One of the dirty secrets of product design is that most products end up as landfill. Even worse, much of those land-filled products still work, but are simply obsolete, worn, or out of fashion. For many products, one of the best things you can do is to extend its life. Giving your product twice the life is equivalent to using half as much material; giving it ten times the life is equivalent to using a tenth the material. Such huge material reductions are nearly impossible to do even by the best engineering, but good design can achieve it without even using high technology.
Of course, the tricky part of design for lifetime is that it’s not just a matter of your product lasting longer, it’s a matter of people using it longer–staying up-to-date and attractive as well as being functional. Or it’s a matter of it being easily transformable into new products that people will use and love.