The Sustainability of a Building Made by using of Recycling Materials
TUDORICA M.1, GHEMIS M.- T.1, BOB C.2
1Department of Civil Engineering, University of Oradea, Faculty of Civil Engineering,
Cadastre and Architecture, Barbu Stefanescu Delavrancea Street, No.4, Oradea,
ROMANIA
2Department of Civil Engineering, ''Polytechnic'' University of Timisoara,
Faculty of Civil Engineering,Traian Lalescu Street No.2, Timisoara,
ROMANIA
Abstract: A very important problem encountered all over the world and increasingly widespread in the
construction field is represented by sustainability. This paper presents a sustainability study, performed on a
building located in Romania - Arad County, which involved the consolidation and expansion of an existing
building in order to create an investment with the functionality of an agrotourism guesthouse. The sustainability
study involved the calculation of coefficients of the environmental dimension on the basis of which the
embodied energy and green house gas emissions GHG were estimated as a result of the selected materials,
transportation and equipment used during the process. The social dimension was taken into account by
establishing the coefficients that influence visual, acoustic and thermal comfort. Besides the fact that modern
construction resulted from the perspective of the materials and equipment used, an important factor represents
that, part of the materials that resulted from the partial demolition of the existing construction, were reused.
Key-Words: sustainability, embodied energy, consolidation, existing building, environmental, economic
dimension, social criteria, demolition, reused materials
Received: June 5, 2022. Revised: November 9, 2022. Accepted: December 11, 2022. Published: December 31, 2022.
1 Introduction
In the broadest sense, sustainability means the
ability to maintain or support a process continuously
over time. In time this notion has become more and
more complex, [1].
The most agreed definition is "Sustainable
development is development that meets the needs of
the present without compromising the ability of
future generations to meet their own needs", [2].
Sustainable development has been identified as a
top priority problem in construction works.
Directives and standards have been developed
which are intended to encourage the implementation
of sustainable criteria in the life cycle stages of a
construction work, [3].
This notion is often broken into three core
concepts: environmental protection, social and
economic development.
On the other hand, ensuring environmental
sustainability is a noble task that civil engineers
should pursue, both when preserving or refurbishing
structures and designing tomorrow's infrastructure.
What engineers design and built today will
influence the environment and society for decades
to come, [4].
The buildings and buildings construction sectors
combined are responsible for almost one-third of
total global final energy consumption and nearly
15% of direct CO2 emissions. As seen in Figure.1,
direct and indirect emissions from building
operations, [5], plummeted to about 9 Gt in 2020,
after having risen an average 1% per year since
2010.
Fig. 1: Global CO2 emissions from building in the
Net Zero Scenarios 2010-2030
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The EU aims to be climate-neutral by 2050 - an
economy with net-zero greenhouse gas emissions,
[6]. Despite the expected rebound in emissions in
2021 being moderated by continued power sector
decarbonisation, buildings remain off track to
achieve carbon neutrality by 2050. To meet this
target, all new buildings and 20% of the existing
building stock would need to be zero-carbon-ready
as soon as 2030, [7].
2 Sustainability Model
Worldwide, there are more sustainability models.
The most well-known are presented in Figure 2, [8].
Fig. 2: Sustainability Assessment Methods
Average values of sustainability assessment
methods :
64,0
med
e
;
18,0
med
s
;
cmed 15,0
Average values without including BREAAM
and LEED criteria:
46,0
1
med
e
;
28,0
1
med
s
;
27,0
1
med
c
For the sustainability study, the authors used
Bob-Dencsak model. This model is based on 44
parameters, out of which 21 correspond to the
environmental dimension, 11 to the economic
dimension and 12 to the social dimension.
According to this model for a sustainability index
obtained by calculus greater than 4 (80 points) the
level of sustainability is very good, for an index
between 3 and 4 (60-80 points) is good, for 2-3 (40-
60 points) acceptable and for less than 2 (40 points)
is insufficient.
The parameters are explained for each criterion
as follows:
The environmental criteria
Initial embodied energy (En1) depends on the
embodied energy (EE) in terms of manufacturing
the materials, their transport and the equipment or
machines used in the construction process.
(1)
Non-renewable embodied energy during the life
cycle of the building (En2) was calculated in the
energy performance certificate according to the
annual energy consumption.
Non-renewable embodied energy in construction
materials used for maintenance, renovation and
replacement works (En3) and the embodied non-
renewable energy in building materials after the end
of life (En4), [9], are calculated with Formula (1) for
the related works.
En5 is estimated depending on the use of
renewable energy sources.
