The energy design of a building is the basis for its expected future dependency on fuel resources and consequently a considerable part of the expected future running costs. When building costs are discussed the argumentation is commonly limited to construction costs. With an increasing relevance of energy prices and more and more investors asking for certified buildings, operation costs and even costs for deconstruction become more and more relevant. Depending on the specific building parameters such as usage type and location, future costs can make up to 80% of the total lifetime costs of a building.
A smart energy design does not only consider minimised heat loss via the building envelope so that very little energy supply is needed in operation, it also seeks to make best use of the building geometry, its thermal mass and how solar energy is efficiently made available for the building users. A smart energy design aims at creating a comfortable indoor climate, in a way that very little energy is needed to keep a comfortable indoor air temperature. Once the energy demand is reduced, efficient systems for securing the supply of the remaining energy are added to the system – preferably using renewable sources like solar energy to increase the independency on fossil fuels and minimise CO emissions.
This strategy is not only basis for legislation in various European countries and for many architects, it is also a very simple principle everyone will normally apply in every day’s life: In order to keep coffee at a warm temperature it is usually put into a thermos flask (which minimises the heat loss) rather than put on a heating plate (which would demand continuous heat supply). The approach is commonly known as the Trias Energetica.