Case Study: nZEC - Energy refurbishment of 18 dwellings in Tzar Samuil Street, Sofia, Bulgaria
Name of organisation: CAC - Union of Homeowners Associations
Stage of development: completed
Year of finalization: 2011
Type of project: refurbishment
Area: urban
Scale: individual buildings
Type of building: Apartment in a block of five or less stories
Number of units/dwellings: 18
Tenure: shared ownership/cohousing
Street: 2 Tzar Samuil Str.
Postcode: 1463
City: Sofia
Region/ County: Sofia City Province
Country: Bulgaria
Last Update: 03.03.2015
Short Description
The project was carried out because of the high price for heating and the uncomfortable indoor climate. The project was implemented within the framework of the National Renovation Program with a 75% of subsidy on the renovation costs. The building construction type is brickwork on concrete skeleton. The heating of the building is district heating hot water type with water temperature 140/70 degree С. There is a heat exchanger located in the basement.
The investment project for building energy renovation comprehends a complete refurbishment of the building envelope – thermal insulation of the external walls, the roof, the ground slab and replacement of the window frames with PVC double glazing. The project also includes renovation of the common areas – staircases, building installations, heat exchanger, etc. The decrease in the energy consumption for heating is achieved by: decrease of thermal transmittance (U value) coefficient of the external walls; decrease of thermal transmittance (U value) coefficient of the roof; decrease of thermal transmittance (U value) coefficient of the building ground slab; decrease of thermal transmittance (U value) coefficient and the infiltration of the windows and the doors. The achieved reduction in energy use is 51%. The achieved reduction in greenhouse gas emissions is 38 t/y.
Key Elements
Certification
Energy certificate. Energy auditing by a licensed private company selected on the basis of a public bid.
Project Management
Monitoring service quality.
Work with Residents
Support and advice for homeowners during the project preparation phase and the approval of the investment needed for the planned energy renovation measures; support and advice for homeowners during the project implementation phase; advice for homeowners on the subsequent management and maintenance phase.
Funding
Splitting renovation costs with residents.
Solar Thermal
Thermal insulation system for the building envelope – external walls, roof, ground slab; replacement of the existing window frames with PVC double glazing window frames; replacement of the lighting system.
Heating and Hot Water
District heating with hot water.
Main Results
Increased comfort of the living environment with higher quality of indoor climate at the same pre-renovation annual energy expenditure. Increased value of the apartments. Protected building structure without thermal bridges.
Lessons learned
Need to raise the awareness of homeowners through trainings and information campaigns before taking any actions for energy renovation of multi-story apartment buildings in order to make informed decisions on the type of measures needed.
Additional Information
Ms Eleonora Gaydarova
CAC - The Bulgarian Union of Homeowners Associations
E-mail: cac@mail.orbitel.bg
Web: www.cac-bg.org