Initial green house gas GHG emissions (G1) are
calculated in a similar way as the initial embodied
energy, with the difference that the input data, in
this case, are the CO2,eq emissions in the
manufacturing of the materials, transportation and
use of equipment or machines, [10], during the
construction process.
tA
m
G
CO eq 2
1
(2)
GHG emissions during the life-cycle of the
building (G2) were calculated in the energy
performance certificate according to the CO2
equivalent emission index.
GHG emissions from construction materials used
for maintenance, renovation and replacement works
(G3) and end of life GHG emissions (G4) are
calculated with Formula (2) for the related works.
Heat island effect of the roof (G5) is calculated
using the Solar Reflectance Index (RIi) of roofing
material and the roof surface (Ai)
i
i
n
A
A
RI RIi
(3)
The efficiency of the materials used according to
the building design is given by the following
parameters:
Re-use of existing materials, products and
structural elements (MR1) it is expressed by the ratio
between the reused structural area and the total area.
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Material efficiency (MR2) is the total weight of
the structure (G) per the entire volume (V) of the
building.
V
G
MR
2
(4)
Use of materials with recycled content (MR3) it
is expressed by the ratio between the weight of
recycled materials and the total weight.
Use of local resources (MR4) is a parameter
depending on the transport distance (di) of the
materials mti.
m
dm
MR iti
4
(5)
In our case, the effects of the works on the
construction site are reflected through the waste
from the construction site (CS1), the dust produced
on the construction and demolition process stored
outside the construction site (CS2) which is
estimated from the protection measures provided in
the project and the noises generated in the
construction process (CS3).
d
isi
h
hL
CS
3
(6)
where:
Lsi - level of sound produced by the equipment
hi - hours in use of the equipment/machine
hd - daily number of working hours
Last environmental parameters are for the soil
contamination by execution (LW1), the land used
(LW2) which is the ratio between the built area and
the land surface, and water consumption (LW3).
Water consumption depends on the number of
people staying at the guesthouse.
The economic criteria
The initial cost C1 represents the ratio between
the total cost of the construction (including all costs
related to the design such as structure, labor cost,
technical assistance, approvals etc.) and the useful
surface of the building.
Operational cost C2 represents the annual cost for
the building’s utilities divided by the unit of surface.
The cost of maintenance and renovation C3
represents the ratio between the cost of the
respective works and the useful area of the building.
Time of construction CP1 is calculated as the
ratio between the total number of workers
multiplied by the number of hours (W) per surface
unit.
A
W
CP1
(7)
The production rate CP2 calculated with the
formula:
1
21
2 CP
CC
CP
(8)
Construction schedule CP3 is given by the
smoothing factor Ca:
max
a C RD
W
(9)
where:
D - total time for the construction of the building
Rmax - maximum number of workers on site, at
the same time
Life cycle efficiency Ef1 represents the life cycle
of the building without being necessary major
renovation or rehabilitation of the structure.
Area efficiency Ef2 is the efficient use of the
space, calculated as a ratio between the useful area
(An) and the entire built area (A).
A
A
Ef n
2
(10)
The social criteria
Cf1 is estimated depending of the degree of
thermal comfort throughout the year, both in
summer and in winter
Noise and acoustic comfort Cf2 is given by the
airborne sound insulation Dn,t and by the impact
sound insulation Ln,w:
Airborne sound insulation:
)lg(10 0
,S
A
RD tn
(11)
where:
R - sound reduction index
A0 - reference area 10 sqm
S - total surface of the rooms
)
1
lg(10 T
R
(12)
where:
T - sound transmission coefficient
mfn
c
T
0
(13)
where:
c
0
= acoustic impedance
n - number of surface parts
f - frequency
m - mass/unit area of the partition
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The average transmission coefficient for composite
partitions is:
n
iiiav ATAT
1
(14)
where:
A - total area of partition
Ti - transmission coefficient for surface part i
Ai - area of surface part i.
Impact sound insulation represents the insulation for
noise generated in the building by: footsteps,
general repairs, moving furniture etc.
weqnwwn LLL ,,
(15)
mL eqnw lg35164
,
(16)
where:
Lnw,eq - level of sound pressure caused by
footsteps on the finished floor slab
Lw - level of sound pressure caused by footsteps
on the floor slab without finishes.
m - the mass of the slab/unit of surface.
To determine the visual comfort Cf3 we calculate
the average daylight factor ADF using the equation:
)1( 2
RA
TAM
ADF w
(17)
where:
Aw - total area of windows or skylights
M - correction factor
- angle of visible sky
T - glass transmission factor
R - area weighted average reflectance of the
room’ surfaces.
A - total area of room’ surfaces
The quality of the indoor air is measured by three
factors: the concentration of volatile organic
compounds in the indoor air IAQ1, CO
concentration in the indoor air IAQ2 and the
effectiveness of ventilation in naturally or
mechanically ventilated spaces IAQ3
The safety of the construction is evaluated by
establishing the degree of flood protection (Sa1), fire
protection (Sa2) and earthquake protection (Sa3).
