I found few windows in trash. They were relatively new (maybe 10-15 years old) wood framed windows, one layer double glazed and other with single glass - the gold standard for my home climate. I didn't know it yet when I pulled them out of the dumpster that I had actual use for them in the country house I am renovating. It turned out the set was exact fit for a spot where I wanted a bigger window :) Originally they probably were installed in pairs: two wide windows or two narrow ones. But for me the combintaion that I was able to pull out from the dumpster - one narrow, two wides, was perfect.

The issue with re-using this type of windows is that even though the openable frames stay intact, usually the outer frame gets completely destroyed while they are removed from the building. So I had to figure out how to build new structural frames around them.

After talking about the topic with a friend who is a carpenter it started to feel like it should be doable project by myself.

Here I describe the process, in which I made few mistakes but ended up with usable result. There are many different kinds of windows, so the details are not universal, but you might find some tips on how to approach the build if you happen to have some discarded windows you could put to use.

Supplies

Tools I used:

Miter saw (might get away without if you have circular saw)

Table saw (essential)

Circular saw (might get away without if you have miter saw)

Clamps (probably essential)

Drill, drill bits, screwdriver bits (essential)

Tape measure

Square

Sharp pencil

Handheld router (was essential for my project, you may have different situation)

Random orbital sander (might get away without)

Belt sander (was needed for weird operations, probably you don't need it)

Belt sander with a narrow belt (I'm not sure what it's called), a chisel should do the same job.

Tap cutter (need depends on type of hinges)

Step 1: Research

This exact type of windows are not too common in my country so far. We do use casement windows with two layers of opening frames but most of them have outer layer opening to the outside and inner layer to the inside, both layers have same dimensions. This set that I found has inner layer (with double glass and gasket) with larger dimensions and outer layer with smaller dimensions. I figured out the approximate mechanics that both of them have to open to the inside just by looking at the hinges. But it clarified few details when I saw a similar type of window on display in a construction materials store.

If you start a similar project with any type of windows it is a good idea to find a live example of the full system and take a good look at it. Also measure properties of the example you find. The gaps between moving parts are important - I didn't measure and regretted it.

Once I had a relatively good understanding what the outer frame is supposed to look like mechanically, it was time to think about materials.

Step 2: Materials

I believe mostly window frames are made of solid wood. But one has to be quite a pro woodworker to straighten such long pieces of wood. Wood tends to bend and twist and change with the changes in humidity. So using solid wood was absolutely intimidating suggestion.

Plywood for example is way more stable. But plywood is not good at heat insulation, which is a big thing in my home climate.

Thankfully there is a very nice intermediate option - glued laminated boards ("gluelam"). Because they consist of chunks of wood the heat insulation properties are same as solid wood. But the dimension and straightness stability is way better. Also it is pleasant material to be working with - sawdust is mostly wood, not glue or resin.

Laminated boards can easily be glued with wood glue. I bought a waterproof white wood glue (it's called "B3" here but I doubt it's internationally available, so just look for waterproof wood glue) - acts very similar to normal white wood glue ("PVA"), but after drying it doesn't dissolve in water (careful with your clothes!).

Laminated boards are available in my region in couple of thicknesses (18mm and 28mm) and few widths (200mm, 300, 400 etc). I chose to have the frame I was going to build to be 200mm wide so I didn't have to mess with long rip cuts. But with a good circular saw it is possible to make any width you need. Because the available thicknesses are quite thin I decided to glue several layers of gluelam together to obtain what I needed. In addition my window is very wide (over 2.5 meters) I had trouble finding so long gluelam. So layering two boards made it possible to combine the needed length from shorter boards (you will see afterwards how I did that).

I did have one side of the hinges attached to the windows and also the moving parts for the locking mechanisms but not the other side of hinges or the metal pieces with a slot where the latch is supposed to insert. I went to ask for the hinges in a lock store being prepared to pay quite a bit of money and buy not only missing halves but full sets. They didn't have exactly those hinges but guided me further. So I found a company that imports all kinds of locks, hinges etc. They mostly deal with bulk customers, but that means the prices were really low and they were willing to sell me only the parts that I needed, not the full sets. So tip: look for reseller who is less oriented to private customers (so harder to find), it can make big difference in the price.

The gasket was available in a construction materials store.

Also I am yet to paint the new frame and probably I will re-paint all of it. The glue laminated board will need a primer. And the paint has to be meant for using on windows.

Step 3: Planning, Drawing

I did some of my planning on paper but I reconstructed the process as way clearer Sketchup screenshots for this instructable.

If you doubt your 3D thinking abilites then it is even more highly recommended that you do make a model for example in Sketchup, or as top, side and front view on paper - you probably need one for with windows and another drawing of the frame only. (It doesn't have to be as fancy as mine, I made the windows look like windows just so that my screenshots would be easier to understand to others. On paper use colors.)

