In South Africa, energy sufficiency is quite important and a number of factors in this regard is discussed in this document for the Cape Town city council
"minimizing your footprint" can be an all-rounder in the sea of eco sustainability, taking into 7 billion (and counting) possible footprints on the globe.
A sustainable building should first be naturally comfortable, so that it could be inhabited by happy people for a long time. "Naturally comfortable" means that the indoor environment quality is obtained mostly with passive, architectural measures. It follows naturally that the energy use will be strongly reduced. In addition, the materials used should have a low footprint and/or be fully recyclable.
In short, I would refer this to a comfortable building with lowest life cycle cost and lowest embodied energy.
Comfortable takes care of thermal conditions and IAQ, life cycle cost takes care of initial as well as operational cost in terms of energy (may include use of renewables), and embodied energy would take care of use of sustainable and local materials.
A sustainable building should be addressed to the 3 items of People, Planet & Profit.:
1. The people should be happy people for a long time, just as Claude-Alain wrote.
2. The planet aspects are related first to a very long lifetime of buildings but at such a way that the building will bw adaptable. We call it the capacity to change. Furthermore answering the aims of C&C and Circular Economy)
3. The Life time Cost of the building should be affordable also at the long term.
I agree with Srijan Didwania. So we have to optimize the design on the points of comfortable building(very subjective and highly dependent on regional parameters) with lowest life cycle cost (locally available materials) and lowest embodied energy(low energy intensive again vernacular building materials). If we emphasise on any one the resultant building will not be sustainable. Best examples are the vernacular architecture spread across the world.... and provide lot of opportunity to learn....
§ Reduced the carbon footprint in accordance with buildings targets.
§ Reduced water consumption in accordance with buildings targets.
§ Improved Environmental Sustainability leadership and culture throughout the buildings .
§ Provided high quality, consistent and practical Environmental Sustainability information and advice to the Medical City community
§ Reduce or eliminate toxic and hazardous substances in facilities, processes, and their surrounding environment.
§ Improve indoor air quality and interior and exterior environments, which will lead to increased human productivity and performance and better human health.
§ Select materials and products that will minimize safety hazards and life cycle environmental impact (e.g., local materials and lowest embodied energy materials).
§ Recycle and salvage construction waste and building materials during construction and demolition.
§ Implement maintenance and operational practices that reduce or eliminate harmful effects on people and the natural environment.