
Windows let the light in... and perhaps a lot more.
With the colder months approaching, home improvement companies are advertising their “window replacement specials”, implying that replacing your current windows will result in hundreds of dollars in energy savings. The question is, can you really save that much money by replacing windows? And what do I look for when I see replacement windows during a home inspection?
When I see replacement windows I ask WHY…
There are many reasons for replacing windows, especially in older homes. Since a home inspector usually doesn’t have contact with the home’s current owner, much of what we can report is in the form of questions for the buyer to ask.
Was it lead paint abatement?

Presence of lead paint can prompt window replacement.
In many old houses, the windows and trim were painted with lead paint. Rather than the mess and expense (not to mention health hazard) of stripping and repainting the existing windows, the owner can choose to remove the entire window and replace it, trim and all.
Was it an old wood single pane window that didn’t move easily and was drafty?
Draft prevention may do more to increase the comfort level in a home than adding extra insulation or replacing windows.
Did they fix the OTHER sources of drafts?
Were gaps in the baseboards and around the doors also filled? Are drafts still coming through the outlets? Sometimes such “partial” fixes can speak volumes about the maintenance of a house.
Was this part of a larger renovation?
Was there other work done at the same time, such as a new kitchen, or addition, or other modifications to the home?
Do all the windows match?
Windows should match in style and trim. If one or two don’t, it’s worth asking why. Also, if there were multiple replacements, note whether any were missed (such as false dormer windows or basement windows).
Did they replace the entire window, or just the sashes?

For this replacement, the entire old window was removed. leaving the original rough opening.
Full replacement windows required removal of the entire existing window, including sashes, frame and trim, so the new window has the same dimensions as the old one.

Insert replacement window (from Family Handyman magazine)
There is also the “insert replacement window”, which is installed in the original window frame. While these can be less expensive, they also have some drawbacks: there is still the possibility of lead paint exposure, and they don’t address any draft issues around the edges of the existing frame. The insert type also reduces the glass area of the window and requires much wider trim to cover up the discrepancy.
Are they “first Generation” vinyl windows that rot in sunlight and crack?
Windows are exposed to the elements, and early vinyl windows were found to be prone to UV damage. It’s important to know when the windows were replaced. Some windows will have a date stamp somewhere on the frame or glass.
Do they work? Are they fogged? Can you still get parts?

All windows need maintenance to function properly.
Any window, new or replacement, needs maintenance. For older windows, it may be difficult to find parts to repair them. There are companies which specialize in window repair, but be warned: it can be costly! Replacing a broken sash cord can cost well over $200 per window.
Other issues
Replacement windows can be considered a “property improvement”, which could mean adhering to a building code different from the original window. The biggest issue with is is the use of tempered glass where required. Replacing a window generally doesn’t require a permit because it is a “like for like” issue, but codes may still come into play.