The answer is passive strategies. Passive strategies are what make the thermos flask different from the coffee machine. The coffee machine needs to be actively kept warm because it is losing a lot of energy to the outside environment. Meanwhile, the thermos flask doesn’t need any additional energy to keep the heat inside thanks to its high-quality envelope. Thus, the thermos flask is much more energy efficient than the coffee machine. The same principle can be applied to buildings. Improving the energy efficiency of a building can result in over 90% reduction in the energy consumption for heating and cooling in contrast with the consumption required for a standard building.
Moreover, energy efficiency is stimulated by governments over the world. They do this through incentive schemes for energy savings, subsidy programs, policy changes etc. In the European Union, for example, energy efficiency is encouraged with policy changes. The Energy Performance of Buildings Directive requires all new buildings in the EU to be nearly zero-energy by the end of 2020 and all new public buildings must be nearly zero-energy by 2018.
So… Which energy source will dominate the future of the built environment? The global trend is to reduce carbon emissions and fight climate change. The best way to do this is to focus on energy efficiency first and cover the remaining demand with renewable energy resources.
…Because the most sustainable energy is the one not used.