Improving Waste Management at Construction Sites—Evidence from a Comparative Study in Poland and Slovakia

Abstract

Construction waste management remains a critical challenge for improving project efficiency and sustainability. Despite extensive research, there is still a lack of comparative and up-to-date empirical studies addressing both material and non-material waste across different national contexts, limiting the identification of optimisation priorities. This study addresses this gap by analysing construction-site waste in Poland and Slovakia. A mixed-method approach was applied, combining quantitative, qualitative, and comparative analyses based on a questionnaire survey conducted in 2024 among construction contractors. Respondents evaluated 34 waste factors using a four-point scale in terms of frequency and importance. The results indicate that errors and inconsistencies in design documentation represent the most significant and frequent source of waste in both countries (importance: 3.60 in Poland, 3.12 in Slovakia; frequency: 3.40 and 2.87). Other critical factors include excessive workload of employees, delays in construction processes, quality defects in executed works and damage to completed works. Differences were also observed, particularly in change management and stakeholder relations. The findings highlight key areas for improving waste management, especially in design coordination, communication, and workforce organisation, supporting the implementation of BIM and Lean Construction.

1. Introduction

The construction sector is one of the largest consumers of natural resources and a significant source of solid waste [1]. Its environmental impact spans the whole life cycle of a built asset—from material production and transport, through the construction process, to operation and eventual demolition. In this context, construction waste (CW) may be understood as any material or activity occurring during the building process that does not add value to the final product [2]. Inefficient material management and poor organisation of construction processes lead to excessive energy consumption, environmental degradation, and increased volumes of waste sent to landfill, which contradicts the objectives of sustainable development [3], particularly those related to responsible consumption and production and sustainable cities.

According to Eurostat statistics, in 2022 construction and demolition waste generated in the 35 European countries listed in Figure 1 amounted to a total of 870.14 million tonnes, representing nearly 35% of the approximately 2.5 billion tonnes of waste generated across all economic sectors, including households [4]. This very high share highlights the importance of effective management of construction-related waste.

As shown in Figure 1, the highest volumes of construction waste were recorded in France and Germany. Poland ranks eighth in the comparison, while Slovakia occupies twenty-third place. A broader temporal and geographical perspective is provided by World Bank data. Statistics published by the World Bank Group, covering the period 2010–2020 and 73 countries, indicate that the largest annual quantities of construction and demolition waste were generated in China (approximately 1.5 billion tonnes), the United States (534 million tonnes), Germany (275.41 million tonnes), and France (236.3 million tonnes) [5].

The European Union has implemented strategies aimed at improving waste management, including construction waste. Article 4 of the Waste Framework Directive 2008/98/EC establishes a five-step waste hierarchy, providing a policy framework for Member States [6]. The most recent revision of the Directive was published in 2025 [7]. According to a World Bank Group report, 86% of the 217 countries analysed have national legislation or guidelines governing solid waste management, with this figure rising to 96% among high-income countries [8]. In Poland, waste management is regulated by the 2012 Act [9], together with subsequent amendments. Among the most recent changes, regulations introduced in January 2025 specify rules for the management of construction and demolition waste, including mandatory selective segregation, which is the responsibility of the waste producer. In Slovakia, waste management, including construction and demolition waste, is governed by Act No. 79/2015 Coll. on Waste, as amended [10]. Responsibility lies with the waste producer or holder, while minimum material segregation requirements are defined in Decree No. 344/2022 [11].

The construction industry, as one of the key sectors of the economy, should play a leading role in implementing modern and efficient systems for managing investment modern and efficient systems for manging investment processes [12]. One of the major factors disrupting these processes is waste—understood not only in terms of material loses, but also inefficiencies resulting from poor management, inadequate coordination, ineffective stakeholder collaboration, and the influence of external factors.

The literature offers numerous studies highlighted the importance of efficiency and sustainable development within the AECO sector (Architecture, Engineering, Construction, and Operation) [13,14]. However, comprehensive analyses that account for both material and non-material forms of waste and that consider national contexts remain limited. Most existing studies focus primarily on physical waste management, overlooking less tangible but equally significant sources of inefficiency, such as design documentation errors, ineffective communication, workflow interruptions, or excessive decision-making complexity [15,16]. Moreover, there is a notable lack of international comparative studies that would enable the identification of both universal and locally conditioned sources of waste [17].

Despite the extant literature describing general sources of waste (e.g., overproduction, waiting, defects according to Lean principles), there is a paucity of empirical comparisons between countries with similar economic structures but different sectoral practices, such as Poland and Slovakia. Existing studies have focused mainly on municipal waste or individual countries, ignoring the specific nature of construction sites and the opinions of expert contractors. Consequently, the acknowledgement of regional particularities proves inadequate, as there is a paucity of understanding regarding the manner in which distinct sectoral conditions influence the composition and magnitude of waste in Central European nations. Additionally, there is a paucity of contemporary quantitative data concerning the significance and frequency of waste factors. This has resulted in the inability to identify optimisation priorities, particularly within the contexts of Lean and BIM. Despite the proven effectiveness of Lean Construction and BIM [18,19], there are limited opportunities for practical implementation. A paucity of research has been identified concerning the reasons for the low level of implementation in Poland and Slovakia, among other countries.

