Gerkin.

Thanks.

Don Young Window are in texas, not that a road trip is out of the question.. But Gerkin is in Sioux City, IA or 5 hours west.

Let me ask a question please.

Thermally broken usually means the inside and outside frames are connected with a material that transmits heat or cold slower than aluminum if Im not mistaken. But I found a company in Des Moines called cornbeltwindowanddoor who advertise a "thermally broken" window, but the broken area is at the edge of the glass, and not between the inside and outside frame. Is this just another play on words?

Like I mentioned, a road trip is not out of the question if anyone has other suggestions.

What they appear to show is a slider that is built from 2 windows joined by a wood frame . The wood is the thermal thermal barrier. Looks to be poorly designed .

I am a huge fan of TBA windows, and it's the predominate product that we sell, but then I'm in Houston. I would personally never recommend it for Iowa. During the winter months you are likely to have condensation and even ice on the interior. If you are trying to avoid vinyl, you might look at fiberglass.

If you do go with TBA windows, it will be absolutely critical to ensure that they are airtight around the perimeter (spray foam) to avoid a thermal bypass with the air.

TBA windows?

Thermally broken aluminum.

We do not do windows but I have a lot of experience in this field. Thermally broken aluminum is a standard in Europe for decades now and these windows are quite easily available through dealers in the USA. You can even get them as Passive House Standard units from Schueco or Reynards or other companies. Zola windows for example offers them as well. Houzz is a great resource to find suppliers.