1. Measure the windows and figure out their placement in respect to each other. Top view and side view should suffice.

2. Take into account the extras like hinges and locks - how much room they need in which direction.

3. Compare the data you have so far with the dimensions of materials you are able to aquire. My window needed vertical posts between the windows. There I had to take into account the hinges of the inside windows and combine the thicknesses of available boards.

4. Decide the dimensions for parts that are not fully determined by constraints. Top, bottom and side pieces were like that - I could have made them thicker, consisting of 3 layers instead, but I decided 2 layers suffice.

Step 4: Cutting to Length

First step in the actual build was to cut the boards in length according to drawings.

Miter saw was used for this task.

Be precise!

Step 5: Cutting the Profiles

Cutting the profile was done on table saw.

To cut a simple square off from one corner of board (possibly it's called rabbet) you need to know it's two measurements. For me the two dimensions of the cut were 27mm and 10mm. Set the fence for one measurement and set blade height for the other measurement. Make a test cut. Measure the test result for both dimensions. Adjust if necessary.

Cut all the pieces in one direction.

Repeat the process for the other direction cuts by switching the depth dimension and fence distance.

Step 6: Glueing the Layers

I was lucky to be working in a shop that had a good number of clamps available. I wanted to get this step done quick - not to wait the glue dry in each piece separately. So I did the long pieces in one batch and short pieces in another batch. I put the glue on them as fast a possible, put the piece together, did next one, and once I had glue in all of the batch I clamped them in one stack.

Possible alternative to clamps: find an even surface and use weights to squeeze the pieces together. This is more viable with smaller pieces than very long ones.

For distributing the glue I poured it on the board and distributed with a piece of cardboard.

Step 7: Cutting Grooves

My design asked for grooves in the top and bottom piece where the ends of the vertical pieces go. These were cut after glueing the layers.

I tried to do the cuts with handheld circular saw and theoretically it should be doable. But my friend offered to get it done quicker with miter saw (it has a depth stop). I myself didn't feel like trying to slide the big piece by few millimeters at a time on the saw, but it was okay process for him. My task was to hold the long overhang horizontal to assure an even cut, a bubble level was handy for assuring that.

When you do this type of cuts first cut a test piece and check that the depth of cut is right.

If using handheld circular saw then clamp pieces of wood that would stop the saw from going over line. And pay attention to the fact that circular saw's base plate is different width on each side. I messed up the sides and got a cut in wrong place.

Make a cut right against both of the marking lines. Then make cuts inbetween so close to each other that that they touch. Clean up with chisel or a sander - I was able to use a belt sander with narrow belt, but it's not essential, sharp chisel does the job.

Step 8: Test Fitting Pieces

Now that I had all the components ready I started to assemble the frame. I was still in workshop and knew I had to take it apart for transportation, so I just put it together with screws, no glue.

It was needed to assemble the frame for measuring the hinges locations in most accurate way.

Step 9: Measuring and Installing Hinges

Now that the frame was standing up I started to fit windows one by one inside it to mark the locations for the hinges and install the hinges.

The inner windows I was able to keep in place with just clamps (first picture). Outer windows needed a scrap piece of wood in addition to support them (second picture).

For vertical placement of the outer windows that are supposed to have a gap I put some cards under them. Inner windows seemed to fit exactly, but if they wouldn't have then the simpler approach to them would have been to measure as they sit on the frame and then move the mark upward as much as seems neccessary.

I fixed a window in place with the clamps and used a square to mark the top, bottom and side of the half hinge that the window had. Then I measured from these marks the location for drilling the hole for the other half of hinge.

To be more precise I drilled with a small drill bit first and then the right size drill bit.

My hinges are basically a bolt. So I used a thread cutter. I can reinforce the wood inside the threaded hole with some wood glue but I'll do it during the final installation.

I messed up the location of one of the holes. To fix it, I drilled the hole to match a dowel I had and plugged it using glue. Cut and sanded to dowel down and made a new threaded hole as before.

Step 10: Measuring and Installing Locks

To make the recesses for the locks I disassembled the frame again and worked on separate pieces.

This is a step I messed up. I didn't do a drawing about those measurements but just went between the windows and the beams with the measuring tape. Therefore I didn't account for the radius of how the lock moves properly.

If you need to do something similar I recommend do a good drawing with measurements, maybe even 1:1 size. Then go back to your existing moving parts and re-check the drawing before cutting anything.

Because the metal piece I had to mount into recess has round ends it is logical to cut with handheld router. The bit diameter matched that of the metal piece. I clamped scrap pieces of wood on one side of the "line" I was going to cut and on both ends so that I could slide the router and have clear feedback where to go.

