Integrated approach for retrofitting of the flat roofs of the buildings at 21 block in New Belgrade, Belgrade, Serbia

Group 4:Jelena Nikolic, Laura Gagyte, Pablo Villarejo, Nikolay Enchev

COST ACTION TU1104

Training School: "Integrated approach to retrofitting existing dwellings"

Content

Problem1

Methodology2

Analysis3

Results4

Problem

Problems

in the top flats there are:

water infiltration;

heat losses during cold season;

heat gains during warm season.

ground floors are not integrated in the social life;

hot water is produced by electric boilers.

COST ACTION TU1104 Training School: "Integrated approach to retrofitting existing dwellings

Methodology

COST ACTION TU1104 Training School: "Integrated approach to retrofitting existing dwellings

Methodology

short term analysis;

long therm analysis (the buildings will be insulated, windows will be changed, air infiltration

to the buildings will be reduced, mechanical ventilation will be needed, the space for ventilation

equipment will be needed);

financing analysis;

social analysis.

CHOICES

An improved, flat roof / an additional, pitched roof

changing the primary energy source for water heating / producing

renewable electricity

If electricity is produced it can be solar panels, wind turbines, biomass

or heat pumps…

Problem - Solution

COST ACTION TU1104 Training School: "Integrated approach to retrofitting existing dwellings

Inte

gra

ted

kit

of

part

s s

yste

ms

ROOF

HEAT LOSES/GAINS

WATER LEAKEAGES

SOLAR RADIATION

FUTURE VENTILATION NEEDS

ELECTRIC WATER BOILERS

NEW USES FORGROUND FLOOR

ACTIVE SYSTEMS

IMPROVED ROOF

PV ARRAY

INCOMESSOURCES

PROs

Lower maintenance needs for

pitched roofs

Space for future technical systems

Less impact on dwellers

Smaller installation costs for a PV

array (other technologies offer smaller

returns, the pitched roof offer a substructure

for it)

Façade is not used for energy

production (less visual impact)

FIT feed in tariffs

CONs

Impact on the aspect or cultural

value of buildings

Agreement of owners needed

High upfront costs (grants and investors

needed)

Technical management needed

Analysis

Regarding the energy efficiency of the current building systems, heating is

provided by a district heating scheme and in the medium term a surge in

cooling demand is not expected.

Nevertheless, there is scope for the production of renewable electricity given

the fact that hot water is currently provided by electrical individual boilers, and

a FIT programme is in place in Belgrade

Therefore, a new pitched second roof is proposed, with PV panels attached to

it. This structure produces a shaded, ventilated space over the former roof that

will also be insulated and offer room for future ventilation system, with access

to the chimneys over the existing shafts.

COST ACTION TU1104 Training School: "Integrated approach to retrofitting existing dwellings

Results: 1st phase

COST ACTION TU1104 Training School: "Integrated approach to retrofitting existing dwellings

Results: 1st phase

COST ACTION TU1104 Training School: "Integrated approach to retrofitting existing dwellings

Results: 2nd phase

COST ACTION TU1104 Training School: "Integrated approach to retrofitting existing dwellings

Mechanical ventilation with heat recovery

Results

COST ACTION TU1104 Training School: "Integrated approach to retrofitting existing dwellings

Financial plan

The proposal described has two phases: the construction of a new, insulated roof with

PV panels; and the later implementation of a ventilation system.

In both phases there are common elements that must be installed with the agreement of

all owners: these are the roof itself and the ventilators and heat recovery units for the

ventilation systems. There are also some equipment that each owner can install when

she/he decides, as the PV panels and the ducts that provide each dwell with artificial

ventilation.

The common infrastructure’s costs should be financed mainly with public funds for

energy efficiency: Belgrade’s local government is bearing up to 70% of the cost of that

kind of projects.

Individual systems should be paid by tenants via low rate loans provided by the state.

The installation of PV panels makes it possible for them to recover the cost of the

photovoltaic system itself and also to recover the part of the costs of the common

infrastructure they have to pay for, gradually via feed-in tariff. Also, income from the rental

of ground floor spaces can be considered.

THANK YOU FOR YOUR ATTENTION!