**2.1 National buildings' energy performance certification tool**

The energy efficiency of the reference and designed building are determined by the following indicators:


#### **Figure 2.**

*An example of user's interface in national certification tool KI Energija with the presentation of energy balance for each element of heating and DHW heating system.*

renewable energy ones, therefore, non-renewable primary factors for fuels and total primary energy factors for electricity are taken into account. This means that primary energy delivered by renewable energy sources (solar, environment heat) will be equal to zero.