The accessibility and the adaptability of the
building it's characterized by coefficients that take
into account: the time needed to reach the public
transport system (AA1), criteria such as: parking,
elevator, WC, maneuverability (AA2), the
adaptability of the structure to new opportunities
such as changing the structural system (AA3), and
finally adaptability to new energy sources (AA4).
3 Case Study
The subject of the sustainability study is an agro-
tourism guesthouse which was constructed with
European funds, finished at the beginning of 2020.
The payment stages were made after the
performance evaluation. The investment reached the
amount of 245,000 EURO, out of which 73,000
EURO represents expenses for the arrangement of
the exterior spaces, furnishing and equipping the
interior spaces that are not included in the actual
study.
Even if the consolidation solutions are not the
subject of this article, [11], an important factor is
represented by the reuse of 45 cubic meters of brick
resulting from the demolition of the old building.
It is an efficient and modern construction in
terms of equipment, where we refer to the 32-37 kW
ground-water heat pump, with a water outlet
temperature of 35-60 Celsius degrees, as well as the
replacement of the classic system with radiators
with fan coils which in addition to comfort, it also
ensures the ventilation of the rooms in all 12 months
of the year. The volume of the construction is
1544.98 cubic meters and the useful surface on both
2 levels is 485.93 square meters. The footprint is
297 square meters, located on a plot of 1086 square
meters. The building was designed for a life cycle of
75 years (t = 75 years).
The energy performance certificate was made by
the company Certific Ro, where resulted from a
high energy efficient building - class A with an
annual energy consumption of 54.84 kWh/m2/year
and a CO2 equivalent emission index of 33.96
kgC02/m2/year. The values used in the sustainability
study for energy consumption are detailed in Table
1, [12], and the values of sustainability parameters
obtained by the authors are shown in Table 2.
Table 1. Specific annual energy consumption
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Table 2. Values of sustainability parameters
Parameter name
Benchmark
Calculated
or
estimated
value
Point
score
wi
Weight
factor
pi
%
pi*wi
points
wi min
wi opt
20
points
100
points
En1 (MJ/sqm/y) Initial embodied
non-renewable energy in original
construction materials
180,00
60,00
71,96
92,03
2,50
2,30
En2. (MJ/sqm/y) Non-renewable
embodied energy in all facilities of
building operation (HVAC)
1.100.00
450.00
197,43
100,00
6,50
6,50
En3. (MJ/sqm/y) Non-renewable
embodied energy in construction
materials used for maintenance,
renovation and replacement works
40.00
15,00
12,59
100,00
2,00
2,00
En4. (MJ/sqm/y) Embodied non-
renewable energy in building
materials after end of life
35.00
10.00
12,67
91,71
1,00
0,92
En5. (%) Use of renewable energy
sources
0.00
25.00
57,21
100,00
2,00
2,00
G1. (kg CO2eq/sqm/y) Initial GHG
emissions
20.00
6.00
7,14
93,49
2,00
1,87
G2. (kg CO2eq/sqm/y) GHG
emissions from all facilities in the
building operation (HVAC)
93.00
10.00
33,96
76,91
4,00
3,08
G3. (kg CO2) GHG emissions from
construction materials used for
maintenance. renovation and
replacement
3.00
1.00
0,84
100,00
1,00
1,00
G4. (kg CO2) End of life GHG
emissions
1.90
0.60
1,05
48,57
1,00
0,49
G5. (%) Heat island effect of the roof
29.00
95.00
89,00
92,73
1,00
0,93
MR1. (%) Re-use of existing
materials, products and structural
elements, if available
0.00
50.00
24,00
58,40
1,00
0,58
MR2. ( kg/m3) material efficiency
2.000.00
900.00
1045,35
89,45
2,00
1,79
MR3. (%) Use of materials with
recycled content
0.00
30.00
4,43
18,85
2,00
0,38
MR4. (km) Use of local resources
60.00
5.00
17,55
81,75
1,00
0,82
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CS1. (%) Waste from construction
and demolition process sent off the
site
5.00
50.00
-
10,00
2,00
0,20
CS2 (%) Dust produced during
construction
20.00
100.00
-
70,00
1,00
0,70
CS3. (%) Noise produced during
construction
105.00
70.00
87,32
60,41
1,00
0,60
LW1. Construction on contaminated
land
Yes
No
No
100,00
2,00
2,00
LW2. (%) Ground occupancy
percentage
>30
30.00
25,43
100,00
2,00
2,00
