What is the most energy-efficient roof for my two-story home in a northwest suburb of Austin?

— Betty Saenz EcoBroker GREEN REALTOR Leander, TX

Answered by Alex Biyevetskiy on April 9, 2010

What are the sustainable options for re-roofing our 30-year-old home?

— Jennifer Marks, Tiburon, CA

Answered by Cynthia Phakos on November 26, 2008