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EU-GUGLE Site Bratislava


Project status



Bratislava is the capital of Slovakia and the country’s largest city with a population of about 475 000. Located in south-western Slovakia, the city occupies both banks of the Danube River (centre of the city) and the left bank of the Morava River (west part of the city).

The apartment buildings selected for the EU-GUGLE project demonstration are located in two districts: the wider city centre and the western part of the city. The total area to be renovated is 40 000 m², and features a wide range of different building types with different construction systems and construction materials from 1960s onwards, representing a typical city building composition. Almost all of the selected buildings were characterised by high-energy demands and diverse technical difficulties. The envelope had insufficient thermal protection and required a high amount of energy for space heating and domestic hot water preparation. Most of the buildings were connected to a district heating network.

The selection of pilot private apartment buildings aimed to identify the wide spectrum of issues and problems that could occur in the renovation process of housing stock in the city.

Demo Site Expected Impact

* Information regarding the technical and economic performance will be available at a later stage.

The energy consumption figures amount to around 165 kWh/m²/yr before the project and less than 50 kWh/m²/yr after the interventions will be implemented. The energy saving measures are expected to result in 60 to 75 % reduction of energy use in buildings In addition, the interventions will improve the quality of life of the inhabitants and raise their awareness of a correct renovation of properties, regardless of historical or contemporary buildings and environmental issues in general. The measures will be replicated in other apartment buildings, located in different city districts with similar building types in terms of construction materials and construction systems.


Buildings and energy

* Information regarding the economic performance will be available at a later stage.

The measures implemented in Bratislava are:

Energy efficiency in buildings

  • Retrofitting the building envelope
    • Improvement to the energy performance of buildings through renovation and retrofitting measures, such as thermal protection of peripheral constructions, roofs, replacement of existing windows with triple-glazed windows
  • Building services (HVAC and lighting)
    • Retrofitting of the building’s technical system components and thermal insulation of distribution system pipes
    • Mechanical ventilation system with heat recovery
  • Heat pumps

Energy systems integration

  • Thermal collectors
    • New energy source after disconnection from district heating
  • Photovoltaics
  • Cogeneration (CHP)


  • Building energy management system
    • Introduction of metering and regulation control systems


Zuzana Hudekova
City of Bratislava

Building aspects

  • Building Energy Services
  • heating and DHW
  • Installed Renewable Energy Sources
  • photovoltaic
  • Technology used to supply the buildings
  • district heating (DH) network
  • Technology used to supply the buildings
  • heat pump: compression
  • Technology used to supply the buildings
  • thermal storage

Thematic Field

  • Refurbished Building(s)


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