Energy savings

In Houston, the number that matters is not the one they lead with.

Window marketing is built around U-factor, because that is what sells in cold climates. On the Gulf Coast, the spec that actually changes your summer bill is SHGC.

SHGC — Solar Heat Gain Coefficient

How much of the sun's heat comes through the glass, on a scale of 0 to 1. Lower is better here. A window with a low SHGC is rejecting heat before it gets into the room, which is the whole game in a climate where you are cooling nine months a year.

If a salesperson leads with U-factor and never mentions SHGC, they are selling you a window designed for Minnesota.

U-factor

How much heat moves through the whole assembly. Lower is better. It matters here — just less than SHGC. It earns its keep on the handful of genuinely cold nights and on keeping conditioned air where you put it.

Low-E coating

A microscopically thin metallic layer on the glass that reflects infrared. It is what lets a window reject heat without looking tinted. Different Low-E packages are tuned for different climates, and the right one for Houston is not the default one.

What to actually ask for

For a Houston home, you want a low SHGC, a Low-E package tuned for a cooling climate, and a frame material that does not conduct heat straight through. That last point is why bare aluminum frames are a bad idea here and thermally broken aluminum is fine.

What we will not tell you

We are not going to hand you a guaranteed monthly savings number. It depends on your insulation, your orientation, your shade, your AC, and how you live in the house. Anyone quoting you an exact dollar figure before they have seen the place is guessing. What we will do is show you the actual specs on each option so you can compare them honestly.