It seems to me the router bit is not meant to dive into wood on it's own, so I drilled a hole that would let the flat centre of the router bit to fall in the wood while the blades on the edges somewhat cut themselves in.

I don't have a picture of this but after this cut I had to do another deeper but smaller one behind the slot. I did that by eye because it will be hidden with the metal plate. Just be careful not to go as far as the screw holes in the plate.

Step 11: Some Adjustments

1. One thing I didn't quite figure out about the mechanics of those windows was this - is the gap around the outer window supposed to be that wide that the narrower window would fit through the frame while being in diagonal (seen from top). The issue was with the gaps that I left (which turned out to be too small, read til the last step) the wider windows do open, but the narrower didn't because the difference of it's width while being square to the frame and being in diagonally (one moment during the opening movement) is bigger than the same difference for the wider windows.

So I had to accommodate for that movement and carve a round recess into the frame. I did that by cutting a slot with circular saw that marked the deepest middle of the recess and marking the edges of recess. Then I used the round end of belt sander to carve an even radius.

2. Another thing that has to be done before painting is filling in some cracks that were left because the glueing wasn't ideal. I used sawdust mixed with the same wood glue as a filler.

Step 12: Assembly

I assembled the window near the location where it was going to be installed. I used some pieces of straight boards to assist with aligning the pieces vertically at similar height while glueing and screwing them.

I assembled the two centre beams first checking the squareness carefully.

To check that the frame is not twisted look at two of the edges (in this position top edges) from a really low angle. If one disappears behind the other all at once and not one end before the other then the frame is straight.

Time to install it into the wall.

Step 13: Installation to House

I don't have pictures of the actual installation but the method of installing a window goes like this:

The hole in the wall has to be 1-2 centimeters bigger than the frame on each side.

You make wedges - two for each spot that needs squeezing. That usually means each corner from two sides (for example top left corner from top and from left) and each end of any beams that run across the frame. The point is to wedge in the frame at those points where the wedge would not bend the frame but be facing an end of a sturdy beam.

You lift the window in place.

You put the pairs of wedges under the frame. One form inside, other from outside. Wedges facing each other like this and going one on top of the other make up a square in the middle. Sliding them further on top of each other makes the square higher.

You hit the wedges with a mallet in the bottom so that the frame would be plumb (bottom edge is horizontal) and at reasonable height compared to the hole in the wall.

Then you check the top of the frame not being tilted to inside or to outside. You fix this into position with wedges on the sides of top corners for example.

And when previous steps are done you add the rest of the wedges, slam them in well and that keeps the window steady.

Then you can put in few huge screws through the sides into the walls. You can put screws through bottom and top piece also but I didn't.

And then make sure once again all wedges are in well and saw off the ends of the wedges.

Now you can fill the gaps around the window with suitable insulating material.

I put the windows on hinges once the frame was installed into the wall because it would have been too heavy to lift otherwise.

Step 14: MISTAKES and Remarks

What I would do differently:

1. Spend more time on observing the example that I found in the store. Piece of important information that I didn't collect even though I had a chance: measurements - how much the outer frame is bigger than the windows inside it.

2. Same topic - leave sufficient gaps between the window and frame. Leave especially big gap if you are working in heated room. Wood shrinks remarkably when dry compared to outdoors humidity. After I had installed the frame and started to put the windows in I discovered that they really don't want to fit any more in the outdoors humidity. I had to sand the surfaces quite a bit to make them fit.

3. Always pay attention to which direction you are using handheld circular saw. Right measurement and marking can give you a cut in wrong place if you decide to turn the saw around.

4. Make drawings when measuring for moving parts. Don't just memorize distances, make a drawing with distances and re-check that. So holes, cuts etc don't end up in wrong places.

Other remarks:

The images show that the product has some plastic pieces that help the outer window to slide to right height when closed and not sag. And sadly I don't have a picture of that but on the outside there was a metal profile covering the gaps between the window and the frame - probably it's main purpose is to keep rainwater out. These two details I haven't added to my project. I didn't get the feeling that the hinges wouldn't be enough to keep outer window nice and square. And the metal profile I don't have so much need for because I installed my window in a location that has over a meter of overhang and no rain can ever fall on the window.

If you install a window in a usual wall that allows rain to fall on it, then consider two important topics:

- Use paint and primer that is meant for wet and harsh conditions and protect the wood well. Wooden windows need re-painting now and then to give them long lifetime.

- If you have similar type of windows add a moulding that covers the gaps around the opening outer windows to stop rain from seeping in - once water is in a narrow gap it can stay there for dangerously long time.

In conclusion I'm happy and proud that I managed to make things in dumpster to come back to life and be an important part of my future home :)