The answer is simple, one that provides a high level of thermal comfort without an over reliance on artificial heating and cooling.
Also I would like to note that it is not enough to simply employ materials with high thermal mass. A well-designed passive house uses all of the principals of passive design to maximum advantage, and includes orientation, ventilation, insulation and mass.
Sustainable development satisfies the needs of the present generation without compromising the chance for future generations to satisfy theirs.