In recent years, numerous studies have addressed the problem of construction waste using various research strategies. For instance, Mohammed et al. applied a life-cycle approach focused on the 3R framework (reduce, reuse, recycle), with an emphasis on long-term sustainability [20]. Amaral et al. adopted a mixed-methods design, combining field data from various construction companies with qualitative observations of the making-do phenomenon, analysing both causes and contextual interrelations [21]. Białko and Hoła conducted structured interviews with general contractors to identify waste reduction methods [22]. Emmanuel et al. applied a Likert-based questionnaire to explore barriers to Site Waste Management Plans (SWMPs) [23]. Bajjou and Chafi conducted a statistically grounded study based on 27 literature-based waste factors validated by Moroccan experts, but limited to a single national context [15]. Some earlier studies, such as those by Formoso et al., based their analysis exclusively on empirical data collected from construction sites in Brazil, which limits the geographical and institutional scope of their findings in comparison to the present study, which examines and contrasts data from two distinct national contexts [17].

The literature also includes studies that adopt specialised analytical perspectives. Domingo examined the relationship between complex healthcare building features and construction waste generation using semi-structured interviews and a questionnaire survey, applying a life-cycle perspective; however, the study focused primarily on material waste and its causes across project stages [24]. Botchway et al. identified four key competency groups—each comprising a set of detailed skills—affecting waste minimisation in the construction phase, based on a questionnaire survey and factor analysis conducted among professionals in Ghana, a developing country [2]. Zhao et al. investigated contractors’ behavioural attitudes towards construction waste resource utilisation using a combination of questionnaire methods and behavioural experiments, with a primary focus on material waste [25]. While some studies (e.g., Bajjou and Chafi; Botchway et al.) consider both material and organisational aspects of waste, they are situated in African construction contexts. This indicates that the existing empirical evidence may be shaped by region-specific conditions, which may limit the transferability of findings to European construction markets. Consequently, there remains a lack of comparative, empirically grounded research conducted in European contexts that simultaneously captures both material and non-material dimensions of waste. This gap provides the motivation for further investigation, particularly in the context of Central European construction markets.

In contrast to these approaches, the present study addresses both a scientific and an applied problem. The scientific problem lies in the limited understanding of how material and non-material forms of waste co-occur and differ across national construction contexts, particularly in Central Europe, where comparative empirical evidence remains scarce. The applied problem concerns the lack of an up-to-date basis for identifying priorities for waste reduction at construction sites and for supporting the implementation of improvement-oriented solutions, including Lean Construction and Building Information Modelling (BIM).

Accordingly, the aim of the study was to identify and compare current sources of waste at construction sites in Poland and Slovakia. To achieve this aim, the study pursued the following objectives:

• to assess the frequency and perceived importance of 34 waste factors identified through the literature review;
• to compare the results obtained in two neighbouring countries with partially similar economic backgrounds but different sectoral characteristics;
• to identify those waste factors that may be considered common across both contexts and those that appear to be country-specific; and
• to indicate areas in which further optimisation may be supported by Lean Construction and BIM-related practices.

To address these objectives, a mixed-method approach was adopted, combining quantitative, qualitative-interpretative, and comparative analyses. A questionnaire survey was employed—a data collection method widely used in construction management research, particularly for obtaining expert opinions from larger respondent groups within a relatively short time frame [26]. The survey targeted construction contractors. Respondents assessed waste factors identified through a literature review in terms of their importance (impact) and frequency of occurrence, enabling the collection of quantitative data suitable for statistical analysis and their interpretation within a qualitative, contextual framework.

The scientific contribution of the study lies in providing a comparative and empirically grounded perspective on construction-site waste in two Central European countries, while accounting for both tangible and intangible forms of waste. The practical contribution lies in identifying waste factors of highest relevance to contractors and in indicating areas that may support the improvement of waste management processes in construction practice. Compared to previous studies, the methodological innovation of this article lies in its unique combination of: (1) the simultaneous inclusion of both material and non-material types of waste; (2) empirical comparison between two national contexts; (3) a time-based reference to earlier Polish studies; (4) a standardised set of 34 waste factors derived from the literature and (5) a focus on contractors’ perspectives.

The relevance of the study is therefore threefold. From an economic perspective, it helps identify inefficiencies that may generate avoidable costs. From an environmental perspective, it supports more sustainable construction practices through improved waste reduction. From a practical and managerial perspective, it provides an evidence base for better-targeted actions aimed at improving construction-site performance.

2. Literature Review

Already in the 1980s, Taiichi Ohno identified seven types of waste observed in manufacturing: waste of overproduction, time on hand (waiting), transportation, processing, stock on hand (inventory), movement, and making defective products [27]. This classification, rooted in the Toyota Production System, became foundational for understanding inefficiencies across industries. Efforts to reduce these wastes marked a turning point in manufacturing development, influencing other sectors, including construction, through the concept of Lean Construction, whose core principle is the elimination of waste and the maximisation of added value [28,29]. Recent systematic reviews confirm Lean Construction’s role in enhancing sustainability and efficiency, with tools like Last Planner System reducing waste by 20–30% in global case studies [12,13,30].

Waste in construction frequently arises from process-related errors, including inappropriate work methods, poor planning, or low execution quality [31]. Other detrimental factors include work inefficiencies, irregular work patterns, employee overload, and underutilisation of workforce potential [32]. Management inefficiencies are significant causes, stemming from inadequate control, flawed resource allocation decisions, and suboptimal distribution of resources [31]. Empirical studies using structural equation modelling (SEM) identify critical factors like design changes, material shortages, and labour variability as key drivers, explaining up to 60% of variance in waste generation [16].

