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News blog21 April 2023

Near 0 Energy Buildings standards for the renovation of public buildings in Velenje, Slovenia

Near 0 Energy Buildings standards for the renovation of public buildings in Velenje, Slovenia

Addressing poor energy performance of public buildings is at the core of the EU Energy Efficiency Directive (EED) and Energy Performance Building Directive (EPBD) but it is also becoming a growing financial issue in central European countries.

The eCentral Project, in order to adress this issue, provides support to key stakeholders in better understanding benefits of nZEB (nearly Zero Energy Buildings). The aim is to prove that the nZEB approach, although innovative, is an optimal and cost-effective solution for the renovation and construction of public buildings.

The Project started in 2017 and will continue until february 2021. It is funded under the Interreg Program for Central Europe for a total budget of € 2,676,335.80. 8 partners from 5 European countries (Croatia, Slovenia, Hungary, Austria and Italy) are involved. REGEA, Regional Energy Agency of Northwestern Croatia is the leading partner of the Project. KSSENA, Savinjska, Šaleška and Carinthia Energy Agency is involved as one of the project's partners.



  • capitalise on results of previous and ongoing EU initiatives
  • develop an Energy Performance Certificate - EPC Tool for public authorities
  • deploy and promote innovative financing schemes
  • develop training programmes
  • assist nZEB projects
  • develop building renovation strategies
  • establish cooperation with scientific institutions and other nZEB initiatives



The project is developed in 3 pilot sites: Sveta Nedelja in Croatia, Budapest in Hungary and Velenje in Slovenia, where 3 pilot public buildings will be prepared for renovation in accordance with nZEB national standards to demonstrate the effectiveness of the latest technologies in energy efficiency, renewable energy sources, energy contracting and innovative financing schemes. The pilot projects will be implemented in three possible ways of financing: public-private partnership, energy contracting and mass financing.

In the example of Slovenia on the Velenje Pilot Site, project partner KSSENA is involved in the implementation of the energy renovation of the building used by University for lifelong learning (Ljudska univerza Velenje). The selected building has significant historical, cultural and social value for the local community. It was built in 1959 and beside occasional renovations, shows low energy efficiency and it is far from nZEB status.

According to the national action plan for nearly-zero energy buildings (AN sNES) for a building (valid for energy renovation of non-residential buildings) to be considered nZEB it must meet a threshold of 65 kWh/m2a along with a RER (renewable energy ratio) of 50%. The renovation would have to target an ambitious 65% of energy reduction compared to the current status, while the second condition is met as the building secures more than 50% from a highly efficient district heating system. To specify the investment, primarily a detailed energy audit would be required. After implementing proposed measures based on the feasibility study, the building will be under nZEB threshold, with energy consumption 58,5 kWh/m2 per year and cost saving of 4.673 EUR per year. Part of the calculated investment cost of 58.000 EUR are going to be covered by the project. The rest of 45.245 EUR will be fundraised by using combined crowdfunding approach: a crowdfunding campaign on a platform and traditional campaign collecting contributions as donations and sponsorships. The ESCO approach will be considered as a reserve option. 

The renovation of the building of the Andragogical Institute of the Lifelong Learning University Velenje started in 2020. The energy remediation investment is funded through three sources: the resources of the European eCentral project, municipal funds and contributions collected through crowdfunding.

In the first phase, the lighting in the building will be replaced and the parts of the building where the energy loss is greatest will be repaired (partial change of the porches). Solar power plant will also be installed on the roof, which will allow the use of electricity from renewable sources. The potential of crowdfunding is becoming recognised in the field of financing energy projects as a tool that can help accelerate the energy transition of countries and local communities into an energy-saving society and cleaner future. Crowdfunding can become a successful way of filling the gaps arising from the financing energy and environmental projects in the municipality, such as the reconstruction of the Lifelong Learning University.

If you are curious about the development of nZEB buildings in Central Europe, you can check the deliberables produced in the framework of the eCentral Project. A position paper on nZEB policies in central Europe has recently been published.


Publication date
21 April 2023