Baseline Market Assessment: Energy Star High Efficiency Residential Windows

This study presents baseline information on the market penetration of U-35 windows, U-35 patio doors, and U-45 skylight estimates in the Pacific Northwest. Information came from surveys of window, door, and skylight manufacturers; high-volume builders of single and multifamily units; retailers of windows, patio doors, and skylights; and builders in the high-end remodeling business.