Additional sources of waste may result from disruptions in external flows, environmental influences, and poorly organised workspaces, such as limited working areas, overcrowding, or inadequate site conditions. Material and site-related wastes losses can also occur due to damage to previously completed elements [33], inappropriate material substitutions, acts of vandalism, or theft [34], as well as unfavourable project locations leading to excessive rental or acquisition costs [35]. The literature also identifies specific non-value-adding forms, such as provisional work carried out without sufficient resources for completion (making-do) [36], informal acceptance of deviations from requirements from a quality management perspective (task diminishment) [37], or the deliberate use of one form of waste to reduce another (buffering) [38].

Other cognised sources include errors and inconsistencies in design documentation, delays in payments to or from contractors, and administrative difficulties, including permit acquisition and limited access to modern technologies [39]. Stakeholder relations play a significant role in waste reduction, with tensions between the client and contractor or between contractors and suppliers—often stemming from a lack of trust-being identified as common on-site issues [39,40]. Waste can also take a physical form, such as material losses resulting from poor handling or inadequate site infrastructure [40,41]., or the abandonment of unfinished works requiring completion at a later stage by the same or a different crew [41]. Further causes include delays in payments, insufficient training, and a lack of worker awareness regarding sustainable development and environmental impacts [15].

In the European context, construction and demolition waste (CDW) accounts for 38.4% of total waste generation in the EU in 2022 [14]. Poland generated 122.8 million tonnes of total waste in 2023, with construction as a major contributor amid housing and infrastructure booms [15], while Slovakia’s waste generation remains lower per capita [16].

The identification of waste that threatens or occurs on site is a crucial first step towards its reduction. The subsequent stage involves planning strategies for its elimination or at least mitigation. This can be achieved through the previously mentioned Lean Construction concept, as well as advanced technologies enabling early detection and management, such as Building Information Modelling (BIM), which uses digital representation of building assets for information management, or more advanced Digital Twin, allowing real-time data utilisation [42,43]. Strategies grounded in sustainable development principles, such as Life Cycle Assessment (LCA) [44], may also be applied, alongside the integration of artificial intelligence tools for waste reduction in construction [45].

On the basis of the literature review conducted in the previous study [46], a systematic identification of waste factors occurring in the construction sector was undertaken. This process included an analysis of classical Lean concepts (Ohno [27], Koskela [29]), which constitute the theoretical foundations for waste identification, followed by a structured categorisation of factors reported in the literature according to their nature and area of occurrence. In particular, factors were distinguished in relation to: (1) external conditions (e.g., stakeholder relationships, payment delays, design documentation errors), (2) construction process management (planning, supervision, resource allocation, implementation of changes), (3) execution of construction works (quality defects, delays, rework), (4) resources and communication within the supply chain (material logistics, storage, cooperation with suppliers), as well as (5) specific categories of waste developed within the Lean Construction literature.

The adopted framework does not constitute a new theoretical classification, but rather an operationalisation of categories already present in the literature for the purposes of empirical investigation. The standardised set of factors enables replication in questionnaire-based studies across different national contexts and in subsequent years, thereby facilitating longitudinal analysis and verification of the continued relevance of particular types of waste.

The criteria for selecting the factors included: the recurrence of a given type of waste in the literature, its emphasised significance, the possibility of operationalising it within a questionnaire survey, its direct relevance to construction site conditions (rather than exclusively to macroeconomic or municipal waste levels), and the feasibility of assessing it in terms of both frequency and importance, including its impact on time, cost, and quality of works.

As a result, a unified set of 34 waste factors was identified, encompassing both material and non-material losses (organisational, managerial, and communication-related). The literature sources underlying the identification of each factor are presented in

Table 1. Waste factors identified in the literature review and their bibliographic sources.

