Rotted sills are pretty commonplace and most of the rot that people see is often times draining behind the exterior cladding of the home and therefore not rotting structure. You need to take a closer look (i.e. remove some exterior cladding and inspect structure or remove the sill and take a look at the rough opening). While the rot may look significant, a majority of what is out there is non-structural and therefore does not require a full tear out. If you go full tear out, you absolutely should use a flanged/new construction window. Having asbestos siding certainly complicates matters a bit and you would be well advised to check code requirements as it pertains to that specific ACM (Asbestos containing material). There are more stringent requirements if the material is removed professionally (i.e. by a contractor) as compared to the homeowner (not all together dissimilar than the RRP fiasco).

You can replace just the glass with new integrated glass units from your local glass supplier. Measure your existing ICUs carefully and the new ones will fit like a glove. You can repair and paint the sills. I'm not that sure about power washing. I think a scraper to remove the loose paint, a little sanding and new paint are more like it. In any event, you use replacement windows to replace windows, not windows designed for new construction. You would have to remove the siding to install them properly.

What kind of windows do you have currently...wood, vinyl, metal, etc? There is nothing about new construction that = better insulation as compared to an insert. Going new construction will net you a bit more glass and can provide for a more complete and comprehensive installation if done properly. If you are pulling the siding, that would be the time to undertake the window replacement if you decide to go full new construction and nailing flange.

I am replacing the siding and windows on my entire Wisconsin home built in the70s. there are 19 windows. Yes I’m getting rid of the brick... complete exterior remodel. 1)since i am doing siding, do I do new construction windows or do I do vinyl inserts 2) there are so many window manufacturers, can anyone tell me which windows I should consider for this house and which ones I should not put in my house..? I habe heard That plygem is an average company and I have also heard it’s not recommended. What about hayfield out of MN or alliance ? thabk you 2