When choosing solid hardwood flooring it is important to understand the source of the wood and how it is processed into flooring.  The Forest Stewardship Council does most of the research for the consumers and certifies wood flooring products that come from sustainable sources.  Sometimes the more exotic species that are FSC certified are very expensive if they do exist.  An alternative to this expensive wood flooring is engineered hardwood flooring. 

Engineered hardwood flooring is made from multiple layers of soft plywood that is laid in an alternating grain pattern to increase strength.  This makes the material more resistant to higher moisture levels compared to regular hardwood floors.  The top layer is a harder veneer of any finish that is desired.  This is how the engineered wood flooring is more sustainable.  Instead of using solid wood of a certain species it only uses a thin layer so a significantly less amount of the tree is used to create the same look.  For every 1 square foot of solid hardwood flooring, 4 square feet can be manufactured in hardwood flooring. 

Overall, engineered wood flooring is sustainable for several reasons.  It minimizes deforestation and in many cases costs less.  It can be glued to an existing floor, floated, or nailed to a subfloor.  Multilayer ply is manufactured using low VOC adhesives that promote good indoor air quality.  Engineered wood is becoming a popular choice for those who desire sustainability and luxury.