The more I learn about windows, the more I am sold on Fiberglass windows. Thermal rate of expansion issues are completely bypassed and I think this is the cause of most failures. The thermal performance of fiberglass frames is incomparable. For the Perry Road project we are looking at: Integrity by Marvin Windows - www.integritywindows.com

Acurate Dorwin out of Canada offers tunability of glazings so you can get more solar heat gain in our Northern climate on south facing windows (American windows are all about blocking heat gain. www.accuratedorwin.com

Fibertech - just started looking at these. www.fibertec.com

thermotech - these seem really nice but no double hung. Seems rather myopic to me. Around here we have our windows open 5 months of the year and sometimes you need a double hung

No idea of pricing and lead times yet.

I'll let you know how it goes