What is the best method for installing new construction windows on a 1953 ranch home? We're planning to re-side w/Hardie Plank & install wood new construction windows w/nailing fins, exterior of windows to be trimmed in Azek. My contractor recommends replacing all of the wood trim & sills on the inside of the house, too. Inside trim is in good condition and surely doesn't look worn or rotten. Is it wrong to install new construction windows and leave the original inside wood trim & sills intact? We do not want replacement windows. Please advise.