Municipal Administration of Berk
nZEB Example

Major renovation to energy class A

The building has been fully renovated and thermal insulation materials have been laid on all solid surfaces: walls, floors and roofs. Internal insulation has been used for some of the walls and roofs. All the original windows and doors have also been replaced and this has happened gradually over the years. The heating system has been replaced by one with variable refrigerant flow (VRF) systems with very good performance characteristics and a seasonal transformation efficiency SCOP>3,5W/W, which is considered as RES under Bulgarian legislation.

Building owner

Berkovitsa Municipality

Building type
Project type
Year of construction / major renovation

Construction: 1971
Major renovation: Yes

Total floor area
3176 m²
Construction U-value
nZEB Parameters

Total annual energy consumption – 108,51 MWh/a or 34,2 kWh/m2/a
Primary energy consumption – 102,5 kWh/m2/a or 101,8 kWh/m2/a
Building air tightness – n=0,50 h-1
CO2 emissions – 70,4 tco2/a
Renewable share of energy – 49% of the energy needs for Heating, Cooling, Ventilation, DHW and Lighting; equating to 100,3 MWh per year

Scroll to Top