From the HUD Office of Policy Development and Research:

"The following matrix highlights 10 proven and affordable green building technologies organized into four categories: Building Envelope, HVAC, Management and Use, and Water. Each product features a brief description for general reference; technical overviews are addressed by the resources highlighted in the 'Additional Information' section. These entries have a track record of providing savings, are affordable across building types and scales, and are viable in diverse climates. This document is not intended to be a comprehensive exercise in quantifying green building strategies or elevating every high-return-on-investment (ROI) product. Instead, it is a simple, accessible, cogent tool to educate and motivate builders about the nuanced economics of green building."

For more information, read the full matrix and report