Case Study: nZEC - Energy refurbishment of 13 dwellings in Zaharna Fabrika, Sofia, Bulgaria
Name of organisation: CAC - Union of Homeowners Associations
Stage of development: completed
Year of finalization: 2012
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: 13
Tenure: shared ownership/cohousing
Street: Zaharna Fabrika bl. 11
Postcode: 1345
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 building is with individual heating provided by electrical appliances. The hot water is provided by electrical boilers.
The project includes 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, 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 52%. The achieved reduction in greenhouse gas emissions is 62 t/y.
Key Elements
Certification
Energy certificate.
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
Energy efficiency measure | Ir | Iee,brutto [€] | Iee,netto [€] | Life time [years] |
[€] | ||||
1 Thermal insulation of external walls (100 mm), ground slab (120 mm) and roof (150 mm) |
| 74 100 | 37 050 | 30 |
2 Replacement of all windows with PVC, double glazed (old U value 2.37 W/m2K replaced with U value 1.70 W/m2K) |
| 15 600 | 3 200 | 30 |
3 Replacement of lighting installation in building common parts |
| 800 | 400 | 15 |
4 Solar thermal installation for part of dwellings |
| 8 200 | 8 200 | 20 |
Total |
| 98 700 | 48 850 |
|
Running costs (savings) |
| 3 250 | 3 250 |
|
Simple payback time (years) |
| 30 | 15 | 30 |
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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
Individual heating with electrical appliances, individual electrical boilers for hot water.
Main Results
- The achieved reduction in energy use is 52%.
- The building obtained energy certificate Class B.
- Currently, the homeowners enjoy a comfortable and healthy indoor climate.
- The market assessment shows an increased property value.
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
