My question might be answered by the fact that I cannot find a thread on this issue. We have 10 year old Renewal by Anderson window inserts that replaced old sash weight windows in our 1923 row house. We are now expanding the rear of the townhouse and would love to use up to 8 of our existing windows if at all possible because 1) they match the other 20 windows in the house and 2) they were very expensive, are still new and are expensive to replace. We're told that because they were used in sash window frames that the labor needed to recreate the frame for the new construction would not be worth it. Just double checking to see if all the creative power out there in TOH land might have any ideas to counter this, or if by some crazy miracle someone knows a place that creates sash window frames for new construction that would accommodate our "old" windows. Thanks!!