Building Life Cycle Assessment (LCA) assesses the environmental impacts of a building throughout its useful life, from the extraction of raw materials for its construction, to its eventual demolition and waste disposal. This has a significant impact on both the environment and long-term costs. Would you like to know more about how this methodology can boost sustainability and reduce the costs of your project? In this article, we will explain it to you!
1. Life Cycle
The life cycle of a product or building refers to the set of stages it goes through from its conception, design, manufacture or construction, use, maintenance, renovation, to the end of its useful life and final disposal.
The life cycle of a product or building can vary depending on its duration and complexity, that is, it depends on several factors, such as the type of material used, the technology involved, the conditions of use and maintenance, among others. Effective management of this cycle is crucial to optimize efficiency, reduce environmental impact, and promote long-term sustainability.
2. What is LCA Life Cycle Assessment?
Life Cycle Assessment (LCA) is a methodology, based on regulations, that allows the environmental impacts of the useful life of a product, material or building to be identified. In the case of LCA in buildings, it allows the environmental impacts generated by the building and its embedded carbon to be assessed.
Embedded carbon, commonly known as a carbon footprint, is generated in the production of a material and throughout its life cycle. Calculating embedded carbon is critical to understanding the total environmental impact of a product or project. By knowing the number of emissions associated throughout their life cycle, informed decisions can be made to reduce those emissions and reduce the contribution to climate change.
Life Cycle Assessment (LCA). Source Evalore.
Do you want to carry out a Life Cycle Assessment (LCA) in your building to boost its sustainability?
The life cycle stages of a construction product and a building, according to the EN standard, applicable to the European Union, are defined in the standards: EN 15804 and EN 15978.
Within the Life Cycle Assessment (LCA) of buildings, we categorize emissions into stages of the complete cycle, denominated by letters from "A" to "D", ranging from the extraction of raw materials to the disposal at the end of the building's useful life. These stages are divided into:
Product stage (A1-A3): involves the phases of material extraction, transport to the manufacture of the product, it is called "cradle-to-door" emissions.
Construction Stage (A4-A5): comprises the transportation of the construction product from the manufacturer (factory gate) to the construction site, the installation of the product in the building, the waste from the installation, and includes the necessary labor and equipment.
Use Stage (B1-B5): During this phase, the construction product is used in the building or project, and its operations and performance over its useful life are evaluated. It covers all maintenance and renovation activities that can be carried out during the useful life of the building or project.
Operational stages (B6-B7): encompasses energy consumption (B6) and water consumption (B7). In some projects this stage is excluded depending on the objective of the analysis. The scope of the project may not include the detailed analysis of the operational stages, especially if the main objective of the LCA is to assess the environmental impact of the construction and demolition stages of the building.
End-of-life stage (C1-C4): covers the impacts associated with the demolition, transport, treatment and final disposal of the building's materials once its useful life has ended.
Benefits stage (D): considers the impacts avoided thanks to the reuse, recycling or recovery of materials at the end of their useful life, accounting for the environmental benefits beyond the building system.
The cradle-to-grave emissions are stages A, B, and C together; The entire cycle, including stage D, is known as cradle-to-cradle emissions.
By following these stages, the environmental and economic impact of a construction or building product can be calculated from its extraction to its disposal, allowing informed decisions to be made in the choice of more sustainable materials and construction methods.
Source: One Click LCA. Image edited by Evalore.
4. Phases of a stroke
A building's life cycle assessment (LCA) consists of several interrelated phases that assess the environmental impact of all stages of the building's life cycle, from raw material extraction to construction, use, maintenance, and eventual demolition or recycling. These phases typically include:
Objective and scope: it consists of defining the specific objectives and the stages of the life cycle considered.
Inventory analysis: in this phase, data about the building must be collected, such as its design, construction materials and measurements, energy consumption, water use, and waste management.
Environmental impact assessment: based on the analysis of preliminary results.
Interpretation: this is the final phase, where opportunities for improvement are identified.
LCA Phases. Source: ISO 14040.
The phases of an LCA are carried out in an iterative manner, they can vary in detail depending on the specific context of the life cycle assessment and the objectives of the project. The ultimate goal of a building's LCA is to identify opportunities to reduce environmental impact throughout its life cycle and promote the construction of more sustainable and environmentally friendly buildings.
5. Environmental impact categories assessed by LCA
The environmental impact categories assessed by Life Cycle Assessment (LCA) are specific aspects of the environment that can be affected by a product, process or service throughout its life cycle. LCA uses indicators and models to quantify and compare these impacts, providing a comprehensive understanding of the environmental effects associated with a specific activity and enabling informed decisions to improve sustainability. Some of them are the following:
Global warming potential (greenhouse gases), kg CO2e: describes how much a product contributes to climate change.
Acidification of land and water sources (kg SO2): describes how much a product acidifies the environment (acid rain).
Eutrophication (kg N or kg PO4e): describes the exaggerated flow of nutrients between ecosystems (algae growth).
Ozone depletion (kg CFC-11): describes the damage caused to the ozone layer in the stratosphere.
Tropospheric ozone (kg NOx, kg O3 eq or kg ethene): describes the amount of smog caused by the gases emitted.
