**1. Introduction**

Limited natural resources increase the need for environmentally friendly production of material goods. The work focuses on the quantitative minimization of the waste stream in the design of production processes of hall-type buildings in order to eliminate or reduce, to the necessary minimum, the amount of solid and gaseous waste.

Waste management in accordance with the 3Rs hierarchy (Reduce-Reuse-Recycle) can be used in construction engineering to create a new approach to system design that can significantly reduce environmental impacts [1]. The article attempts to assess the economic and ecological second recycling in the 3Rs waste management hierarchy in accordance with a circular economy (CE) [2]. Equally important, in the context of the reuse of steel elements, is the design phase of the product, striving to optimize the weight of the structure as well as accompanying elements and energy consumption [3]. This approach is known as design for the environment (DFE) [4] and allows for the analysis of the object at all stages of its life cycle, including in the reconstruction (post-exploitation) phase. The 3Rs hierarchy

**Citation:** Sobierajewicz, P.; Adamczyk, J.; Dylewski, R. Ecological and Economic Assessment of the Reuse of Steel Halls in Terms of LCA. *Appl. Sci.* **2023**, *13*, 1597. https://doi.org/10.3390/ app13031597

Academic Editors: Carlos Morón Fernández and Daniel Ferrández Vega

Received: 27 December 2022 Revised: 23 January 2023 Accepted: 24 January 2023 Published: 26 January 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

and the considered concept of the Indicative Environmental Assessment (EET) are part of the paradigm of sustainable development in the construction sector. The proposed methodology is aimed at using natural resources in such a state of equilibrium that they do not reach the point of exhaustion or non-renewal [5].

A lot of manufacturing companies, especially in Western Europe, which have introduced integrated Total Quality Environmental Management (TQEM) systems, are creating new concepts for environmentally oriented design. An important role in the process of preparing a pro-ecological construction investment is played by:


The procedures presented are in line with the requirements set by the European Union [10]. The criterion of environmental effects is one of the basic criteria taken into account when granting co-financing from structural and investment funds. Thus, the problem of the impact of structures on the environment has an economic dimension [11], both in terms of macro- and microeconomics.

In the literature on the subject, a depreciation of structural steel reuse can be observed from the point of view of only an economic criterion. Cullen and Drewniok [12] found that the economic cost of large-scale reuse of steel is at least as high as that of new steel. They analyzed economic costs without considering ecological costs. Similar conclusions were reached by Tingley and Allwood [13], who showed that the reuse of building structures is about 25% more expensive, which is a significant barrier to reuse. At the same time, they demonstrated that it is necessary to study the reuse costs for a wider range of projects in order to have a larger evidence base for the costs of reusing steel.

For projects with low ecological values, the production entity generates pollution translated into costs, which are direct external effects [14]. External costs constitute an additional burden for the polluter and are equivalent to the lost component of the natural environment. This state can be called a kind of waste of capital. As a result, a dual mechanism of degradation arises: on the one hand, environmental degradation and, on the other hand, degradation of the economy through an increase in costs and production value.

It is assumed that the average period of depreciation of commercial or production buildings of the hall type is 39 years [15]. Reconstruction or demolition of existing hall facilities, often with a steel structure, results from the reorganization of the functional space (services, production) and adapting them to the current technical and environmental requirements.

In 2019, the construction sector absorbed more than half of the world's steel production. Allwood and Cullen [16] found that 14% of the world's steel produced is used in infrastructure and 42% in buildings. Steel used in construction, due to the need to reduce greenhouse gas emissions, should come primarily from previous building structures; however, as research [10,17,18] shows, the reuse of steel sections is at the level of 6%, compared to 93% recycled. Obviously, we can always ask a question whether the demolition of materials and their use will be the trend of the future [19]? However, an increasingly faster transition from a linear economy (LE) [20] with high waste to a circular economy (CE) [21] based on the reuse of materials and recycling [22] is to be expected. Creating a market for building elements with different actors (such as traders, investors, designers, contractors) can prove to be a key solution for multiplying the reuse of these building elements and reducing the environmental pressure of the construction sector [23].

