Building a new house south of Houston, and trying to make window decisions. The house has 29 windows in various sizes, all double hung, all simulated divided lite, all clad exterior (except Marvin Integrity). The smallest is 3'x4', the largest is 4'x8'. Most are in the 15 to 20 square feet size, e.g., 3'x6'. Total nominal window square footage is about 575 sqft.

We are still in the design changes, so window count and sizes will probably change. So instead of asking for bids on the current window package, I got bids on a single 3'x6' window from several dealers/manufacturers (but no more than one per manufacturer so far) to be able to make a relative comparison. Each bid was for one window with impact rated glass and one without impact rated glass ("IR" and "non-IR" below). Each window is windstorm approved by the Texas Windstorm (a requirement). Here's what I got...

Marvin Ultimate: IR - $1900, (didn't receive bid for non-IR)

Marvin Integrity Wood-Ultrex: IR $1400, (didn't receive bid for non-IR)

Kolbe Ultra: I.R. - $1700, non-IR - $800

Pella Architect: IR - $1630, non-IR $730

Jeld-Wen Siteline: IR - $1185, non-IR $880

I plan on getting impact rated glass (but don't want to get into that discussion right now), but I was curious as to the "upcharge". That's why I asked for non-IR prices. As a side note, I recently had about 25 windows (almost all 3'x6') replaced in an existing house with vinyl windows (same "details" as above, e.g., impact rated glass), and the upcharge for impact glass was a little under $300 per 3'x6' window.

My question is... why is the upcharge for some manufacturers (Kolbe, Pella, and I assume Marvin) so high compared to others (Jeld-Wen, vinyl windows)? They all admit that they use the same glass (Cardinal, double, insulated low-E, impact rated).