We have the BiltBest casements - you will love the single lock. One thing we ended up doing - our architect had drawn in windows that were 6" larger than we ended up installing. Four rooms have very large windows on 2 or 3 walls to take in lake view. By going down 6", we went from "Mansion Series" size windows to the next lower cost level. Saved a small fortune. He had ALL the windows as functioning - we changed numerous windows to fixed to also cut cost. By doing these two things, we cut 30K from the window bid. Here's a picture of the breakfast area during construction (9ft ceiling):

Berkshire80, my windows were single pane aluminum inserts in the original wood frames, which where pretty beat up. Nothing to save there, so I ripped them out entirely and reframed the openings and put in vinyl with low-e glass. I resized the windows to standard 6" increments to save quite a bit of money. The inside walls (plaster!!!) are now a mess, but that will be fixed in "phase 3." For the corners just run the housewrap long a foot or so and tack it around the corner with roofing nails. It will hold until you get to that wall. I had one corner go like that all winter without problem as I sided a small area around the back door last summer when we replaced the roof, which by the way also had three layers of roofing on it. If you think three layers of siding is bad, try two layers of comp over cedar shingles. What a mess that was getting that off. Good luck with the project. I'm about two-thirds done. I should finish the east wall this week and that leaves only the north wall for the hottest part of our summer here. I started on the west wall this spring and worked around to the south wall. I generally only have the evenings and Saturday to work on it, so I tried to keep the sun away from where I was working as much as possible. I'll be very glad when I finish as this has been a real grind; however, the entire outside of the house will be new. Then I get to start on the inside.

I agree, afsa, we have been diligent about painting and caulking these all wood windows which I believe were either Huddig or Huttig (a local company which sold out to another local millwork company) for about 10 years now. I'm just tired of fighting against the elements. Every year I have rotten sills and rotten brick mold in the lower corners of the windows. I even had my painter remove the tracks that hold the sashes to caulk and paint behind them where water was obviously penetrating. The sashes are warping and the gas seals are failing, and worst of all there's wood rot in the sheathing below the windows behind the stucco . . . again!! I don't know if this is primarily a window problem, an installation problem, a stucco problem, or some of all, but my experience with all wood windows has not been good to say the least. Hopefully, new windows, installed and sealed properly will keep my home from becoming a bigger money pit! With all that we have spent on maintenance and repairs, we could have paid for at least half of our new windows by now. I a hopeful to find a solution :-)

Thank you all for your comments. I am still so torn because the trim on the siding is rotting away, especially on the back of the house that faces north. Granted, this wood is probably 25-30 years old... I am concerned that it will begin to rot again, when new wood is replaced. Our window sills are rotted and even windows are rotted. I assume this is from rain and maybe it can't dry out enough on the sides because the houses are close together? I just hate to waste a huge chunk of money on painting/staining the existing siding and have it all go to waste. It is going to be $18k to do the hazmat removal of the lead peeling paint, replace rotted wood and then put new wood siding on the addition. It's not like this is a $5000 job... Another concern is that I just found out a lot of moisture gets into the walls and seeps out of the house? Is this true? From cooking and showering? So this can cause the paint to fail prematurely if there is no vapor barrier, which there wouldn't be, since the cedar is original to the house in 1918. I also have concerns about going over cedar with vinyl for the same reason. I am concerned that mold could build up under the new vapor barrier that they would put up... I remember one siding company said it is a bad idea to not remove the old siding and this may have been why. We have had issues with mold in various places like under the front porch, but once proper ventilation was installed, it went away. I just don't want to have everything sealed up to the point that no water vapor can escape and is encapsulated in between the layers of siding, causing mold growth. I'm probably over thinking it, but we are stuck in which ever direction we choose, and neither is "cheap".