Ensuring Sustainability of Residential Buildings by using Local

Materials in the Conditions of the Republic of Moldova

DOINA-CEZARA ALBU, ION SERBANOIU

Department of Concrete, Materials, Technology and Management,

Technical University „Gheorghe Asachi” of Iasi,

Prof. Dimitrie Mangeron av. 1, RO-700050 Iasi,

ROMANIA

Abstract: - The study is an overview of the current situation in the Republic of Moldova regarding the

sustainability of residential buildings. Advances in the building industry indicate a shift towards energy

efficiency with minimal consumption. The authors aim to find a sustainable solution for implementation in the

Republic of Moldova. To achieve this, they perform energy efficiency calculations for the envelope of a

residential building that utilizes locally available limestone blocks, sourced from 44 quarries across the

territory. Technical abbreviations will be defined upon their first use. For thermal insulation, the authors

suggest using two layers of masonry enclosing 6 cm thick polyurethane foam. The purpose of this study is to

highlight the importance of sustainability in the construction of new residential buildings in the Republic of

Moldova. This is particularly relevant in the absence of a comprehensive regulatory framework on energy

efficiency for residential buildings.

Key-Words: - sustainability, limestone blocks, energy efficiency, sustainable material, building solution,

thermal insulation.

Received: April 29, 2022. Revised: November 17, 2023. Accepted: December 15, 2023. Published: January 18, 2024.

1 Introduction

The study of sustainable buildings has become

increasingly significant since the 20th century, due

to concerns regarding the adverse impacts of the

construction industry on the environment and

human welfare. In the Republic of Moldova,

research has been carried out over the last two

decades.

Research into building sustainability centers on

several critical areas to develop groundbreaking

solutions and technologies aimed at decreasing

detrimental environmental effects and enhancing the

energy efficiency of buildings (Figure 1).

Fig. 1: Research areas into building sustainability

Energy efficiency research aims to develop

technologies and systems that reduce energy

consumption in buildings. This field of study has

existed since the 1970s, and numerous international

researchers have explored this subject, [1], [2], [3].

In Moldova, research on energy efficiency in

buildings has only been conducted for the past

decade, [4], [5], [6], [7].

The incorporation of environmentally-friendly

and sustainable building materials plays a

substantial role in reducing environmental impact

and enhancing longevity in the construction

industry. It is vital to consider sustainable materials

and their usage when constructing buildings,

structures, and infrastructures. Recent studies have

emphasized the development of recyclable and

renewable materials to further boost energy

conservation since the 2000s, [8], [9], [10], [11],

[12]. Until the 2000s, load-bearing structures of

residential houses in the Republic of Moldova were

constructed using environmentally friendly

materials such as limestone blocks and mudbrick.

This change in construction materials has had a

significant impact on the housing industry in

Moldova. However, after the 2000s, there was a

shift towards reinforced concrete skeleton-type

Energy

efficiency

Use of

sustainable

materials

Resource

efficiency

Indoor air

quality

Social and

economic

impact

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DOI: 10.37394/232015.2024.20.7

Doina-Cezara Albu, Ion Serbanoiu

E-ISSN: 2224-3496

Volume 20, 2024

resistance systems with brick infill walls, and later

AAC, [13], [14].

Resource efficiency aims to decrease water

usage in construction and improve water

management practices. Furthermore, there is an

exploration of methods to minimize waste generated

throughout the construction and operation of

buildings, [15], [16], [17]. This area of building

sustainability in the Republic of Moldova has not

been researched.

Indoor air quality research has been working

towards enhancing indoor air standards by

decreasing the emission of volatile chemicals and

optimizing ventilation since the 1980s, [18], [19],

[20].

The social and economic impacts of these

efforts are important considerations. Studies

examine the social and economic impacts of

sustainable buildings, including concerns about

quality of life, occupant health, and the economic

benefits of sustainable architecture, [21], [22], [23],

[24], [25].

Introducing innovative solutions and

technologies through continuous research and

innovation is essential to lay the foundations for a

more sustainable future. For Moldova, achieving

sustainability in the construction sector remains an

unexplored terrain.

The study will focus on the use of sustainable

local materials for the construction of residential

buildings with the goal of near-zero energy

consumption.

2 Problem Formulation

The energy efficiency of Moldovan residential

buildings has been addressed in the past decade.

Currently, the Energy Efficiency Agency and the

Government of the Republic of Moldova are

collaborating on a project to establish and maintain

a national information system on the energy

performance of buildings. This initiative aims to

implement the strategy for upgrading the country's

building stock and the national plan to increase the

number of buildings with near-zero energy usage.

