REFURBISHMENT OF RESIDENTIAL BUILDINGS ACCORDING TO THE SERBIAN POLICY A CASE STUDY IN BELGRADE Vladimir Jovanovic, M.Arch, PhD student at Institute for Architecture and Design, TU Wien Karin Stieldorf, Ass. Prof. at Institute for Architecture and Design, TU Wien

1. REFURBISHMENT OF RESIDENTIAL BUILDINGS
ACCORDING TO THE SERBIAN POLICY
A CASE STUDY IN BELGRADE
13-14th February 2014
Vladimir Jovanovic, M.Arch, PhD student at Institute for Architecture and Design, TU Wien
Karin Stieldorf, Ass. Prof. at Institute for Architecture and Design, TU Wien
Wiener Kongress für
zukunftsfähiges Bauen

2. Outline
1) Introduction
2) State-of-the-art regulations
3) Policy-driven refurbishment
4) Results
5) Conclusion
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic

3. Motivation
Serbia
building industry
efficiency
EU-Partner
investments
Market
7.2 m.
Austria investor no.1
3.1 b. $, 400 firms
Source: National Tourism Organisation of Serbia
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic

4. Introduction
35% energy - households
(SEA, 2012)
220 kWh/m2a
Heating, HWP
70% population - houses
Regulations
2010; 2011; 2013; 2014…
Clarification
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic

5. Goal
 evaluate policy-driven refurbishments
 environmental, economical and social
assessment
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic

6. Climate in Belgrade (SRB)
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic

7. Catalogue of typical house designs
from 1970’s and 1980’s
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic
Source:
Catalogue of typical
house designs “Nas stan”
Houses 70% (dense?)
43% of housing 1970 – 1990
NEEAP: 1970’s and 1980’s

8. Simulation model
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic
Component Surface Thickness U-value
Floor 63 m2 56.6 cm 1.52 W/m2k
Ex. walls 206.7 m2 22 cm 0.8 W/m2k
Roof ceil. 63 m2 21.5 cm 0.89 W/m2k
Windows 23.12 m2 6-16-6 mm 2.91 W/m2k
 Euro-WAEBED simulation software
 GEBA simulation software
q=145 kWh/m2a
Concrete-skeleton structure, concrete foundations.
Semi-fabricated ceiling construction.
External walls: brick-blocks and plaster finishing.
Roof: timber-frame construction, clay roof tiles.
Double glazed windows.
No thermal insulation.

9. Driven by current and incoming policy
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic
Scenario According to Target
Initial - -
R1 (2011) Rulebook EEB Boundary U-values
R2 (2010) 1st NEEAP Reduce for 50 kWh/m2a
R3 (exp. 2014) 2nd NEEAP estimation Reduce to 75 kWh/m2a
R4 (Future) Passive house standard PH retrofit

10. 2011 Rulebook on Energy Efficiency in Buildings
Pravilnik o energetskoj efikasnosti zgrada (Sluzbeni glasnik RS, br.61/2011)
Building element Refurbishment
Umax [W/m2K]
New
Umax [W/m2K]
External walls 0.40 0.30
Inner elements, heating zones 0.90 0.90
Flat roof, heated area 0.20 0.15
Flat roof, non-heated zone 0.40 0.30
Pitched roof, non-heated zone 0.40 0.30
Windows and glazed elements 1.50 1.50
Entrance doors 1.60 1.60
Ceiling construction, non-heated zone 0.40 0.30
Wall in the ground 0.50 0.35
Floor on the ground 0.40 0.30
R1 Rulebook R2 1st NEEAP R3 2nd NEEAP est. R4 PH standard

11. 2011 Rulebook on Energy Efficiency in Buildings
Pravilnik o energetskoj efikasnosti zgrada (Sluzbeni glasnik RS, br.61/2011)
External walls Roof ceiling construction
External plaster 1.5 cm Cement screed 4 cm
Brick-blocks19 cm Insulation layer 6 cm
Insulation layer 6 cm Concrete 4 cm
Internal plaster 1.5 cm Ceiling structure “Monta” 16 cm
Internal plaster 1.5 cm
Uwall=0.37 W/m2K Uceiling=0.37 W/m2K
R1 Rulebook R2 1st NEEAP R3 2nd NEEAP est. R4 PH standard

12. 1st NEEAP for the period 2009-2018
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic
First Serbian Energy Efficiency Action Plan
“The target of 9% of energy savings by 2018 in
residential sector could be achieved if buildings reduce
the heating demands for at least 50 kWh/m2a”
R1 Rulebook R2 1st NEEAP R3 2nd NEEAP est. R4 PH standard

13. 1st NEEAP for the period 2009-2018
External walls Roof ceiling construction
External plaster 1.5 cm Cement screed 4 cm
Brick-blocks19 cm Insulation layer 8 cm
Insulation layer 8 cm Concrete 4 cm
Internal plaster 1.5 cm Ceiling structure “Monta” 16 cm
Internal plaster 1.5 cm
Uwall=0.31 W/m2K Uceiling=0.32 W/m2K
R1 Rulebook R2 1st NEEAP R3 2nd NEEAP est. R4 PH standard

14. 2nd NEEAP estimation from 2013 (expected 2014)
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic
Batas Bjelic et al. (2013)
Policy driven refurbishment from Second Serbian NEEAP
in accordance to the EPBD directive 2010/31/EC could
encompass a reduction of heating demands for
refurbished buildings to 75 kWh/m2a.
R1 Rulebook R2 1st NEEAP R3 2nd NEEAP est. R4 PH standard

