I am particularly worried about fogging of internal panes.

Making windows sounds like a pain. You are probably better off simply reusing salvaged windows.

If you are looking for weather proofing and insulation, you can do an awful lot with external shutters and insulating internal blinds.

Window making is about keeping the outside, outside while also letting light into the inside. That means the frame needs to be not only secure but also weather proof, this can be done simply and or complexly.
Simply would be all the way from a frame placed in an opening then the "pane" put in place and sealed with either silicone or glazing compound (on both sides of the pane) to both hold the pane in place and prevent wind blown rains from penetrating the seal.
Complex usually involves either special planes or router bits to form the frame (rails, stiles and sills) and the individual pane holding framework (mutton bars).
These complex designs were developed for strength of the completed window (bigger and more glue surfaces in the case of the frame).

If you want to be able to build the window before setting it in place, the best method is the complex window frame with single pane per panel glass, it becomes simpler than the multi light, mutton bar type window build.
These are best made on a router table with a set of window router bits. You would also need a build table and some bar clamps to hold the frame square while the glue dries, you are also going to use mechanical fasteners (brads or nails) to hold the frame together.

this is a simple window design


this design can be turned into a double pane by using a thin strip between glass panes. To keep the interior pane from sweating you have to drill at least one small hole at the bottom of the outer pane so the condensation has a way to get out.

You really, REALLY want double glazed windows.  Making these yourself might be possible, but I suspect that it would cost MUCH more than simply buying them.

You want the space between the panes filled with a dry gas (frequently they use argon) or you will end up with condensation between the panes, where you can't clean it.

If buying new windows is too expensive, look for good used windows.  Possibly from a hotel or other business that is renovating, etc.

Do not use single pane windows.  You'll lose so much heat through them that buying brand new double pane window will seem cheap after a couple years.

Don't waste your money on triple glazed windows unless you can get them cheap.  They are slightly more efficient than double glazed, but not enough to make them worth the (typically) higher costs.

Have you seen that technique where people hang water+bleach-filled bottles in their shed ceiling to allow light to travel through? I wonder if you could use something like that to offset the need for large windows?

It can be done, but there are a few considerations that may not be apparent. As mentioned by Peter above, they use a dry, dense gas between panes to reduce convection between inside and outside panes which reduces heat transfer. Also, I believe many new windows over the past several years or more have special coatings on them; UV blockers to reduce sun damage to your house interior, and nearly transparent reflective coatings to bounce some radiant heat back where it came from (keep outside heat outside, keep inside heat inside). It might be worthwhile to see what manufacturers are providing and what purpose they serve so you can determine for yourself what your needs are and how to mitigate any potential problems.

If you live in a tornado or hurricane zone, you are usually required to have impact resistant windows or shutters. This may not be mandatory on a wheeled tiny house, but if it moves down the road that seems to me to be all the more reason to protect your windows from being breached by debris. Shutters that can be worked from inside can help with heat transfer, as well as absorb physical damage, and still be safe for exiting in case of an emergency.

Used windows or ones that are discounted because they are the wrong size are one option, but it can take longer to find exactly what you want than the time it would take to build the rest of the house. You would literally be building the house around the openings. If you do go the DIY route, it would probably be very advantageous to try to make as many of the windows as possible a standard size. If you ever have an accident or vandalism, you don't want to be up all night trying to build a new window or living with a tarp strapped over a broken window for any length of time. Being able to buy one when you need it, or have several the same size and building one extra would give some insurance that you can fix a broken window in a timely fashion.

Thanks Bryant RedHawk.
But, question, is that window just copying windows that slide open, or would it include some sort of track? That was one feature I was wondering about the most. How important is it that I have opening windows?

I had heard about that small hole trick.

@Matt Coston: I had not even heard of those. They look really neat.

For fixed windows it's not difficult and definitely doable. You don't need to make the glass yourself, custom double pane can be had from glass shops. I could get a 24ish by 40ish double pane for 85$ CAD(can't remember the exact dimensions), that was 10 years ago though.