Depletion of non-renewable energy resources (expressed in megajoules MJ): measures the amount of non-renewable energy consumed during all stages of the life cycle of a product, process or service, including fossil fuels such as oil, natural gas and coal.
Environmental impact categories in LCA. Source: Evalore.
In buildings, most of the environmental impacts come from the product stage (A1-A3), i.e. from the carbon embedded in construction materials. The amount of these impacts is declared in a standardized document called the Environmental Product Declaration (EPD), which includes the results of a product's life cycle analysis.
6. Tools and Methods
Life cycle analysis is performed through various tools and methods, including Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA). The first focuses on the environmental impact, while the second analyzes the economic costs of the project.
At Evalore, we recommend the use of dedicated Life Cycle Assessment (LCA) software, as it enables accurate comparisons between different design options or materials, automates calculations, and provides results aligned with the main applicable standards (EN 15804 and EN 15978). These tools also facilitate integration with BIM models and the generation of reports compatible with building environmental certification schemes such as LEED and BREEAM, as well as the Level(s) assessment framework. However, the analysis can also be carried out manually using environmental impact factors per material type obtained from recognized databases or verified EPDs, thereby ensuring the traceability and consistency of the results.
It is important to note that the selection of LCA software should be based on the specific needs of the project, as well as on the compatibility and requirements of the relevant sustainability certifications. One of the specialized LCA platforms is One Click LCA, it provides a complete view of the environmental impact of projects, offers access to an extensive lifecycle inventory database that includes information on building materials, energy, transportation, maintenance and end of life. In addition, it provides calculation tools for LCA aligned with internationally recognized environmental certification schemes such as LEED and BREEAM, as well as the Level(s) assessment framework, helping projects meet the requirements of sustainable building certifications and standards.
The following graph shows the results, in numerical values (kg), of a LCA life cycle analysis of a building project that has an area of 2,929.45 m2. According to the materials used in construction, the environmental impacts are quantified.
Source: One Click LCA. Image edited by Evalore.
Using the One Click tool, graphs can be viewed and downloaded with percentages of the carbon embedded in the materials according to their classification and the stage of the cycle to which they belong, for example: foundations, structures and facades, beams, slabs and roofs.
Source: One Click LCA. Image edited by Evalore.
7. Sustainability and LCA certifications
The main building sustainability certifications such as LEED, BREEAM, among others, consider LCA as a tool in their evaluation requirements. Likewise, the Level(s) assessment framework incorporates life cycle assessment as one of its main tools for evaluating the environmental impact of buildings. However, the life cycle scope and the types of environmental impacts to be assessed vary between certification schemes and the assessment framework.
According to LEED v4 specifications, the following items are excluded from the analysis: electrical and mechanical equipment and controls, plumbing fixtures, fire detection and alarm system fixtures, elevators and transportation systems, excavations and other site developments, and parking lots. Adding them will not provide any additional credit.
While for BREEAM, the scope of the LCA must include the following elements: façades, windows and exterior skylights, interior pavements, upper floor slabs, ground floor slabs, vertical interior partitions and party walls, and roofs. Unlike LEED, the more building elements included in the assessment, the higher the percentage of points achieved.
In the case of Level(s), the minimum scope of the construction elements must include: foundations, load-bearing structural frame, slab, interior walls, partitions, stairs, facades, roof and parking.
If we analyze the environmental impact categories assessed by the two certification schemes, LEED and BREEAM, it can be observed that the Level(s) framework covers a broader range of categories compared to LEED and BREEAM, including the abiotic depletion potential of both fossil and non-fossil resources.
Environmental impact categories assessed in the LCA. Source: Evalore.
8. Advantages of Life Cycle Assessment
LCA provides the necessary basis for making informed decisions about material selection, contributing significantly to the reduction of environmental impacts such as greenhouse gas emissions, resource consumption and waste generation. It also analyzes economic aspects, including operating costs, maintenance, renovation and demolition, through Life Cycle Cost Analysis (LCC).
Extension of the useful life of the building, by using adaptable and durable materials, as well as considering maintenance.
Optimization of the design of the project and reduction of resource consumption, LCA makes it possible to identify the life cycle stages with the greatest environmental impacts and to propose solutions to reduce them. It also enables comparisons between design options—for example, selecting an optimal thermal insulation for the building can significantly reduce energy consumption. Likewise, comparisons between structural systems can help reduce the overall volume of materials required.
Would you like to take advantage of a LCA Life Cycle Assessment in your construction?
By assessing the environmental impact of a project from conception to demolition, LCA allows us to make informed decisions that minimize our impact on the environment and promote a more sustainable future. Implementing LCA not only benefits the environment, but can also lead to greater energy efficiency, long-term cost savings, and improved occupant well-being.
Find out how this methodology can take your construction projects to the next level in sustainability and efficiency.Contact us to learn more!
Laura Barrios Mogollón Architect and Sustainability Consultant, Espacios Evalore SLP
Building Life Cycle Assessment (LCA) assesses the environmental impacts of a building throughout its useful life, from the extraction of raw materials for its construction, to its eventual demolition and waste disposal. This has a significant impact on both the environment and long-term costs. Would you like to know more about how this methodology can boost sustainability and reduce the costs of your project? In this article, we will explain it to you!
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