Part I of this article discussed the two common replacement window options which are full frame windows and insert windows.  Part I described in detail the process and the window components that are replaced with each of these options. Part II discusses the general circumstances that indicate when each of these replacement window options will likely be the most appropriate choice.

The appropriate replacement window option (also called application) should be determined based on each home’s unique circumstances. There is not one option that is appropriate for all situations. Homeowners should thoroughly understand the issues related to the windows that are to be replaced including: (1) the overall condition of the window frames and window sash, and (2) the primary problems that need to be addressed, i.e. rotten window sash and frames, air leakage, windows that don’t open and close properly, fogged glass and/or poor energy efficiency. The material that the existing windows are made from, i.e. wood, aluminum, composite or wood-clad, may also be a factor. Homeowners also need to determine if it is a priority for the exterior of their windows to be virtually maintenance free.

Insert windows, also called pocket windows, are probably the most familiar replacement windows to most homeowners because they are the most widely advertised replacement window application.  Insert windows are a good choice when existing wood window frames are in excellent or good condition and converting the exterior trim to a maintenance free material is not a priority.  This is commonly the case with historic homes where retaining the original trim is often considered important.

An insert application is also often recommended in circumstances where the primary issue relates to improper operation of the window, but the exterior frame is wood-clad or composite and in good condition. Insert windows are also usually recommended to replace aluminum windows. Insert windows are appropriate for situations where the amount of glass in the window can be decreased without negatively impacting the appearance or feel of the home. The impact of decreasing the amount of glass in the window opening is most apparent in small and/or narrow windows.

Full frame windows are generally less familiar to homeowners because they are not as widely advertised and not all window companies have the capability to expertly install full frame replacement windows. Full frame windows should usually be recommended in circumstances where existing window sash and frames are in poor overall condition and require extensive repairs. This is often seen in hot humid climates that lead to rotting window frames and fogged glass.

Full frame wood-clad or composite windows are also the most appropriate in circumstances where homeowners wish to replace wood windows with a virtually maintenance free exterior finish. When a maintenance free exterior is the priority, wood-clad or composite full frame windows are a superior choice to an insert window with the original brick mould being wrapped with trim coil.  The wood-clad or composite material is superior because the trim coil material used to wrap the brick mould does not create a weather or moisture tight environment.

Full frame windows should also be used in circumstances where the homeowner does not want any decrease in the amount of glass in their windows.