A high performance home is designed to be as durable and efficient as possible.  Materials are built to last, rather than built as cheaply as possible with a dash of lipstick painted on.  

A high performance builder considers costs over the entire life of the home, whereas conventional building is generally focused on initial design and keeping construction costs low for the builder.  For example, a residential home developer may scrimp on insulation to save money without considering how that impacts the energy costs of the future homeowners.