Construction projects shape our built environment in both urban and non-urban environments. Every building constructed has a profound environmental implication, and making informed decisions on how they are built, maintained, and eventually decommissioned is essential to reducing their carbon footprint.
LCA systematically evaluates the environmental aspects associated with a product, process, or activity from its inception to its end of life. In architecture and the construction industry, LCA is divided into different stages of a building’s life cycle, denoted as stages A, B, C, and D, with each stage encompassing specific phases (A1, A2, etc.) and processes relevant to the stage.
This article aims to explore the different stages and phases, as well as touch on documentation and relevant, foundational European Standards.
.png)
Stage A - Product Stage
Stage A covers all phases before the building’s completion and active use. Phases A1 through A3 cover the manufacture and acquisition of building materials and products necessary for the construction phases, while phases A4 and A5 cover the actual construction process, starting with the transportation of ready-for-use materials.
A1 - Raw Material Extraction
The first phase involves the extraction of raw materials essential for construction. This includes minerals, metals, and other resources necessary for the manufacture of building materials. This phase evaluates the environmental impact of extracting raw materials from the Earth, considering factors such as energy consumption, habitat disruption, and resource depletion.
A2 - Transportation of raw materials
A2 considers the transportation of the extracted raw materials from their source to manufacturing sites. The mode of transportation, distance traveled, and fuel efficiency are central factors that directly influence the overall environmental footprint of this phase.
A3 - Manufacturing
The manufacturing phase assesses the transformation of raw materials into construction materials and products. This includes processes such as refining, shaping, and assembling materials to create the final product. Environmental factors in this phase include energy consumption, emissions, waste generation, and the use of chemicals.
A4 - Transportation of manufactured products
This phase accounts for the transportation of the manufactured materials and products to the construction site. This includes everything from concrete, steel beams, and prefabs to furniture and decorations for the building’s interior environment. Similar to A2, mode of transportation, distance, and fuel efficiency are major factors in calculating the total environmental footprint of this phase.
A5 - The construction phase
The Construction phase (A5) encompasses the actual assembly of construction products into the final structure. This involves the work of architects, builders, and other construction professionals. The environmental impact during this phase includes energy consumption, emissions from construction activities, and waste generation associated with on-site processes.
STAY IN THE KNOW!
Sign up for our newsletter to receive invitations to events, notification of new content and other LCA insights.
Stage B - Use Stage
The Use Stage is a critical phase in the life cycle of a construction project, where the building is operational and in active use. It involves a multitude of activities and considerations that contribute to the overall environmental impact, spread over 7 phases - B1 through B7. Integrating sustainable practices in these phases contributes to a more environmentally responsible and resilient built environment.
B1 - Use or application of the installed product
The B1 stage covers the operational use of the installed product. Key considerations in this stage include performance in intended function, user behavior, occupancy factors and environmental impact mitigation measures. These considerations cover usage patterns by the occupants (such as adjusting heating or cooling), the efficiency of appliances, insulation and overall functionality of building systems.
B2 - Maintenance
Maintenance encompasses activities performed to keep the building in good condition throughout its operational life. Regular maintenance can prolong the life of building components, reducing the need for replacements and the associated environmental impacts of facilitating those replacements. Efficient and mindful maintenance practices contribute to the sustainability of the building.
B3 - Repair
Repair involves addressing specific issues or damages to building elements. Repair activities can be more sustainable than complete replacements, as they often require fewer resources and generate less waste. Assessing the environmental impact of repair activities is crucial for making informed decisions during the Use Stage.
B4 - Replacement
The replacement phase considers larger-scale modifications or upgrades to the building. This includes substantial changes that aim to improve functionality, aesthetics, or compliance with updated standards. It also applies for replacements made where repairs are impossible or insufficient in order to remain compliant with safety or other relevant standards. Evaluating the environmental impact of renovations helps identify opportunities for sustainable design and construction practices.
