How to define adequate boundary conditions
The duration of the period under consideration, the future energy price increase, as well as the consideration of interest is essential for assessing the economic advantageousness of an energy related modernisation. For this purpose, different conditions may be chosen depending on the available data, the state of knowledge, and the perspective.
Static procedures only take into account a few of these conditions, but price increases and adequate target rates, for example, are not considered. Dynamic procedures offer a better assessment as they also take into account different future developments (among others, increases in energy prices) through boundary conditions. Sensitivity analyses with different scenarios, such as for energy price increases, may be useful in individual cases.
The boundary conditions, on which the release of the current Energy Saving Ordinance was based, can be found here. The following conditions may be chosen as examples in course of economic assessments of energy modernisation measures in buildings. In individual cases, it may be useful or necessary to choose different conditions.
|Boundary condition||Possible settings|
|Period under consideration|
Technical lifespan or default value:
|Lifespan of measure||see table "technical lifetime"|
|Adequate target rate|
|Increase of energy price||Orientation along official predictions or default value:|
e. g. 3.5 %/a (nominal)
|Inflation rate||2.0 %/a (nominal)|