1. Water EfficiencyAs Bjarke Ingels shares in his prototype Martian "city" in Dubai, on planet Earth we have 1.5 billion cubic meters of water, while on Mars we only have 5 million, so we have to be incredibly efficient with how we use water. There is no ready-to-use water, potable water will be created through the heating of ice in the local ground soil, where water will be condensed and dry soil returned to its origin. A portion of this produced water is stored while a portion is used to produce oxygen.