B5 - Refurbishment
Refurbishment involves adjusting the building to meet evolving needs or regulations. This may include changes in occupancy, technology, or safety standards. It can also involve expansion of the structure with new floors, wings or extensions. Assessing the environmental impact of refurbishment ensures that modifications align with sustainability goals and minimize resource use.
B6 - Operational Energy Consumption
B6 focuses on the operational energy consumption of the building. This phase assesses the energy required for heating, cooling, lighting, and other functions during the building's use. Understanding and optimizing operational energy consumption is crucial to reduce the carbon footprint associated with ongoing energy expenditure.
B7 - Operational water use
B7 tackles all water usage in the building, from tap water to water use in appliances and any installed systems that involve water in its operation.
Stage C - End of Life Stage
The End of Life Stage delves into the phases after a building's useful life. This stage sheds light on the sustainable disposal and recycling practices that contribute to reducing the overall environmental impact. The stage encompasses phases C1 through C4 and emphasizes the responsible management of materials and waste generated by the decommissioning and demolition of a building.
C1 - Demolition
Demolition is the systematic dismantling of the building structure. This phase includes the removal of materials and components, requiring careful planning to manage waste streams effectively. Sustainable demolition practices aim to recover valuable materials for reuse or recycling while minimizing the generation of waste sent to landfills.
C2 - Transportation of Demolition Waste
Transportation of demolition waste is a critical consideration of the End of Life stage. Efficient logistics and transportation methods can reduce the carbon footprint associated with moving waste materials. Additionally, careful planning can facilitate the separation of materials for recycling or proper disposal, reducing both impact and required labor in stages C3 and C4.
C3 - Recycling or Disposal
Recycling or disposal involves the treatment of materials removed during demolition. Sustainable practices prioritize recycling over disposal, aiming to reuse as much material in new construction projects as possible. This phase also assesses the environmental impact of recycling processes and the potential benefits of diverting materials from landfills.
C4 - Final Disposal
The final disposal phase addresses the remaining materials that are not suitable for recycling. Proper disposal methods, such as landfilling or incineration, are considered with a focus on minimizing adverse environmental effects. Sustainable disposal practices aim to reduce the environmental impact associated with the disposal of non-recyclable materials.
Stage D - Beyond End of Life
Stage D delves into the considerations beyond the anticipated life cycle of a construction project. It extends the assessment to encompass long-term impacts, disposal of materials, and potential environmental effects. Beyond End of Life is about monitoring long-term effects on the environment, and the net benefits of reusing recovered and recycled materials in new projects, as well as exploring new concepts and opportunities for reuse, reclamation, and recycling. Stage D currently remains mostly on research level, and the subphases haven’t yet been conclusively set.
What is Environmental Product Declaration (EPD)
An integral part of the LCA process is the Environmental Product Declaration (EPD). This documentation provides transparent and comparable information about the environmental performance of a product or construction project. Based on LCA principles, EPDs cover various stages of a product's life cycle. The purpose of EPD documentation is to empower stakeholders to make informed decisions, fostering a culture of sustainability in the construction industry.
European Standards (EN 15978 and EN 15804)
In Europe, standards such as EN 15978 and EN 15804 define the life cycle stages for construction projects. These standards offer a structured framework for assessing and reporting the environmental performance of buildings.
In unison, the standards form the basis, requirements, and processes that LCA adheres to, from the outlining and definition of each stage to the stipulation of requirements for data quality and documentation for all projects undertaken.
By adhering to these standards, the construction industry in Europe aims to enhance transparency and comparability in environmental assessments, and foster sustainable practices and more environmentally conscious decision-making in the construction industry.
The Stages of LCA is a Methodology for Sustainability
The stages of Life Cycle Assessment provide architects and construction professionals with a robust framework for evaluating and addressing the environmental impact of construction projects. By considering every link in the vast economic chain required to construct, maintain, and decommission a building, stakeholders can make informed decisions that minimize the ecological footprint of their projects. As we continue to build the structures we need, understanding the entire life cycle of every building is essential for the construction industry to do its part in ensuring a greener and more sustainable future.
