Replacement windows have been developed as a labor and cost-cutting alternative. There are two main types of replacement windows:

• "Flush fin" (also called Z-bar or Retro-Fin) replacement windows are typically used in California and other markets with aluminum windows in stucco home exteriors. This method leaves the original aluminum window frame intact and provides very little opportunity for the stucco siding to be damaged. If you and your contractor choose this method, be sure to ask to see photos of Z-bar products installed in a home like yours so you can visualize the results.
• "Block frame," or insert replacement windows, are typically found in markets where wood windows are in place, and the exterior is siding or brick. In most parts of the country, the block frame window is simply a new construction window frame with the nail fin removed. Your contractor will want to ensure that there's been no damage to the studs and there is proper insulation and flashing before using this type of window.