If you want windows that can be opened that's another story. The five I made are single pane because the windows were for a shop and I salvaged glass from trash on my land. With single panes in winter you'll feel as if you were sleeping outside. Condensation on the inside will rot your sills. You need well seasoned wood because warpage means stuck windows at best and cracked glass at worst. In humid summer windows are sometimes hard to open, in dry winter they get loose and let air in. You need good tools and good skills to minimize air leaks. And in my case it took lots of time and lots of patience. That was not an easy project. I don't think I'd do my own for a house.

After 10 years they still look good. That was this evening, sorry about the blurry picture it was getting dark.

Jon Wisnoski wrote:Thanks Bryant RedHawk.
But, question, is that window just copying windows that slide open, or would it include some sort of track? That was one feature I was wondering about the most. How important is it that I have opening windows?

I use either a track system (easy peasy; just measure, set and screw) or for restoration work the track is part of the frame (either routed in or tacked on strips, depends on the original workmanship of the house).

Do you have a Habitat Restore near you?  They sell donated building materials that won't work for Habitat for Humanity house builds.  They often have affordable new or used windows.  Otherwise Craigslist always has them.  I'd really really really really consider just buying decent double pane windows if I was in your shoes.  

Hi John and permy people,

I understand what you mean about the cost of windows.  It is certainly possible to make your own and there are definitely alternatives.  One of the best sources I know of for ways to fiddle with getting sun light and energy into your home is:

https://www.builditsolar.com/

If I were going to make some sort of DIY window, this is where I would start.

There's more to windows than you might think.  Even the old-school kind, are surprisingly complicated little buggers:



If you do decide to make your own traditional windows, there are some key principals to keep in mind.  Here are the ways windows transfer energy:



There is a surprising amount of building science packed into a window.  Modern windows have to do a lot of things and some of those things are in direct conflict with each other.  Below is a list of what windows should / could do and the components that accomplish those tasks:

Integrate into the building envelope - Nail flange

Keep weather out - The whole shebang pretty much

Keep indoor air in - Welded or sealed window construction techniques

Open and close - Springs, slides, counter-weights, other hardware

Lock securely - Lock hardware

Provide water an exit path - Weeps

Prevent water from getting caught in the window or wall assembly - Weeps and welded or sealed window construction techniques

Prevent water from entering the building during a differential pressure event (severe weather) - End dams

Resist the flow of heat (R-value) - Thermal Breaks, insulated panes, internal insulation

Reduce heat gains - Low-E coatings (this is situational)

Reduce UVA - UV coating

Block UVB - Any glass will do this

If you compare this list to the double hung window diagram above, you might notice that most of the things I just listed are not accounted for in the "Anatomy of a Double-Hung Window."  They represent decades of design and performance improvements that are the result of general advances in technology like material science and our ability to measure the flow of energy.  Take a look at a more modern cross section:



There are trade-offs to be sure.  A modern window has a MUCH higher embodied energy than something you might make yourself (the energy to fabricate, package, store, sell, transport, etc.), but if you look at the life cycle of a building, that modern window will generally save a LOT more energy that it took to make.  The more energy you use to heat and cool your home, the more money and carbon your efficient windows save you.



I'm not sure you could get results like the passive home depicted above without modern windows.  My advice is look at your construction budget and your operating / monthly budget and make the best decision you can.  Remember, it doesn't have to be an all or nothing decision.  Maybe you could make one window on your own and see how it goes or buy a new or used window every few months.

I hope this helps . . . please let me know if there is anything I can clarify for you.

P.S. https://CruxHomes.com

When I worked for the railroad at an engine house, cracked windows had to be replaced by Federal Railroad Administration rules, but they were never really bad because locomotive windows are bullet proof. (Sadly that is needed because several times while operating locomotive I have experienced being shot at.) That means just one layer is cracked, but still they work well. I just made frames for them and used them in my barn.

I recognize that not everyone has access to bullet proof windows, but being inventive, people can find glass and frame out a window.