LW3. (l/p/d) Potable water
consumption by building occupants
180.00
90.00
-
80,00
2,00
1,60
LW4. (%) Use of grey and rain
water
0.00
30.00
0.00
20,00
1,00
0,20
TOTAL ENVIRONMENTAL CRITERIA - e
31,95
C1. (euro/sqm) Initial cost
650.00
300.00
354,00
78,66
5,00
3,93
C2. (euro/sqm/y) Operational cost
40.00
5.00
4,73
100,00
5,00
5,00
C3. (euro/sqm/y) Maintenance and
Repair Cost
25.00
5.00
7,20
91,20
3,00
2,74
CP1. (man x h/sqm) Total time for
the construction of the building
120.00
55.00
55,58
99,29
2,50
2,48
CP2. (euro/h) Production rate
6.00
15.00
12,74
100,00
2,50
2,50
CP3. – Ca Construction Schedules
0.40
0.90
0,87
95,20
1,00
0,95
PM1. (no. of documents) Initial
documents
3.00
10.00
10,00
100,00
2,00
2,00
PM2. (no. of documents) Documents
of maintenance and operation
0.00
Yes
Yes
100,00
2,00
2,00
PM3. Monitoring of performances
0.00
Yes
Yes
100,00
2,00
2,00
Ef1. y Long service life
25.00
75.00
75.00
100,00
3,00
3,00
Ef2. (%) Area efficiency
70.00
95.00
82,00
58,40
2,00
1,17
TOTAL ECONOMICAL CRITERIA - c
27,77
Cf1. PPD, PMV Thermal Comfort
<15
<6
-
90,00
4,00
3,60
Cf2. Noise and acoustic Comfort
35,00
47,00
50,43
58,71
1,50
0,88
70,00
58,00
77,30
Cf3. (%)Visual Comfort
0.50
3.00
2,07
70,24
1,50
1,05
IAQ1. (%)VOC concentration in
indoor air
0.30
0.80
0.80
100,00
1,00
1,00
IAQ2. CO concentration in indoor air
Yes
No
No
100,00
2,00
2,00
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The quantification of results was made also
using Bob-Dencsak model. The score obtained for
each parameter was achieved by interpolating the
value between the minimum and the optimum
benchmark.
The sustainability index is the sum
ii wp
of
all three criteria:
3,03,04,0 sceBSI
(18)
where:
875,79
4.0
ee
ii
wp
e
90,90
3.0
cc
ii
wp
c
10,95
3.0
ss
ii
wp
s
GOODVERYBSI 75,87
The graphical result of the parameters e, c and s
are presented in Figure 3, where the triangle
represents the sustainability index, [13].
Fig. 3: The graphic result of BSI
4 Conclusion
The result of the study is a building with a very high
level of sustainability, obtaining a sustainability
index of 87,75.
It is observed that the environmental dimension
has the lowest value, very close to a very good level.
The fact that quality materials were used increased
this score, but especially the reuse of the materials
resulting from the demolition of the old building, as
well as equipping the building with a ground-water
heat pump and fan coil units. These led to low
energy consumption and CO2 emissions during the
construction process, but especially during the
exploitation process which seems to have the largest
ratio.
IAQ3. Effectiveness of ventilation in
natural or mechanical ventilated
spaces
0.30
0.80
0.80
100,00
1,00
1,00
Sa1. Protection against earthquake
RsI
RsIV
RsIV
100,00
7,00
7,00
Sa2. - (mm) Protection against flood
1.000.00
6.000.00
6.000.00
100,00
4,00
4,00
Sa3 – Protection against fire
5.00
1.00
1.00
100,00
3,00
3,00
AA1. (Min) Access to public
transport systems and proximity to
user specific facilities
30/50.
5/10.
5/10.
100,00
1,50
1,50
AA2. Lifetime homes
30.00
5.00
5.00
100,00
1,50
1,50
AA3. Adaptability constraints
imposed by structure
No
Yes
Yes
100,00
1,00
1,00
AA4. Adaptability to future changes
in type of energy supply
No
Yes
Yes
100,00
1,00
1,00
TOTAL SOCIAL CRITERIA - s
28,53
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A very important aspect of the economic
dimension is the documentation, efficiency and
follow-up of the construction, which has a ratio of
11% of the final result. If they are done responsibly
a significant savings percentage is made on the cost
of materials and labor. In this sense, a score of 90.90
points was achieved.
The social dimension obtained the highest score
which is 95 points, being an investment in a
developed area of the county, these aspects being
taken into account from the beginning.
The results were obtained after analyzing a large
number of factors, which allow us to identify the
strong points, but also the weak points of the study.
Thus we can say that the sustainability study in
the design stage could help us choose better
solutions (other types of material, more efficient
equipment, location) that would result in a building
with a higher sustainability level.
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