When we talk about how energy-efficient a building is, it is often the annual energy use that is discussed, since it is directly related to a cost for the owner.
But if we put the energy use in the perspective of the society as a whole, we should rather focus on reducing the peak power needed!
Our production sites and distribution systems have to be sized to handle the maximum needs, even if it only occurs for a few days each year. That makes both systems and buildings more expensive than they would be if we could keep the peak need down.
It also makes us more dependent of non-renewable sources of energy, since a lot of the renewable energy sources are low-temperature and cannot always supply enough power when the need for peak-effects occurs.
The peak effects are an important issue as well for entire urban district heating systems as for the single homeowner with a heat pump.
So what I would like to see and hear more of ahead is Power-Efficient buildings!