Waste Factor/Type	Reference(s) Underlying the Waste Factor
External factors
Mistakes and inconsistencies in design documentation	Leśniak (2012) [39]
Bad relations between the client and the contractor	Leśniak (2012) [39]
Delays in payments from the client or to subcontractors	Leśniak (2012) [39]
Waste related to external factors, e.g., mistakes in external flows; environmental factors	Serpell et al. (1995) [31]
Location-related waste: excessive rental or purchase price, suboptimal use of space, inefficient location (for example too far from suppliers)	Birek et al. (2003) [35]
Burglary, vandalism	Formoso et al. (1999) [34]
Construction management
Ineffective/too slow/too fast/unprofitable introduction of changes	Authors’ own elaboration
Excessive workload of employees	Czaczkowski (2014) [32]
Waste in supervision—ineffective/insufficient control: poor or no supervision	Alarcón (1997) [33]
Negligence in preparing the necessary arrangements/permits	Leśniak (2012) [39]
Managerial waste, for example poor decision allocation, ineffective planning, unclear strategies and procedures	Serpell et al. (1995) [31]
Poorly planned workplaces: lack of places, too many people working in a limited space, poor working conditions; lack of safety	Alarcón (1997) [33]
Underutilisation of employee potential	Czaczkowski (2014) [32]
Construction works
Errors and quality defects in executed works, non-compliance with the intended use	Ohno (1988) [27]
Delays in execution of construction works	Koskela (1992) [29]
Damage to completed works	Alarcón (1997) [33]
Unfinished work—rework, minor finishing works left behind when the crew leaves the workstation—completed later, not necessarily the same crew	Fireman et al. (2015) [41]
Waste of over-processing—any activity that is not necessary to produce a product or service with the parameters and quality level required by the customer, for example non-optimal use of material, machine, energy and labor, waste of material	Ohno (1988) [27]
Inefficient work of the employee	Bølviken et al. (2014) [38]
Work irregularity, e.g., periods of intensive activity followed by stoppages	Czaczkowski (2014) [32]
Waste of waiting—machines, workers waiting for the materials, tools, instructions, or information needed to get the job done	Ohno (1988) [27]
Waste of movement—any unnecessary physical effort performed by worker	Ohno (1988) [27]
Overproduction—producing products or services in advance or in greater quantity than currently required	Ohno (1988) [27]
Resources, communication with suppliers
Improper handling leading to material waste	Ankomah et al. (2015) [40]
Storage of materials in inappropriate places	Alarcón (1997) [33]
Substitution: inadequately, poorly selected construction equipment	Formoso et al. (1999) [34]
Excess inventory—more than the necessary minimum quantity of materials, semi-finished products, work in progress and finished products	Ohno (1988) [27]
Poor communication between contractor and supplier, lack of mutual trust	Ankomah et al. (2015) [40]
Insufficient water and electricity infrastructure required for construction works	Fireman et al. (2015) [41]
Unnecessary transport—unnecessary movement of products or materials	Ohno (1988) [27]
Contractor’s lack of access to modern technologies	Leśniak (2012) [39]
Selected waste from literature review
Task diminishment (task reduction, loss, diminution)—failure to perform the work in accordance with the specification	Patton (2009) [37]
Making–do refers to starting or continuing work before the required conditions for completion are met, e.g., sufficient supplies	Koskela (2004) [36]
Buffering: a strategy in which one type of waste is used to reduce others	Bølviken et al. (2014) [38]

.

This review synthesizes waste categories into a framework adaptable for empirical validation (e.g., via Pareto analysis).

Table 2. Key waste categories and examples.

Category	Examples	Frequency in the Literature
Process	Overproduction, waiting	High [27,31]
Material	Material damage, theft	Medium [33,34]
Management	Poor planning, delays	High [16,39]
Organisational	Making–do, task diminishment, buffering	Emerging [36,37,38]

provides a synthetic summary of the principal waste categories distilled from the literature, together with representative examples and an indication of their prominence in earlier research.

The purpose of the literature review was to systematically identify, classify, and synthesise waste factors reported in previous research, with particular emphasis on those relevant to construction site conditions and suitable for empirical investigation. This process enabled the development of a structured and operational set of waste factors that can be assessed in terms of both their frequency and perceived importance.

The identification and structuring of waste factors in the literature provide the foundation for empirical verification in real construction environments. In this study, the compiled set of waste factors is used as a standardised analytical framework enabling comparative analysis between different national contexts and across different time periods. Such an approach allows not only the identification of the most significant sources of waste, but also the assessment of their changing importance in contemporary construction practice.

Accordingly, the literature review provided the basis for defining the set of waste factors, which were subsequently used in the questionnaire and in further quantitative and qualitative analysis.

3. Materials and Methods

This study adopts a holistic approach to the concept of waste in construction, encompassing not only material waste, but also inefficiencies arising, for example, from inadequate supervision, deficiencies in management practices, and ineffective communication. This perspective aligns with a research trend that treats waste as a multidimensional phenomenon extending beyond the classical notion of physical waste. In previous study [46], a comprehensive literature revie was conducted, which led to the identification 34 types of waste in the construction sector. The sources supporting this review are presented in Section 2 (Literature Review). The present study builds upon this earlier work by further investigating current waste and strategies for their reduction. The research scope was extended to include the Slovakian construction sector, alongside the Polish one. This allowed for a comparative analysis between the two counties and the examination of current international trends, enabling the identification of potentially universal forms of waste and differences resulting from local work practices. The study adopts a mixed-method approach, combining quantitative, qualitative (interpretative), comparative, and time-based analyses. The research framework is illustrated in Figure 2.

The statistical population was finite, static, and multidimensional [37,38], comprising professionals involved in construction works in Poland and Slovakia. The research design was purposeful, as the survey was specifically targeted at a defined group—building contractors—consistent with the study’s thematic scope. Within this defined group, a non-probability (convenience) sampling technique was used, limited to respondents who voluntarily agreed to participate. The use of a non-probability convenience sampling approach was determined by practical and organisational constraints typical for research conducted within the construction sector, including limited accessibility of respondents, time constraints of professionals, and the voluntary nature of participation. This approach is commonly applied in construction management studies, particularly when targeting experienced practitioners, whose availability for research participation is inherently restricted [15,24,47]. Although the sampling method does not ensure full statistical representativeness, it should be noted that the respondents were predominantly experienced professionals occupying senior or decision-making positions within construction companies. This is reflected in the respondent profile (Table 2), where the majority had several years of professional experience and held managerial or engineering roles. Consequently, the findings reflect practitioner perspectives grounded in professional experience, which is particularly relevant for interpreting construction site processes.

