# Ecological and Economic Assessment of the Reuse of Steel Halls in Terms of LCA
## 2 Purpose, Assumptions and Research Method
### 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. Figure 1: The methodological framework of the presented scientific approach to determining ecological and economic benefits. 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 (Q\({}^{\text{I}}\)) 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 (Q\({}^{\text{II}}\)) 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 Q\({}_{\text{I,II}}\) 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.