Unless you are going to pull off all the siding on the exterior, seal everything up, and re-side, there isn't much net effect/benefit that you will make on that end of things.

Honestly, best thing you can do is air seal and insulate the attic. That will decrease the drafts around all the windows and doors as well as make the home tighter in general.

The issue probably has more to do with the fact that they are cresline windows ( low quality). Investing in a higher end vinyl window will solve most of the problem. We have changed out hundreds upon hundreds of 10-15 year old crestline windows with great results. My customers always tell me it was well worth the extra cost.

by the way, we do a standard replacement with foam. No need for a full tear out unless there is a lot of water damage and wood rot.

Thanks to both of you. A couple of follow up questions:

1. Can you please explain how adding insulation/fixing air leaks in the attic help the window leaks?

2. What is a better brand of windows to replace the Crestlines with? I'm not looking for "top of the line"....just something better (best bang for the buck).

3. How much should I budget per window for replacement (ballpark)?

4. Is this something a DIYer can do? I am very handy and have all the tools. I've built decks, worked on finishing basements, etc in the past).

Thanks Windows! Can anyone answer my questions 2 through 4 above?

Window options are somewhat regional. The better brands in our area are Soft-Lite Elements, Sunrise Restorations, and Okna Envirostar.

Budget totally depends on area. Best bet is to just get some quotes on several windows in a category that are of similar performance and see how they compare.

Possibly. The bigger issue is the trim work on the outside. It requires a more specialty tool set and is a bit of an acquired skill. If the windows you were replacing were wood, the process is less specialty intensive.

I worked on the windows some this weekend. I took a leaf blower and blew air against the window from the outside. Using an incense stick inside, it seems the windows are leaking around the lower sash. I then pried off the trim/track where the lower sash slides up and down on (this track compresses in so that the lower sash can be removed). I also removed the trim where the bottom of the bottom sash meets the sill. The tracks on the sides have a very light foam in them and the bottom trim was empty. The only caulk anywhere on the windows are on the bottom corners where the side track meets the bottom trim (this was installed by the Crestline rep after we originally complained). I also found a lot of dirt inside both these so obviously air is entering them. So I think this might be a large part of my issue. Here are some pictures:

Side track with light foam

Side track with light foam (notice the dirt on the foam)

Picture of track with lower sash installed

Bottom trim (hole with dirt in it is where the side track normally fits in)

Bottom trim removed

Bottom trim and side track removed

So I am wondering the following:

1. Is the hollow bottom trim and very lightly insulated side track normal? Do you think this is where my problem is?

2. Can I insulate these? If so, any suggestions?

3. I'm assuming caulking better would help too? If so, where do I need to caulk?

Thanks!

1. Normal, not on most windows. Seems to be a bit reverse engineered if you ask me. You problem is more in the design of the window to be honest.

2. You could insulate that side track with some additional compression foam, but do not run it near the bottom of the track. That will obstruct drainage and create issues for the window.

3. You shouldn't need to caulk unless the window has a broken weld and is leaking water.

Thanks! What about the bottom trim piece (where the bottom sash meets the frame/sill)? Can I insulate that with foam too or will that obstruct drainage?

Amigo, the best installer in our universe wont fix that window. Those windows are below builders grade and thats being nice. I would seriously consider investing in a quality replacement window by a highly rated window company.

those are some poor quality windows.

Can't afford new windows now so that's not an option. Thanks though.

Don't put anything under the sill piece. You need everything there to drain freely.

In this instance would a storm window help? Specifically I'm looking at the Larson windows:

https://www.larsondoors.com/storm-doors/product-details?CG=88

https://www.larsondoors.com/storm-doors/product-details?CG=87

I would take the storm money and start replacing the vinyl.

+1

Spending money on some storms is like spending good money chasing bad in my opinion. There isn't much about that primary window that is worth salvaging to be honest. Sorry for the negative outlook, but it is mostly the truth.