Empirical data were collected using a standardised questionnaire survey, as this method facilitates quantitative assessment and supports the objectivity of findings [47]. The survey conducted in Slovakia employed the same questionnaire as used in Poland, allowing for joint analysis and comparison. In both countries, the questionnaire was distributed online. The collected data are primary in nature. At the same time, the questionnaire was designed in reference to prior Polish studies conducted in 2016 and 2021, enabling a quasi-longitudinal comparison. The questionnaire consisted of two main parts: a demographic (profiling) section and a substantive (core) section. The first section of the questionnaire concerned the respondents’ profiles, including specialisation (civil engineering, mechanical installation), the characteristics of their employing organisation (general contractor of subcontractor, company size), job position, professional experience, and the project delivery method applied. This section also included questions regarding the awareness and use of Lean Principles and Building Information Modelling (BIM), the application of which in waste reduction could influence the validity of the data analysis. The second part focused on the assessment of waste factors. Respondents were asked to rate each factor on a four-point scale in terms of importance, impact, e.g., on time, cost, quality, and frequency of occurrence. An option to indicate additional, non-listed waste factors was also provided. Although the scale is ordinal, arithmetic means were used for descriptive and comparative purposes, as they enable clearer differentiation and ranking of waste factors, which was essential for cross-country analysis. Given that the study focuses on identifying relative importance and frequency rather than statistical inference, this approach is considered appropriate and was complemented by qualitative interpretation.

The study analysed both quantitative ordinal variables (ratings of frequency and importance/impact) and qualitative variables (respondents’ characteristics, declared knowledge and use of Lean and BIM). The applied rating scales allowed for statistical processing of the data as well as qualitative interpretation of the results.

Data analysis included: Quantitative analysis—calculating arithmetic means of each waste factor separately for Poland and Slovakia; identifying the most frequently occurring and most significant types of waste; Comparative analysis—contrasting results between the two countries and comparing them to findings from 2016 and 2021; Qualitative (interpretative) analysis—interpreting the quantitative results in light of previous research, national contexts, and the reported use of Lean and BIM tools. The conclusions drawn from the analyses were used to identify potentially critical areas of waste and to formulate recommendations for reduction strategies based on evidence from the literature.

All research procedures adhered to applicable ethical guideline and regulations. Informed consent was obtained from all participants, with assurances of anonymity. The data collected were general in nature, with no sensitive or personally identifiable information recorded.

4. Results

In Poland and Slovakia, the execution of the survey was hindered by the limited motivation of potential participants. Only 10.22% (6.67% in 2016, 37.5% in 2021 and 30.56% in 2024) were correctly completed and returned, put of a total of 450 distributed forms. Nevertheless, the majority of responses came from experienced professionals with at least six years of work experience (73% of respondents in 2016, 88% in 2021, and 72% in 2024). The 2024 respondents in Poland were predominantly individuals holding senior positions in large construction companies, typically acting as general contractors. This profile is broadly consistent with those from the 2016 and 2021 surveys [46].

In Slovakia, 52 correctly completed questionnaires were obtained, with answers from contractors. The respondent profile was broadly similar to that of Polish survey with the notable difference that their workplace was predominantly in Slovakia, and the companies they worked for were small enterprises employing between 10 and 49 permanent employees.

The data concerning the profile of respondents from 2024 survey in both the Polish and Slovakian construction sectors are presented in

Table 3. Profile of respondents to the 2024 survey in the Polish and Slovakian construction sectors.

	Poland	Slovakia
Experience
Less than 2 years	18%	4%
3–5 years	9%	0%
6–10 years	27%	29%
11–20 years	27%	54%
Over 20 years	18%	13%
Company size
Up to 9 permanent employees	9%	13.5%
10 to 49 permanent employees	27%	44.2%
50 to 249 permanent employees	9%	25%
More than 250 permanent employees	55%	17.3%
Work position
Contract Manager/Site Manager/Founder/Director/	36%	40.4%
Works Manager	18%	0%
Site engineer	36%	25%
Manager/Engineer for bidding, contracting, documentation	9%	17.3%
Administrative Position	0%	0%
Manual worker	0%	0%
Other	0%	3.9%
Industry
General Contractor	100%	80.8%
Subcontractor in the construction industry	0%	11.5%
Subcontractor in the sanitary engineering sector	0%	0%
Subcontractor in the electrical engineering sector	0%	7.7%
Client’s team	0%	0%
Workplace (multiple–choice question *)
Poland	100%	0%
Slovakia	0%	100%
Czech Republic	0%	15%
Other	9%	6%

* Respondents were asked to indicate all countries in which they had worked, including both current and past construction projects.

.

Respondents were asked to assess waste at the construction site on a four-point scale in terms of importance, impact, e.g., on cost, time, and quality), and degree of occurrence. For importance, a score of 1 indicated that the given waste was negligible, while a score 4 denoted it as significant. For the degree of occurrence, a score of 1 meant that the waste did not occur at all or occurred very rarely, whereas a score of 4 indicates that it was commonly present.

The results were grouped to enhance clarity into the following categories: external factors, construction management, production, resources, communication with suppliers, and selected waste from the literature review, and are presented in

Table 4. Results of respondents’ Assessment of waste at the construction site in the 2024 survey conducted in Poland and Slovakia.

