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EE-HIGHRISE Site Ljubljana


Project status



The objective of the EE-HIGHRISE project was to demonstrate and validate new technologies, concepts, and systems in order to test and assess the technological and economic feasibility of innovative energy solutions for high-rise buildings. The project used the Eco Silver House in Ljubljana (Slovenia) as a demonstration site.

The building is located in the city centre of Ljubljana, in the heart of a business, commercial and recreational area. The demonstration was implemented in the residential part of the building (12 870 m2 out of a total net area of 23 455 m2), which consists of 11 floors with 128 passive-house-standard apartments. The Eco Silver House was designed to fulfil the requirement for the passive standard (PHPP07).

The fundamental principles of sustainable development of a high-rise building were reflected in EE-HIGHRISE through comprehensive planning of energy-efficient savings, along with renewable energy sources, thermal insulation, wall soundproofing, an air conditioning system, sun protection, air-conditioning appliances, intelligent control and management of electric and mechanical devices, machinery and tools, ecological materials, use of rainwater, solar power station on the roof and a green roof.

Within the project timeline, an interactive model of the Eco Silver House was created as a virtual building and made available online. It enables stakeholders in the sustainable buildings field to visit the Eco Silver House demonstration building via the internet for free, providing extensive information about the design, construction and operation stage of the Eco Silver House as well as the different sustainable systems, processes and outcomes, the knowledge and practices gathered within the EE-HIGHRISE project.

Demo Site Expected Impact

*The KPIs for the new building are compared with the baseline of a reference building.

As a result of the energy efficiency, the space heating in Eco Silver House was reduced from 105 kWh/m²/yr (business as ususal) to 21 kWh/m²/yr, while electricity consumption was reduced from 28 kWh/m²/yr (business as ususal) to 23 kWh/m²/yr. Together with the domestic hot water, the total consumption went from 143 kWh/m²/yr to 51 kWh/m²/yr, representing a decrease of more than half in comparison to a reference building. This makes for 2109 MWh/yr of final energy savings. According to the primary energy and CO2 factors of Slovenia, the primary energy savings goes up to 2239 MWh/yr while the CO2 reduction amounts to 937 tonnes every year.



*The KPIs for the new building are compared with the baseline of a reference building.

The most important innovations of EE-HIGHRISE are the integration of the building envelope, HVAC system, intelligent integrated control system and renewable energy sources, fulfilling the passive standard for a high-rise building. The implemented measures include:

Energy efficiency in buildings

  • High-performance new buildings

    • Thermal isolation and sound isolation of walls
    • Sun protection measures
    • Intelligent Control Centre for the management of electric and mechanical devices, machinery and tools
    • Use of ecological materials for a healthy environment and high living comfort
    • Air-conditioning with time-defined operations
    • Use of rainwater for toilet flushing to save drinking water
    • Green roof
  • Building integrated renewable energy sources
    • Solar power station on the roof, which produces 33 MWh of electricity per year

Energy systems integration

  • District heating and cooling

    • Each apartment has its own heat substation for space heating and domestic hot water
  • Waste heat recovery 
    • High-quality ventilation system by a recuperator, which enables the restoration of the waste heat. System efficiency of 85 % heat recovery was achieved, which is reflected in cutting the heating costs by half, compared to the reference value, and ensuring high living comfort and good air quality.


  • Building energy management system

    • Intelligent Control Centre for management of electric and mechanical devices, machinery and tools

The total investment for the EE-HIGHRISE building amounts to EUR 17 148 078, whereas the reference building costs are estimated at EUR 15 922 077. The energy-related higher investments that are included amount to EUR 1 226 000. The total energy savings add up to EUR 77 900 per year, which means that the higher investment can be paid off by the energy savings in 16 years.


Marjan Strnad

Building aspects

  • Building Energy Services
  • cooling (only)
  • Building Energy Services
  • heating and DHW
  • Installed Renewable Energy Sources
  • photovoltaic - building integrated
  • Technology used to supply the buildings
  • district cooling (DC) network
  • Technology used to supply the buildings
  • district heating (DH) network

Thematic Field

  • New Building(s)
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Project data