15. 2nd NEEAP estimation from 2013 (expected 2014)
External walls Roof ceiling Windows and doors
External plaster 1.5 cm Cement screed 4 cm Double glazing
Brick-blocks19 cm Insulation layer 10 cm 6-12-6 mm (Kr)
Insulation layer 10 cm Concrete 4 cm External shutters
Internal plaster 1.5 cm Ceiling structure “Monta” 16 cm
Internal plaster 1.5 cm
Uwall=0.27 W/m2K Uceiling=0.27 W/m2K
Uframes=1.1W/m2K
Udoor=1.8W/m2K
R1 Rulebook R2 1st NEEAP R3 2nd NEEAP est. R4 PH standard

16. Passive house refurbishment
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic
National PH definition: 15 kWh/m2a
Energy Certification of Buildings
A+ grade: 15 kWh/m2a
Source: Pravilnik o uslovima, sadrzini i nacinu izdavanja sertifikata o
energetskim svojstvima zgrada (Sluzbeni glasnik RS 69/2012)
R1 Rulebook R2 1st NEEAP R3 2nd NEEAP est. R4 PH standard

17. Passive house refurbishment
External walls Roof ceiling Roof skin Floor Win./doors Ventilation
Ex. plaster 1.5 cm Cement screed 4 cm Roof tiles on laths Parquet 2.4 cm Double glazing Heat-recovery
efficiency rate 75%
Brick-blocks19 cm Insulation 25 cm Osb boards Cement screed 4 cm 6-12-6 mm (Kr) Air-to-air exchanger
Insulation 25 cm Concrete 4 cm Rafters Insulation 10 cm External shutters Air-tightness 0.5 m2h-1
In. plaster 1.5 cm Ceiling structure
“Monta” 16 cm
Ins. 14 cm Concrete 10 + 8 cm
Internal plaster 1.5 cm Gyps-plaster
boards
Gravel 20 cm
Uframes=1.1W/m2K
Uwall=0.13 W/(m2K) Uceiling=0.13 W/(m2K) Uroof=0.3 W/(m2K) Ufloor=0.32 W/(m2K) Udoor=1.8W/m2K
R1 Rulebook R2 1st NEEAP R3 2nd NEEAP est. R4 PH standard

18. The designed
refurbishments met
target set.
Scenario Target Result
Initial - q=145 kWh/m2a
R1 Boundary
U-values
 Uwall, Uceiling
=0.37 W/m2K
R2 Reduce for
50 kWh/m2a
 Reduced for
54 kWh/m2a
R3 Reduce to
75 kWh/m2a
 Reduce to
69 kWh/m2a
R4 PH  PH achieved
Figure 2. Reduced heating demands in kWh/m2a
Results : Environmental impact

19. R1 and R2 - small
decrease of temperatures
R3 - temperatures
decreased for about 2°C
R4 - additional cooling
Results : Overheating potential
Figure 3. Temperatures in south-oriented living room for the mid of July

20. Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic
R1 and R2 - the most affordable
R3 better investment-return than
R4 (the highest investment)
Average price of gas, wood and
electricity: 4.9 cent/kWh
Long pay off period -relatively
low current energy price
Scenario Total
invest.
Investment
per m2
Savings in 30
years
Payoff
Initial - - - -
R1 4200 € 33 €/m2 177 MWh 15 years
R2 5000 € 40 €/m2 204 MWh 15 years
R3 8800 € 70 €/m2 278 MWh 20 years
R4 28300 € 225 €/m2 491 MWh 35 years
Results : Economical assessment

21. Conclusion
Defined and evaluated specific measures - single house - policy EEB
Sampling procedure - number of similar houses
Recommendation: SEED - appropriate retrofit for particular house
Clarification of the policy, understanding SEE-benefits
- encourage tenants, increase of retrofit rates in Serbia
Refurbishment of Residential Buildings According to the Serbian Policy Vladimir Jovanovic

22. References
1) Serbian Energy Agency, Annual Report 2012, Belgrade, 2013.
2) Todorovic, M., First NEEAP/BS national energy efficiency action
plan/building sector 2009-2018. u: Study Report and NEEAP-BS
for the Republic of Serbia Ministry of Mining and Energy,
Washington: IRG, June 2010.
3) Pravilnik o energetskoj efikasnosti zgrada(Sluzbeni glasnik RS,
br.61/2011)
4) I. Batas Bjelic, N. Rajakovic, R.Elsland, W. Eichhammer,
Improvements of Serbian-NEEAP Based on Analysis of Residential
Energy Demand until 2030, Proceedings, 8th IEWT conference,
Vienna, Austria, February 2013.
5) Z. Mihailovic, Catalog of typical house designs, Organization for
architectural design “Nasstan”, Belgrade 1979.
6) Statistical office of RS, http://www.stat.gov.rs (01.04.13).
Acknowledgments
The study is a part of the PhD thesis
“Patterns for Energy Efficient Design in Serbia”
financially supported by the
Alfred Toepfer Stiftung F.V.S. Hamburg

23. Vladimir Jovanovic, M.Arch.
Institute for Architecture and Design, TU Wien
jovanovic.vlad@yahoo.com
REFURBISHMENT OF RESIDENTIAL BUILDINGSACCORDING TO THE
SERBIAN POLICY
Thank you for your attention.
February 2014
Vienna Congress on
Sustainable Building