Our new rooms have been coming along nicely. The only real eyesores left were our drafty, single pane 1964 windows that were begging to be retired. About a month ago (on December 13), we finally ordered two replacement windows for the new nursery and one for the new guest room, and they finally came in last Saturday. I debated the challenges and benefits of replacing the windows myself, but after a lot of researching how to replace windows and finding out how much it would cost for someone else to do it (2-3 times the cost of the window), I was ready to take on the task.
The first and most important step in ordering the windows was to take the proper measurements. Replacement windows use the existing, original window frame. The only things that get removed are the old window parts, which are different depending on the age and style of the old windows. When taking measurements you need to measure the length and width of the inside of the old frame in three spots. You then take the smallest measurement to order the replacement windows to make sure they will fit. The other measurement to check is to make sure the existing opening is square. For this you measure corner to corner in both directions. If the lengths are within a quarter inch you don’t have to worry. If they are off by more than that you’ll need to order the window a little bit smaller to ensure it will fit in the opening.

We were overjoyed when our new custom Andersen insert windows were delivered to our local Home Depot on schedule. We picked them up last Saturday morning, and I installed all three the same day with the help of my dad. They come well packaged along with directions and a few necessary items to complete the installation.

The first step was to gather all the tools needed to complete the installation. Items included a drill, caulk, caulk gun, stiff putty knife, square, tape measure, and nail gun, along with the included screws, shims, and foam insulation.

We then started by taking out the old windows and storm windows that attached from the outside. I would like to say that there was a precise technique for taking them out, but we really just pulled and pried until all the old parts were removed and laying in our driveway. Lucky for us, January was a surprisingly good time to do this job thanks to our unseasonably warm weather.

After the old windows were gone, the first step was to reinstall the old stool that we salvaged from the demolition a few weeks back. We stripped off all the old paint, filled holes and cracks with wood filler, and then sanded them all smooth. I used the finish nailer to secure it in place.

After dry-fitting the window in place to make sure it fit, it was time to actually make it a little more permanent. The first step was to run a bead of window/door caulk on the existing window sill in a large rectangle with about 2″ of spacing between the lines.

Here’s how it sat in the old window opening. There was only about 3/8″ of an inch spacing all the way around. I must have measured the openings about 6 times before ordering the replacement windows and once more after we ordered them, just to make sure they would work.

The distance from the stool to the top of the window needed to be set back evenly all the way up. For this we followed the directions and used a square to set the distance at the bottom of the stool and then slid it up the side checking and adjusting when necessary. When it was where we wanted it, we screwed it into place but didn’t tighten them all the way.

We then used the provided shims to slide between the new window and the old window frame where the screws attached. The old window frame wasn’t precisely square so we had to use different thicknesses of shims all around to make sure the window stayed level and square.

Then we tightened the screws all the way, fully securing the window in place.

We filled the gaps using some scrap pieces of insulation from when we re-insulated the walls and a putty knife.

Then with the provided foam strip, I insulated around the exterior of the new window. The windows came with strips that cover the insulation and are adhered with some caulking, to give the new windows a cleaner look, but with temperatures below freezing I thought it would be a good idea to wait until it warms up a little bit around here to attach those.

Now all that was left was to install our new window casing around the windows and installing new window stops to cover up the old window frame. Here’s a look at how the casing and the stops go together to cover up the window and old window frame.

Here is the finished product. Well, almost finished. We still need to fill all the nail holes, prime the old stool, and then give it all a final coat of paint.


After taking our time to make sure we were doing everything correctly on the first window, I was surprised at how easy it was to install them. The most important (and stressful) part was measuring and ordering the windows, since it’s hard to return custom built replacement windows. As for the windows we went with, we chose two very nice windows for the nursery. They are Andersen 400 Series Woodwright Tilt-Wash Double-Hung Insert Windows that we custom ordered from the Home Depot. We had a little bit of sticker shock after getting an estimate as they came in at around $450 each for similar sized windows. Thanks to that, we chose a cheaper window for the guest bedroom. Why? Well, we plan to remodel and add on to our house eventually and that window wouldn’t stay while the nursery windows would. So a vinyl window for half the price was all we felt we needed for the guest bedroom. It is still way nicer than the original window. Our three windows were kind of our Christmas present to ourselves because they were definitely a very large expense, but the difference it makes in the rooms is incredible. And we definitely want a warm and cozy nursery for our new addition.
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That’s great that you decided to install them by yourself. They look really nice, the room is really shaping up!