### *Brief Description of Environmental Performance Assessment Methods*

Reducing the environmental impact of processing and manufacturing activities, which consume large amounts of raw materials and energy inputs, is among the most important and difficult issues in the future. Effective measurement control and the introduction of new pro-ecological technologies will help reduce the pressure on the environment. A major achievement in the construction sector is the use of procedures to minimize waste [24]. Benchmarking standard operating procedures have been used for many years to optimize production processes and services [25]. They are implemented in the form of a predetermined organizational chart, consisting of 4 phases, which include, among other things:


The construction sector generates around 35% of the waste mass of the 2502.9 million tons generated in the EU-28 (2016 Eurostat data). Minimizing the amount of generated waste is the goal of the new EU development programs until 2050 (the European Green Deal, Europe's new agenda for sustainable growth, 2019) [26] based on the circular economy [27,28].

In the case of construction, new paths are defined for the CE strategy [29], which refers to cleaner production (CP) management procedures and are introduced in EU countries despite many barriers [30]. The common LCA methodology [31] contained in the ISO 14040- 44 guidelines is used to assess the environmental performance of products to minimize, reduce at source and recycle waste. ISO 14000 environmental management systems are implemented to produce environmental product declarations (EPDs) based on the ISO 14025 standard.

Other methods of environmental impact assessment are also noteworthy, such as:

	- Ecological Accounting Units (EAU) [36];
	- Product Line Analysis (PLA) [37];
	- LCC (Life Cycle Costing) [38].

Using these methods, it is possible to study the impact of products, materials, services and entire industrial processes on the environment in product life cycles in accordance with the idea of a circular economy initiated in the late 1970s [2] and developed in various procedures and methodologies, e.g., M. Braungart and W. McDonough "Cradle to Cradle" [39–41]. In construction, it means a physical description of the behavior of industrial systems [42] when raw materials taken from the environment are introduced into the system and pollutants and waste are removed and recycled [43]. A modern approach to industrial ecosystems is characterized by minimizing inflows and outflows from the system by creating eco-industrial parks [44,45].

These environmental assessment methods potentially support the demand, especially for certified Ecolabel products [46,47]. They are a tool for calculating environmental costs, however, in the environments of designers and contractors. Despite the fact that highly developed countries, including the EU, have started to pursue the direction of the circular economy, among others, through green public procurement [48], the market expects science to develop coherent green executive procedures.

There is a lack of simple and quick methods of environmental assessment of buildings and available material databases [49] with ecological parameters on the market. The authors of the study attempted a simple ecological assessment at the stage of design and economic calculation with secondary use of the main structural elements of the building.

#### **2. Purpose, Assumptions and Research Method**

Figure 1 presents the methodological framework of the presented scientific approach to determine the ecological and economic benefits of reusing the structural elements of a steel hall building.

**Figure 1.** The methodological framework of the presented scientific approach to determining ecological and economic benefits.

#### *2.1. Purpose of the Research*

The aim of the study is to assess the ecological effects of the economic and technical aspects of steel halls in the process of their reuse. Conditions for multi-criteria environmental assessment have been introduced for the structure of hall-type buildings that are demolished and reassembled. Based on the generalized analysis [31], cumulative energy and material indicators were derived as total Qi and partial cost equivalents (UK, UE) in three life phases: construction, demolition and reuse of hall buildings. The full life cycle assessment of steel halls (LCA) is based on methodological assumptions that enable the monitoring of the ecological effects of multiple-assembly buildings. Computational research models are the frame structures of steel halls [50]. The essence of the research is to reuse the existing building elements without the need to incur energy expenditure for their re-production. This approach is in line with the principles of the circular economy (CE) [39,40].

#### *2.2. The Course of EET Assessment in LCA Methodology*

The research was limited to analyzing the skeleton of steel halls subjected to the process of multiple assembly. A choice analysis (CA) of the most optimal ecological solution for steel halls was proposed according to the multi-criteria economic, ecological and technical assessment (EET) of cumulative indicators, taking into account the LCA methodological assumptions:

Stage I (defining the purpose and scope)—the purpose specified in point 2.1. The adopted methodological scope of EET:

Ecological—consisting of determining the ecological effects of a building object on the environment, included in the production processes of construction, use and demolition.

Technical—consisting of determining the optimal, with regard to the adopted ecological and economic criteria, technical variant of a building object or its part, e.g., construction, demonstrating the acceptable limits of discrepancy for the adopted optimal architectural and construction solution, resulting from insufficient consideration of ecological parameters.

Economical—consisting of determining the cost expenditure generated by the optimal variant of a multiple-assembly facility for the adopted technical and ecological assumptions.