Through this legislative initiative, the government

emphasizes its growing interest in reducing final

energy consumption, as buildings account for

approximately 50% of total consumption.

Analyzing the construction sector in the

Republic of Moldova over the past five years on a

territorial level (Figure 2), a significant development

can be observed in the central area, where the

capital is located.

Fig. 2: Development of the Construction Sector in

the Republic of Moldova from 2018 to 2022

When examining the figures on planning

permission granted for the construction of

residential properties (Figure 3), it is evident that the

number of permits in the Chisinau municipality

significantly increased in 2021 after the COVID

period. However, it is important to note that the

information for 2023 is not yet complete, as data for

the fourth quarter is still outstanding.

Fig. 3: Building permits issued for constructing

residential buildings within Chisinau municipality

Analyzing the same period about the building

permits issued, the structures that were put into

service were examined in Figure 4. The data for the

10000

20000

30000

40000

50000

60000

70000

80000

North Centre South

3605

22049

4587

13558

77217

14336

Building permits issued for constructing residential

buildings

Dwellings put into operation

252 173 140 129 181 89

1869 1643 1940

3796

2563

1432

500

1000

1500

2000

2500

3000

3500

4000

2018 2019 2020 2021 2022 2023

residential buildings individual houses

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Doina-Cezara Albu, Ion Serbanoiu

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fourth quarter is still outstanding, thus the

information for 2023 remains incomplete.

Fig. 4: Dwellings put into operation in Chisinau

municipality

Upon analyzing Figure 2 and Figure 3, it

becomes evident that the volume of buildings put

into operation in Chisinau municipality is

significantly higher than the number of building

permits issued.

The capital reconstruction percentage of

residential buildings within Chisinau municipality

was analyzed in comparison to the previous year, as

shown in Figure 5.

Fig. 5: Percentage change in capital repair works

compared to the previous year, in comparable prices

The statistical analysis indicates the evolution of

the residential construction industry in Chisinau.

The buildings are planned with an emphasis on

energy efficiency based on outdated regulations,

while the thermal resistance and thermal

transmittance values are not standardized.

The primary issue regarding energy efficiency

in newly constructed buildings is the absence of a

methodology for evaluating their energy

performance. Currently, some regulations require

rectification and completion.

As a starting point for designing new buildings

that aim for almost zero energy consumption, the

authors suggest the application of the Romanian

methodology MC 001-2022.

Another issue is the importation of materials

instead of local ones. The Republic of Moldova has

reserves of limestone blocks that possess high

physical-mechanical properties, [26]. Furthermore,

the limestone stock has been segregated into two

quarries that are ready for exploitation, 13 reserve

quarries, and 44 quarries that are already in

exploitation, [13].

3 Problem Solution

The authors suggest utilizing limestone blocks with

polyurethane foam as thermal insulation between

two layers of masonry for residential buildings

(Figure 6).

This wall structure can be used for both infill

and load-bearing walls. The wall thickness is 460

mm, and a reinforcement mesh is placed at every

fourth masonry layer to provide higher seismic

resistance, [26].

Fig. 6: Proposed construction solution for residential

building walls

Calculations were performed to determine the

dew point (Figure 7) for the presented wall

construction solution, using the following initial

data: relative humidity of 55%, indoor temperature

of +20 °C, outdoor temperature of -25°C in the

central area of Moldova, and 5 cm of polyurethane

foam insulation on the walls.

11116

16077

12269

18349

5980

9654

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

2018 2019 2020 2021 2022 2023

68,2

97,2

127

86,1

86,9

84,9

69,3

162,7

025 50 75 100 125 150 175

2015

2016

2017

2018

2019

2020

2021

2022

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Doina-Cezara Albu, Ion Serbanoiu

E-ISSN: 2224-3496

Volume 20, 2024

Fig. 7: Dew point graph of the analyzed

construction solution

The data presented in Figure 7 indicates that the

building solution under investigation has a high

level of thermal insulation, preventing the dew point

from reaching 10.7°C.

Based on the Romanian methodology MC 001-

2022, [27], the thermal resistance and thermal

transmittance of the construction solution presented

in Figure 6 are determined (Table 1).

Table 1. The centralizer of results obtained on

thermal efficiency calculation

Indicator

Value

Unit of

measurement

Total unidirectional

thermal resistance

4.49

m2∙K/W

Unidirectional

thermal transmittance

0.22

W/ m2∙K

Total corrected

thermal resistance

4.22

m2∙K/W

Total corrected heat

transmittance

0.24

W/ m2∙K

When determining the thermal resistance of the

analyzed solution (Table 1), the subsequent data

were collected.

