Oborishte (Sofia)

The Oborishte district is one of the older parts of the city of Sofia, the capital of Bulgaria. Within Oborishte, there is a mix of residential, commercial and office functions, as well as a mix of building types (pre-war detached houses, multi family apartment blocks). This action envisages the renovation of five apartment blocks that are rather typical for building practice both in Sofia and Bulgaria around 1970. The buildings are prefabricated apartment buildings with 7 to 8 levels, locally known as ‘panel blocks’. Thermal characteristics of the constructions are very poor, large parts of the glazing are in poor condition. The same can be said for the common parts of the blocks.

Caption Photo

Energy efficiency in buildings (RUE)
The energy demand of the blocks will be reduced drastically by improvement of the building envelope by replacing windows and adding insulation, which will give up to 70% energy savings for space heating. Overheating is a serious problem in Bulgaria. Sun shading devices will reduce the overheating problem and thus prevent the purchase of air-conditioning units. Thirdly special attention will be paid to the reduction of the household electricity consumption, which is rapidly growing in Bulgaria nowadays.

Sustainable energy supply (SES)
The domestic hot water system will be separated from the district heating system. On the roof of the buildings solar energy systems of in total 600 m2 will be installed. Solar thermal collectors will supply the domestic hot water for the flats in days when the solar energy is enough and together with gas- fired boilers when the renewable energy is not sufficient. Disconnecting the hot water system from the district network will improve the overall efficiency of the network considerably.

Integration of SES and RUE
Reducing the energy demand for heating and cooling is the first step and a condition for a successful integration of sustainable energy. In the block a solar system will be introduced to make use of the sustainable energy available. Apart from the project in general, in the district heating system boilers are replaced by CHP. In the project the options to improve the input of sustainable in the district heating system will be discussed and elaborated.

Specific Innovations

  • An enormous energy saving performance, where normally only windows will be replaced by double glazed windows.
  • Working through home owners associations to build lending capacity and attract discounts (both in loan as in heating bills).
  • Creating cash flow by energy efficiency and creating additional apartments on the roofs of the buildings.

Staccato is a project of the concerto initiative co-funded by the European Commission under the Sixth Framework Programme