Benefits of Refurbishment - Nearly Zero Energy Building Refurbishment - page 107

Then, it depends on the typology and efficiency of the used plants. For each
action, it is assessed on the basis of E s,y and of the reference emission factor of
each electricity mix and national gas-fired heating plants.

E R was defined as follows:

E R ¼ E s = GER ð 3 Þ

where E s is the total saving of primary energy during the lifetime of each retrofit
action (GJ).

3.2 Results

3.2.1 Case Study: Brno

The retrofit of the Brewery building (Brno) included the following actions:

• refurbishment of the building envelope with new thermal insulation and high-
efficiency windows to reduce the thermal losses and the lighting need,
• installation of PV panels and of high-efficiency technology for heating and
ventilation.

Figure 1 compares GER to total energy saving, while Fig. 2 shows the con-
tribution to GER of each retrofit phase. The construction phase required the use of
electricity and diesel oil to operate the machinery. The disposal scenario included
the transportation of wastes coming from the building site and their disposal to
local landfills. It is observed that the highest GER is due to the PV plants, while
insulation and window replacement represent 4 % and 3 % of GER, respectively.
The construction phase represents 19 % of GER, while the contribution due to
wastes disposal is 4 % of GER. The retrofit of the building envelope provides
yearly primary energy savings of 586 GJ/y. In particular, the building insulation
that was improved with mineral wool boards of 100 mm for the facade and the

Fig. 1 GER compared to the
total energy saving in Brno
case study (brewery)

Case study: Brno

25,000

PV
Building
insulation

Low-e windows
HVAC system

20,000

15,000

10,000

5,000

0

0 200 400 600 800 1000

GER [GJ]