Signs You Need New Windows

You likely need new windows when there is fog between the panes, drafts around a closed sash, water stains at the sill, or sashes that stick or will not lock. Frost or condensation on the room side in an Iowa January is often a humidity issue instead, so it pays to know the difference before you buy.

Fog between the panes

Fog or haze trapped between the glass is the clearest sign. This Old House quotes general contractor Tom Silva: moisture between the panes of a double-glazed window is a sure sign that the seal around the perimeter has broken. This Old House says fogging alone may not cut performance much unless the glass has a soft low-E coating, but it will not clear up, and removing it means replacing the sash or the window. Once one unit fogs, others of the same age often follow.

Drafts and cold rooms

Hold your hand near a closed sash on a windy January day. If you feel moving air, the weatherstrip, the frame or the seal between window and wall has failed. The U.S. Department of Energy says windows can account for 30 to 40 percent of a home's heat loss in winter, even though they are a small share of the wall. In This Old House's 2025 survey, energy cost savings was the top reason homeowners replaced windows, at 42.9 percent. Drafts that remain after new weatherstrip and caulk point to replacement.

Hard to open, close or lock

This Old House lists windows that are difficult to open, close or lock as a sign it is time. Swollen wood sashes, broken balances in double-hung windows and stripped casement cranks are common. A window that will not lock is a security issue, and a basement or bedroom window that will not open is a safety issue, because it may be your way out in a fire. Some hardware can be repaired. When the frame itself has warped, replacement is usually the fix.

Leaks and water stains at the sill

Water stains on the interior frame, peeling paint on the sill or warped flooring under a window can signal a serious leak, according to This Old House. Outside, look for soft wood at the bottom corners of the trim, gaps in the caulk and siding that is stained below the window. Leaks often come from failed flashing around the window, not the glass, and a new window set without proper flashing tape will leak again. Full-frame replacement lets us see and repair the framing.

Winter condensation: when it is normal

Iowa winters bring frost and water on the inside of the glass. This Old House says normal condensation when indoor or outdoor humidity is high is not a concern by itself. The key is where it forms. On the room side, it usually points to high indoor humidity, and a run of the bath fan or a lower humidifier setting often helps. Between the panes, it means a failed seal. Ice that builds on the frame itself, or water that runs down and rots the sill, is worth a closer look.

Age and frame material

This Old House gives typical lifespans of 20 to 40 years for vinyl, 30 to 50 for fiberglass, and 15 to 30 for wood and aluminum, and says real life depends on materials, upkeep, climate and installation. In its 2025 survey, 47 percent of replacements happened in homes more than 20 years old. Angi says most properly installed windows last 15 to 20 years. Age alone is not a reason to replace, but old windows with several of the other signs usually are.

Noise, fading and an outdated look

This Old House also lists outside noise, worsening allergies and an outdated style as reasons people replace. The Department of Energy says triple-pane windows cut perceived noise by roughly half in its research. If you are planning new siding, replacing windows at the same time lets us flash both together. When you are ready to price it, our window replacement cost guide lays out the published ranges.

Common Questions

What to Do Next

If two or three of these signs sound familiar, it is time for a closer look. Call or text Luke at (515) 901-3646 or see how we replace windows, and we will give you a free estimate.

See our windows service or call or text (515) 901-3646.