Waste Factor/Type	Degree of Occurrence * 1–4		Importance/Impact of Waste Factors/Types, e.g., on Cost, Time, Quality * 1–4
	Poland	Slovakia	Poland	Slovakia
External factors
Mistakes and inconsistencies in design documentation	3.40	2.87	↓3.60	3.12
Bad relations between the client and the contractor	2.10	1.88	2.80	2.94
Delays in payments from the client or to subcontractors	2.10	2.54	2.70	2.90
Waste related to external factors, e.g., mistakes in external flows; environmental factors	1.80	1.79	2.70	2.63
Location-related waste: excessive rental or purchase price, suboptimal use of space, inefficient location (for example too far from suppliers)	2.10	1.81	2.20	2.58
Burglary, vandalism	1.70	1.96	2.11	2.33
Construction management
Ineffective/too slow/too fast/unprofitable introduction of changes	2.18	2.25	↓3.40	2.48
Excessive workload of employees	3.00	2.65	3.10	2.67
Waste in supervision—ineffective/insufficient control: poor or no supervision	2.00	1.92	3.00	2.43
Negligence in preparing the necessary arrangements/permits	2.30	1.94	2.90	2.40
Managerial waste, for example poor decision allocation, ineffective planning, unclear strategies and procedures	2.11	2.00	2.90	2.38
Poorly planned workplaces: lack of places, too many people working in a limited space, poor working conditions; lack of safety	2.09	2.15	2.70	2.63
Underutilisation of employee potential	2.30	2.04	2.60	2.67
Construction works
Errors and quality defects in executed works, non–compliance with the intended use	1.90	1.75	↓3.50	2.83
Delays in execution of construction works	3.10	2.06	3.20	2.92
Damage to completed works	2.80	2.31	3.10	3.06
Unfinished work—rework, minor finishing works left behind when the crew leaves the workstation—completed later, not necessarily the same crew	2.50	2.13	3.00	2.56
Waste of over-processing—any activity that is not necessary to produce a product or service with the parameters and quality level required by the customer, for example non-optimal use of material, machine, energy and labor, waste of material	1.80	1.77	2.70	2.33
Inefficient work of the employee	2.50	2.25	2.60	2.75
Work irregularity, e.g., periods of intensive activity followed by stoppages	2.09	1.94	2.50	2.60
Waste of waiting—machines, workers waiting for the materials, tools, instructions, or information needed to get the job done	2.00	2.12	2.50	2.63
Waste of movement—any unnecessary physical effort performed by worker	1.90	2.19	2.30	2.33
Overproduction—producing products or services in advance or in greater quantity than currently required	1.30	1.65	2.20	2.27
Resources, communication with suppliers
Improper handling leading to material waste	2.40	1.98	↓3.30	2.69
Storage of materials in inappropriate places	2.18	2.25	2.70	2.56
Substitution: inadequately, poorly selected construction equipment	2.00	1.98	2.70	2.81
Excess inventory—more than the necessary minimum quantity of materials, semi-finished products, work in progress and finished products	2.09	2.04	2.60	2.21
Poor communication between contractor and supplier, lack of mutual trust	2.10	2.31	2.60	2.65
Insufficient water and electricity infrastructure required for construction works	2.10	1.81	2.50	2.48
Unnecessary transport—unnecessary movement of products or materials	1.73	2.33	2.50	2.77
Contractor’s lack of access to modern technologies	2.00	2.21	2.30	2.33
Selected waste from literature review
Task diminishment (task reduction, loss, diminution)—failure to perform the work in accordance with the specification	2.10	1.63	↓2.80	2.62
Making-do refers to starting or continuing work before the required conditions for completion are met, e.g., sufficient supplies	2.20	1.85	2.70	2.54
Buffering: a strategy in which one type of waste is used to reduce others	1.50	1.98	1.80	2.48
* Rating calculated as an arithmetic mean Importance/impact of factors/types of waste, e.g., on cost, time, quality, where: 1 means—No impact or its negligible dimension (does not matter) 2 means—Low impact (unimportant) 3 means—Medium impact (medium important) 4 means—Big influence (very important)	The degree of occurrence, where: 1 means—Does not occur or occurs very rarely 2 means—Occurs sometimes 3 means—Occurs often 4 means—Always present

. For each of the 34 identified waste factors, arithmetic means were calculated separately for the importance and the degree of occurrence, based on the scores provided by the respondents. This statistical approach enabled the identification of both the most frequent and the most impactful types of waste, as perceived by respondents in Poland and Slovakia.

Within the external factors group, it should be noted that most respondents in both Slovakia and Poland worked under the Design-Bid-Build project delivery method. Across both countries, design errors were identified as the most important and most frequent source of waste at the construction site. Also commonly reported were delays in payments from the client or to subcontractors. Another significant waste in this group was poor relations between the client and the contractor.

In the construction management category, a key challenge identified in the Polish sector was the difficulty of managing changes, which are often interconnected, making effective change management a critical skill. In both countries, worker overloading was considered important and was also the most frequently occurring waste in this category; in Slovakia underutilisation of workers’ potential was additionally noted.

For construction works-related waste, Polish respondents ranked quality defects as the most important factor, while in Slovakia, damage to completed works—requiring rework—were given greater importance. Delays in execution works were common in both countries in this category.

In resources and communication with suppliers, Polish respondents most frequently cited improper handling of materials, which directly affects costs and project time, when reordering is required. In Slovakia, improperly selected equipment was considered more important, while poor logistics—unnecessary movement of products or materials—was the most frequent waste.

For wastes such as task diminishment, making-do, and buffering, respondents in Slovakia assessed their importance, similarly, rating them as having a low to moderate impact on construction time, cost and quality. In Poland, task diminishment and making-do received comparable importance scores, whereas buffering was rated significantly lower. The latter was also identified as the least frequently occurring waste in Poland, while in Slovakia it was the most commonly observed among these three types.

No additional wastes were suggested in the 2024 survey. However, the 2016 Polish survey identified other issues such as erroneous bid assumptions, insufficient winter heating, imprecise client requirements, equipment failures and flooding during star-up, client-imposed insufficient execution time, and overdesign [46].

