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

Green roof to offset the required land space for zoning?

— feng schaefer

Answered by Kathy Spence on February 2, 2010

Are there any cost-cutting shortcuts for planting a green roof on my urban townhouse?

— Rachel Diamond, Harrisburg, PA

Answered by Mark Schrieber on August 25, 2009

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