entire life cycle of the product, service or built environment issue ofinterest. As an example of applied engineering principles, the foundation idea of this type ofassessment is the “material and energy” balance. Scope&of&Interest&is&Across&the&En1re& Product,&Process,&or&Project&Life&Cycle& M, E! M, E! M, E! M, E! M, E! M, E! R! !w!! a!! ! !! !! a M! t erial M! !t! ! !! !! a er ia l M! !n! !a! !u