To present the most significant and frequently occurring types of waste at construction sites, those receiving the highest scores listed in

Table 5. The most important and common waste at the construction site.

The Most Important Waste		The Most Common Waste
Poland	Slovakia	Poland	Slovakia
Mistakes and inconsistencies in design documentation	Mistakes and inconsistencies in design documentation	Mistakes and inconsistencies in design documentation	Mistakes and inconsistencies in design documentation
Errors and quality defects in executed works, non-compliance with the intended use	Damage to completed works	Delays in execution of construction works	Excessive workload of employees
Ineffective/not fast enough/too fast/unprofitable introduction of changes	Bad relations between the client and the contractor	Excessive workload of employees	Delays in payments from the client or to subcontractors

.

Among the wastes identified as both the most important and the most frequent by construction contractors in Poland and Slovakia, mistakes and inconsistencies in design documentation ranked highest. In Poland, additional emphasis was placed on the importance of errors and quality defects in executed works, as well as difficulties in implementing changes. In contrast, in Slovakia, higher importance was attributed to damage to recently completed works, which necessitated rework, leading to additional time and cost, and to interpersonal communication between the client and the contractor, which has a considerable impact on project progress. Respondents indicated that, apart from design errors, the most frequent wastes on Polish construction sites were delays in project execution and excessive employee workload—issues also noted in Slovakia—along with delays in payment between the client and the contractor.

Given that Lean Construction is aimed at eliminating non-value-adding activities [29], and, consequently, at reducing waste, respondents were asked about their familiarity with this method or related approaches. The responses are illustrated in Figure 3.

In Poland, when asked about their knowledge of Lean Principles, the majority (45%) stated that they were aware of them, but only to a limited extent, while 27% reported having no knowledge at all. More than half indicated that they had applied these principles in at least one project. In Slovakia, the majority (48%) reported no knowledge of Lean Principles or related tools, although 30% had applied them in at least one project.

5. Discussion

This study evaluates the prevalence and significance of construction site waste in Poland and Slovakia, focusing on its impact on cost, time, and quality. A mixed-methods approach combining quantitative, qualitative, and comparative analyses was applied.

The comparative perspective of the results is presented in detail in Table 4 (Section 4), where waste factors are analysed simultaneously for Poland and Slovakia in terms of both frequency and importance. The Discussion section builds upon this structured analysis, focusing on the interpretation of similarities, differences, and their implications in the context of existing scientific knowledge.

The analysis of the 2024 survey results revealed a number of similarities between the two countries, despite differences in respondent profiles—Polish participants predominantly represented large construction companies, whereas Slovakian respondents were mainly from small enterprises employing between 10 and 49 permanent staff. This disparity in sample structure is relevant when interpreting the results; however, both countries’ samples included respondents from companies of various sizes.

It should be acknowledged that the study employed a non-probability convenience sampling approach, which may introduce bias and limit representativeness. Respondents were selected based on accessibility and willingness to participate, which is common in construction management research. Notably, the sample consisted predominantly of experienced professionals in senior or decision-making roles, supporting the credibility of the insights. Nevertheless, the findings should be interpreted with caution when generalised. In addition, the results are based on respondents’ subjective assessments, which may be influenced by individual perceptions and experience. Future research could apply probability-based sampling methods (e.g., stratified or random sampling) to enhance representativeness, as well as incorporate additional data sources (e.g., case studies or objective project data) to reduce reliance on perception-based assessments.

Both in the Polish and Slovakian contexts, mistakes and inconsistencies in design documentation were most frequently cited and regarded as the most critical source of waste, consistent with earlier studies emphasizing the role of documentation quality in project delivery [15,46,48]. A similar conclusion was reached by Bajjou and Chafi, who identified design and documentation issues as one of the most frequently cited causes of waste in the Moroccan context [15]. This confirms that documentation-related inefficiencies constitute a consistent and transferable source of waste across different geographical and organisational contexts. While the study by Bajjou and Chafi was limited to a single national context and focused primarily on perceived waste factors, the current research expands the perspective by offering a comparative view across two Central European countries with different construction market structures. A comparable practitioner-based perspective was adopted by Botchway et al., who identified key competencies driving waste minimisation, including construction planning and sequencing, effective communication, supply chain management, and teamwork [2]. These competencies directly correspond with several waste factors identified in this study, such as delays in construction processes, inefficient coordination, excessive workload, and problems in communication with suppliers. This alignment suggests that both the occurrence of waste and its mitigation are strongly linked to organisational and managerial practices at the construction site level.

This highlights that one of the main practical problems in contemporary construction projects is ineffective information flow and coordination, which directly translates into the most critical forms of waste.

Given that most surveyed projects were implemented under the Design-Bid-Build system, design changes during the construction phase could lead to delays and increased costs. This reinforces the role of Building Information Modelling (BIM) as a tool supporting early error detection and more effective information coordination, which can mitigate these risks [18]. In Poland, 64% of respondents reported some knowledge of BIM, yet its use was limited; 56% reported using it in fewer than 10% of projects, and 44% in between 10% and 50% of projects [46]. However, the question was general in nature, and it remains unclear to what extent this implementation occurred or whether it referred merely to the use of a single application rather than a full methodology. Comparable data for Slovakia were unavailable.

