Why whole streets fog together
An insulated glass unit is two panes, a spacer, a desiccant and a gas fill, with a finite seal holding it together. The units installed across Columbus's boom subdivisions came from the same era of manufacturing and have been aging in lockstep ever since. When the seal goes, moisture gets in, the fill gets out, and the fog you cannot wipe off is the visible symptom of an invisible efficiency loss that started years earlier.
The builder-grade ceiling
The original units in most of these houses were chosen by a spreadsheet, not a homeowner. Replacement is the one moment the ceiling lifts: better frames, better glass, better installation, for a house you already know you are keeping. Installing the same builder grade again at that moment is the one mistake worth avoiding.
Air-tightness on open ground
Central Ohio wind does not just push on walls; it finds every gap around every opening. Infiltration ratings (the spec nobody reads) matter a great deal on open ground, and installation quality matters more than the rating. Level, shimmed, low-expansion foamed, and tested: the last hour of an install is where a window's winter performance is decided.
Historic exceptions to everything above
None of the subdivision logic applies in German Village or on Clintonville's older blocks, where the right answer is usually preserving profiles and sightlines while quietly upgrading the glass. Different problem, different products, same crew, and the review-board paperwork prepared with the quote.
Reading a failed unit before it fogs
Fog is the late symptom. Earlier ones: condensation between panes on cold mornings that clears by noon, a window noticeably colder to the hand than its neighbors, sashes that suddenly feel light because the gas fill is gone. Catching seal failure early does not save the unit (nothing does), but it lets you plan the replacement instead of discovering it in January.
Batch pricing, because the problem arrives in batches
Since seal failure sweeps a street at a time, we quote Columbus window work with clean per-opening arithmetic that scales. Doing eight now and four next spring should not cost more than twelve at once by accident. The itemized quote shows the count math so you can split the job across seasons deliberately.
One practical note from working these streets: replace the weather-side elevations first. West and south walls age fastest in central Ohio exposure, so if the budget forces an order, that is the order, and your quote will already be sequenced that way when it arrives.