The method proposed by the authors will make it possible to carry out an integrated indicative ETE assessment, taking into account the building's depreciation path and indicating the ecological profits that can be generated by hall-type buildings. Ecological depreciation is the reimbursement of the environmental costs incurred in constructing a building at LCA. The measure is the number of times the elements of the structure, housing or equipment are used.

Stage II (LCIA—life cycle inventory analysis):

Within the boundaries of the system, the flows of all materials, energy carriers and construction works used in the construction, use and demolition process were calculated based on the design assumptions of the steel hall models. Ecological costs were estimated for each of these flows.

Cycle I—creation and operation of the construction and operation of the building structure (hall design, cost estimates for selected model assumptions) determines the cumulative cost (QI ) as the equivalent of all energy L/E (labor, equipment) and material processes *M* of the first assembly of the MASH structure.

Cycle II—another assembly (reconstruction or demolition project and erection of a new hall in a different place using the existing hall superstructure) determines the cumulative cost (QII) as the equivalent of all *L/E* and material *M* energy processes necessary for the second assembly of the MASH structure.

In the second phase of the hall structure's life, the following options are possible:

Option 1: change of function, but the superstructure of the hall remains in the same place; only the structure and the casing are renovated.

Option 2: change of function but the superstructure completely or partially dismantled and relocated while the foundations remain.

Option 3: the foundations and the superstructure of the hall are dismantled and moved to another location with the need for renovation.

This study focuses on option number 3.

Stage III (LCIA—life cycle impact assessment)—aggregation of data from cycle I and II of MASH life, presents the division of QI,II cumulative total costs into partial ones as pro-environmental UE and environmentally degrading factors, UK. In the second phase of assembly (II life cycle), the accumulated energy is transferred to the next structure without the need to incur environmental and energy expenditures for the production of new steel elements. It was assumed that the ecological cost effectiveness contained in the repeated use of the main structure of the building translates indirectly into the reduction of the effects of environmental impacts resulting from the inventory of impacts in the LCA method.

Stage IV (LCI—life cycle interpretation) ecological assessment of the adopted structural solutions for multi-assembly steel halls (MASH). The research focused on the comparative analysis from stages II and III as an interpretation of the basic assessment of the environmental impacts of steel structure hall facilities.

Stage V Conclusions, summary, recommendations.

The idea of the method is in line with the development policy of the European Union [46] contained in "The European Green Deal" will transform the EU into a modern, resource-efficient and competitive economy, ensuring:


#### *2.3. Main Criteria of the Ecological Evaluation of MASH*

The criteria adopted for the EET assessment belong to stage II of LCA and result from the preparation of investment projects in the construction industry, starting from technical and economic assumptions, through the construction design and ending with implementation. Thus, the criteria represent the full life cycle of objects; they are divided into:

Location criteria: this refers to the necessity to adapt the functions of the areas for development to the natural conditions and not the other way around. The analysis shows the compensation indicators for the lost biologically active surface.

Criteria for the selection of design solutions: selection of the optimal static and material variant of the hall, enabling its disassembly and reassembly.

Cumulative design ETE criteria: determines the cumulative ecological and economic costs of the energy contained in work, equipment and materials for the primary and secondary MASH design.

Performance technology criteria related to the assembly and disassembly of the structure: It constitutes the share of the involved work of equipment, labor and auxiliary materi-

als for the modern conditions of the investment implementation, e.g., Just in Time [47]. Reusability criteria: is the basis for a comparative analysis after the first period of operation. The analysis presents indicators that express the amount of energy and mass of

structural elements to be reused, as well as material and energy treated as waste [34]. The aforementioned criteria create an interdependent chain of connections in the

eco-industrial system (the sum of technological processes, energy and materials, starting from the construction of the object, demolition to subsequent use) [51]. This should be understood as a balancing system of inputs and outputs, the flow of energy and matter between the environment and the industrial system [51,52].

EU regulations apply to the selection of a work contractor or tenants of buildings, taking into account non-price criteria relating to environmental aspects [53].

#### **3. Subject of the Research, Basic Assumptions**

*3.1. Stage I (Defining the Purpose and Scope)*

The design and material assumptions in Sections 2.1 and 2.2 apply to selected model steel structures to test the EET method. Four static schemes of typical halls found in the investment market were adopted. The LCA path was analyzed on single-span structures in modular span variants ranging from 12.0 m to 48.0 m.