The reduction in waste could also be supported by the application of Lean Principles, although awareness in both countries remains limited. More than half of the Polish respondents indicated that they had applied Lean Principles in at least one project; however, these declarations should be interpreted with caution, given the concurrently reported lack of in-depth knowledge of the methodology. Nevertheless, in light of the results obtained, this remains an interesting topic for more detailed investigation.

Although the study focuses on Poland and Slovakia, the identified patterns reveal both context-specific and potentially universal characteristics of construction waste. In particular, issues related to design documentation, workforce overload, and inefficiencies related to coordination and information exchange appear to transcend national boundaries and are consistent with findings reported in other regions. At the same time, differences observed between the two countries suggest that organisational structure, company size, and decision-making processes significantly influence the manifestation of waste. This indicates that while general waste reduction strategies may be transferable, their implementation should be adapted to local sectoral conditions.

From a practical perspective, the results may support contractors and project managers in prioritising key areas of intervention, particularly in improving design coordination, communication processes, and workforce organisation, which were identified as the most critical areas contributing to waste.

A notable difference was observed in the perceived significance of waste related to change management—ranked third in Poland but only nineteenth in Slovakia. A possible explanation lies in the shorter decision-making processes typical of smaller enterprises. Interestingly, in earlier Polish studies from 2016 and 2021, change management was not considered an important source of waste, which may indicate a new trend associated with the increasing complexity of large projects and the necessity to manage a greater volume of data [46]. It is worth noting that BIM can also support more efficient data exchange [24,25].

In Poland, particular attention was paid to the importance of quality of construction works, which may be linked to the more frequent presence of the client’s inspectors on large-scale projects. The refusal to accept works necessitates their rectification, which in turn may cause delays and incur additional costs. In Slovakia, higher significance was attributed to loses arising from damage to newly completed works, which require the return of construction teams or the engagement of new subcontractors. Polish contractors also pointed out that delays in the execution of works remain common compared to other types of waste. In both countries, excessive workload among employees was a recurrent issue—an occurrence also observed in previous studies [46], suggesting its potentially persistent nature. In Slovakia, delays in payments between stakeholders were also characteristic, with possible negative impacts on communication and the overall working atmosphere, a phenomenon similarly reported in studies from other countries, such as Morocco [15]. In that study, inadequate training and a lack of awareness regarding the principles of sustainable development were also highlighted, both of which further emphasise the importance of waste reduction [44].

From a theoretical perspective, the study contributes to construction management and sustainability-oriented research by extending the understanding of waste beyond traditional material flows to include organisational, managerial, and communication-related inefficiencies in real construction environments. The findings indicate that many of the most significant and frequent waste sources identified in the study are related to design documentation and coordination processes. In this context, Building Information Modelling (BIM), as highlighted in previous research, may support more effective information management and thus contribute to the reduction in such inefficiencies. While Lean Construction provides a useful conceptual framework for identifying non-value-adding activities, this study emphasises the importance of information-related processes in shaping waste occurrence. In the context of sustainable development, the study reinforces the need to integrate both material and non-material dimensions of waste into construction efficiency assessments.

In summary, this study provides up-to-date empirical data on waste occurring in the construction sector in two Central European countries, taking into account both its quantitative and qualitative dimensions. This enables a deeper understanding of the nature of the problem and serves as a foundation for developing targeted recommendations, decision-support tools, and future policies aimed at improving construction site performance.

Future research directions could include conducting detailed interviews to determine the causes and mechanisms underlying specific types of waste, cost-time analysis of the consequences of the most frequently identified losses, examination of the impact of BIM and Lean implementation on waste reduction, and comparative analyses involving a broader range of countries with diverse construction industry structures.

6. Conclusions

This study examined the prevalence and significance of construction site waste in Poland and Slovakia, considering both material and non-material forms and their impact on cost, time, and quality. Based on the conducted research, the following key conclusions can be drawn:

• The most critical source of waste in both countries is related to errors and inconsistencies in design documentation, which were identified as both the most significant and most frequent waste factor. This highlights the central role of information quality and coordination in construction processes.
• Waste in construction is multidimensional, extending beyond material losses to include organisational, managerial, and communication-related inefficiencies. These non-material forms of waste significantly influence project performance and should be systematically addressed.
• Both similarities and differences between countries were identified. While several waste types (e.g., documentation errors, workforce overload) appear to be universal, others are influenced by specific conditions such as company size, organisational structure, and decision-making processes.
• The results indicate key areas for practical intervention, particularly in improving design coordination, communication processes, and workforce management. In addition to documentation-related issues, important and frequently occurring waste factors include quality defects in executed works, damage to completed works, excessive workload of employees, delays in construction processes, and payment delays between stakeholders. These areas represent priority points for reducing waste at construction sites.
• The findings suggest the potential of digital and organisational approaches, such as Building Information Modelling (BIM) and Lean Construction, to support waste reduction. In particular, improved information management may contribute to mitigating the most critical and frequently occurring waste factors.
• From a scientific perspective, the study contributes to construction management and sustainability research by providing a comparative, empirical assessment of both material and non-material waste in two national contexts, using a standardised set of factors and a two-dimensional evaluation (importance × frequency).
• From an applied perspective, the study offers a basis for decision-making by practitioners and policymakers, supporting the identification of priority areas for improvement and the development of targeted strategies for enhancing construction process efficiency.

The study also provides a foundation for future research, particularly in expanding comparative analyses to other countries, conducting in-depth qualitative investigations, and evaluating the impact of BIM and Lean implementation on waste reduction in practice.