- The thermal conductivity of limestone blocks is

0.33 W/mK with a thickness of 0.2 m for one

block, determined from laboratory work.

- The thermal conductivity of polyurethane foam

is 0.022 W / mK, according to the technical data

sheet, at a thickness of 0.06 m.

- The thermal conductivity of cement mortar

plaster is 0.93 W/mK with a thickness of 0.02 m,

as reported in the technical data sheet.

In terms of sustainability, the solution satisfies

the fundamental requirement of being energy

efficient, and limestone blocks represent a long-

lasting and high-strength building material, [26].

The widespread implementation of the building

solution is expected to boost the revenue of

limestone quarries.

From an economic perspective, we conducted a

comparative analysis of construction solutions

implemented in practice, as shown in Table 2.

Table 2. Comparative analysis of construction

solutions in terms of price for 1 m3

Material

Quantity

Price, MDL

Price 1

m3,

MDL

Autoclaved aerated

concrete

21 units

171

3591

Bituminous

membrane

1.2 m2

70.1

84.12

Adhesive

7.28 kg

3.32

0.97

Reinforcing mesh

2.5 m2

13.6

34.

Plaster

12.48 kg

10.59

5.29

Polystyrene

2.5 m2

105

262.5

Plastic plug with

plastic pin and

long expansion

zone

20 units

2.8

Masonry

workmanship

500

Insulation

workmanship

Total

4600.87

BRIKSTON

1 m3

2350.17

Bitumen primer

0.365 m2

63.3

23.1

Mortar

0.117 m3

960

112.13

Reinforcing mesh

2.62 m2

13.6

35.63

Plaster

15.71 kg

10.59

166.34

Polystyrene

2.62 m2

105

275.1

Plastic plug with

plastic pin and

long expansion

zone

21 units

2.8

58.8

Masonry

workmanship

770

Insulation

workmanship

Total

3858.28

Limestone block

1 m3

810

Tar cardboard

1.35 m2

10.45

14.11

Mortar

0.15 m3

750

113.15

Reinforcing mesh

5.68 m2

130.69

Polyurethane foam

1 m3

155

Insulation

workmanship

Masonry

workmanship

550

Total

1772.95

Price 1 m3, EUR

AAC masonry

235.34

BRIKSTON brick masonry

197.35

Limestone block masonry

90.69

The prices listed in Table 2 were obtained from

the catalog of average sales prices for construction

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materials, sourced from manufacturers and

importers in the Republic of Moldova in 2023. The

exchange rate used for the calculations was 19.55

MDL per EUR.

Economically speaking, using the proposed

construction method, 1 cubic meter of masonry will

be 2.6 times less expensive than masonry built with

autoclaved aerated concrete blocks and 2.2 times

less expensive than masonry made with BRIKSTON

ceramic blocks.

4 Conclusion

The research reveals the current state of

sustainability in construction in the Republic of

Moldova. As shown in Figure 2, Figure 3 and

Figure 4, the number of buildings in Chisinau

municipality has increased in recent years, but the

sustainability problem is not solved at the local

level.

Taking into account Moldova's limestone

resources, the use of local materials for construction

would facilitate sustainable development in the

country.

The proposed construction solution has several

advantages, including local and natural materials are

used; thermal insulation over time does not require

replacement; in terms of energy efficiency, it meets

the requirements of near-zero energy consumption;

from an economic point of view, it is cheaper than

the construction solutions currently used in

residential buildings.

However, a drawback of the proposed solution

is the complexity of the masonry system, which

requires two layers and frequent application of foam

and reinforcement mesh to enhance seismic

resistance.

Ensuring the sustainability of residential

buildings in Moldova should be a priority for the

construction sector. Local materials must be used

for this purpose and any new regulations or projects

relating to energy efficiency should consider the

availability of local resources.

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Contribution of Individual Authors to the

Creation of a Scientific Article (Ghostwriting

Policy)

- Ion Serbanoiu is conducting research and

investigation, specifically performing experiments

and collecting data/evidence.

- Doina-Cezara Albu is responsible for all other

parts of the research.

Sources of Funding for Research Presented in a

Scientific Article or Scientific Article Itself

No funding was received for conducting this study.

Conflict of Interest

The authors have no conflicts of interest to declare.

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(Attribution 4.0 International, CC BY 4.0)

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Creative Commons Attribution License 4.0

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DOI: 10.37394/232015.2024.20.7

Doina-Cezara Albu, Ion Serbanoiu

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