Insert or full-frame comes first
An insert replacement sets the new unit inside the existing frame — less disruption, lower cost, and the right call when that frame is square, sound and dry. A full-frame replacement strips back to the rough opening and rebuilds from there.
Which one your house needs is a measurement, not a preference. Soft sills, racked frames or staining around the casing all point full-frame; covering them with an insert seals the problem in.
The glass does the energy work
Two numbers describe most of what a window does: U-factor, how well it holds heat in, and solar heat gain, how much summer sun it lets through. Low-E coatings and gas fill between the panes move both.
A climate with real winters and real summers needs the two read together — a window chosen only to hold heat can cook a west-facing room in July. We go through the label with you, not around it.
Fitting decides more than the brand
A well-made window fitted out of square fails early: sashes drag, seals stress, water finds the sill. The parts you never see set the service life — flashing lapped the right way, shims that keep the frame true, insulation that fills the gap without bowing the jambs.
It is why every opening is measured on its own rather than averaged from a floor plan.
When a window is actually done
Fog between the panes means the seal has failed and the insulating gas is gone — that unit is finished even if the frame is fine. Sashes that will not stay up, softening sills and drafts you can feel are the same verdict in other forms.
One failed unit does not always mean a whole-house job. The inspection separates the windows that are done from the ones with years left, and the quote follows that line.