Nothing says sustainability more than preserving, restoring and repurposing existing buildings. The greenest buildings today are those already built. Masonry is a sustainable, resilient material that can survive floods and fires. It is the oldest and most permanent building material, exuding a sense of permanence, longevity, quality, reliability and familiarity, yet it is forgiving and flexible. Many brick buildings that were built more than 100 years ago are continuing to fulfill their original purposes, while others have been adapted for new purposes.