The sites below contain the wealth of knowledge that may be useful to your research.
Windows
www.efficientwindows.org
www.vinylreplacementwindows.org
www.energystar.gov
www.nfrc.org
www.aamanet.org
www.installationmastersusa.com
Residential Windows:
A Guide to New Technologies
and Energy Performance (Third Edition)
www.alside.com
www.oknawindows.com
Siding
www.vinylsiding.org
www.progressivefoam.com
www.chooseinsulatedsiding.com
www.alside.com
Doors
www.proviaproducts.com
www.thermatru.com
