I'm just a housewife, not an expert, but here is how I have patched my stucco. Use regular wood exterior sheeting to fill the hole. Attach two layers of 30# roofing felt. The one closest to the wood helps keep the wood dry, the second layer needs to be wetted down when you apply the stucco and is crucial in getting the stucco to cure properly. Over the felt attach galvanized self-furringt lath with fasteners no more than 12" on center. I'm assuming you have the same stucco recipe as mine. For the scratch coat use 1 part portland cement, 1 part hydrated lime and 2.5 to 4 parts sand. For the next, brown coat use 1 part portland, 1 part lime and 3.5 to 5 parts sand. For the finish coat use 1 part portland, 1 part lime to 1.5 to 3 parts sand. The finish coat is pretty thin and more just to texture the finish to match the rest of you stucco. I use a wallpaper brush to scratch up the first and second coats. Make sure you really wet down the surface before you apply each stucco layer and to keep it misted so it doesn't dry out too fast. If you are trying to match the exterior texture I would make a practice board and try some different techniques. Some old stucco's have pebbles in them but I could never find any small enough to match mine (mine has more of a mica in it). Those were thrown onto the finish coat and pressed in with a broom. When we put on our dormer I just textured with a sponge and broom since it was pretty far away from the older stucco. When we moved the four windows for the kitchen remodel it was on a newer (60 year old) addition and there were no pepples added. I used an sponge to texture the top coat and then loaded up a wisk broom with stucco and slung it at the wall for texture. It worked well. If your stucco is unpainted you can try to match the color by adding pigment but you need to do a tester board for this and to allow up to 60 days for the color to cure. If you are matching a painted stucco then prime the new stucco twice (after curing) and then paint the patch. Then paint the whole wall of the patch if possible. New stucco absorbs a lot of paint and if you don't get a few layers on the stucco will look different that the rest of the wall. DO NOT use house wrap (or stucco wrap) under the stucco. It will not dry out properly and it will lead to problems down the road. The Portland Cement Association has some stucco tips on their website and you should read those. I would also recommend that you verify what kind of stucco you currently have. You will have a failure in your patch if the composition is different than the existing siding. The site listed below should help with that. Here is a link that might be useful: how to figure out your stucco base.

Yes, Yes and No.

Thanks for the reply. I was thinking the nicest look would be to remove them and have the contractor repair the holes with stucco during the color coat process, and then finish the front of the home with the foam trim detail, but I do not want to create a future water problem. I'm wondering if the second stucco contractor suggested leaving the wood because of that? If I'm not removing the wood, then I wonder whether to give up the color coat and simply paint? It's so much cheaper. Also, FYI, some of the home's windows are trimmed with wood and some are not, so it is not consistent (there was a kitchen addition, and the stucco comes to the sill there.) I want to do what will give my home the best appeal and longevity.

Hi, I am in a similar position. One thing that you would probably want to find out is what your walls are made out of. In my house, the structural element of the walls is cement block, so my house is considered a masonry house. Other people with brick exteriors have walls made of 2x4 studs. This will affect how the old windows are removed and how to install new ones. I would take out the entire aluminum window, frame and all, because aluminum is a horrible insulator. I recently replaced one of my windows and it took me about 3 days of work. I purchased an angle grinder with a cut off blade to cut through the aluminum window all around the edge. There is a flange that goes behind the brick on the outside and another one that goes behind the plaster on the inside. Additionally there were metal attachments that were mortared to the cement block and were holding the window frame in place. These attachments were not visible or accessible without cutting into the frame. I had previously tried to remove the frame by taking out all of the screws that I could see, but it would not budge at all, which is why I decided to cut into the window frame itself. Removal took about half a day. This is the first window I ever replaced in my life, so I was taking it slow and trying to think about every action I took, so that ate up a lot of time. I decided to attach a wood frame to the rough window opening before putting in the new window, so that took a good bit of extra time to cut, shave, paint and caulk. It was satisfying, but my wife says it took too much time and would like to hire someone to do all the rest of the windows. Do you live in a climate with cold winters? We have cold winters, and the aluminum windows just conduct the cold right into the house. You might want to have some contractors give you a quote, and ask them a lot of questions about exactly how they would tackle the job, they can be a wealth of information, and you may just decide to hire them as well.