Empowering the Building Sector: Adopting stricter Life Cycle Assessment (LCA) requirements is crucial for a sustainable future, driven by Holistic Systems Thinking

“The application of stricter LCA requirements in building projects presents multifaceted challenges that entail adopting more holistic and multidisciplinary approaches, a perspective that acknowledges the intricate interplay of factors influencing the building sector's response to evolving climate requirements”, writes Aliakbar Kamari , Associate Professor of Building Science and the coordinator of master’s level course “Design-integrated Life Cycle Assessment” at the Department of Civil and Architectural Engineering, Aarhus University.

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LCA calculations have been mandated for new construction projects in Denmark as of January 1, 2023. Effective July 1, 2025, a significantly more stringent threshold for LCA requirements will be instituted, with the carbon limit decreasing from 12 kg CO₂eq/m²/year in 2023 to a maximum carbon footprint of 8 for Institutions, 7,5 for Apartment Buildings, and 6,7 for Single-family Homes. This limit is expected to be further reduced substantially between 2025 and 2029, contingent upon the type and size of buildings (1). Comparable national regulations or regulatory measures have been implemented in recent years across several other EU member states, including Finland, France, the Netherlands, Norway, Sweden, and the United Kingdom.

In light of the significance of such climate agreements, a range of critical inquiries emerge regarding their implications for various stakeholders in the building sector, including architects, engineers, contractors, property owners, municipalities, and end-users.

Questions arise: What are the tangible consequences of these agreements for each of these groups, and more importantly, how does this impact the quality of the final product (i.e., the finished building)? What challenges does the industry anticipate in adapting to new regulatory frameworks and environmental mandates? Additionally, what strategies can be implemented to facilitate a swift and effective transition towards sustainable practices?

Addressing these inquiries comprehensively entails adopting more holistic approaches(2), a perspective that acknowledges the intricate interplay of factors influencing the building sector's response to evolving climate requirements. Critical dimensions of this discourse using a systems thinking framework (3) encompass the dimensions of People, Product, Process, Policy, and Technology (i.e., 4P+T strands (4)), providing a systematic approach to understanding the industry's multifaceted challenges in this context.

People (project stakeholders)
While calculating and reporting a building's environmental impact is mandated, design stakeholders, such as architects and engineers, encounter substantial obstacles in adapting their projects to these new regulatory requirements. A significant factor contributing to this challenge is the prevalent lack of foundational knowledge and prior experience in LCA among these professionals. Additionally, there exists a general deficiency in awareness and required expertise regarding the critical importance of embodied carbon reduction (as opposed to operational carbon). This knowledge gap can hinder the adoption and implementation of innovative and practical solutions to minimise environmental impacts. A notable disconnect often exists among architects, engineers, and builders regarding their respective priorities. While certain stakeholders may emphasise aesthetics or performance, others may prioritise sustainability, leading to conflicts in the decision-making process (5).

Process (design, construction, renovation, and demolition)
Developing building projects to achieve better sustainability outcomes is a very complex task, after all. The root of this complexity is related to the sector's fragmented nature due to multi-stakeholder, multi-objective, geographical/climate/time-sensitive, and the overall wicked nature of the problem at hand. Contrary to the more conventional linear approach, hybrid top-down and bottom-up approaches are required to balance holistic and reductionist thinking to cope with the multifaceted complexity. Consequently, there is an imperative for more integrated, adaptive, evolutionary and dynamic processes that incorporate iterative feedback loops, provide a systematic structure for the design, construction, and renovation, and importantly, manage the end-of-life cycle in a sustainable manner. In doing so, decision-making during the early design stages, including facilitating the process from end-of-life deconstruction to early-stage building design and renovation, has to be prioritised that will enable circular models and scenarios such as upcycling/reusing/downcycling materials, disassembly possibilities for the structure or enclosure, adaptability scenarios, etc.

Product (sustainable high-performance buildings)
A vertical view of sustainability is achieved through a whole-life-cycle approach (i.e., product, construction, use, and end-of-life stages), which can help fulfil stricter LCA requirements and effectively reduce the carbon footprint of building projects. The embodied carbon generated by traditional construction methods should be managed by adopting uncomplicated solutions, such as the UNEP-backed three-pronged solution: avoid, shift and improve to ensure emissions are slashed. Moreover, a simultaneous horizontal view of sustainability aspects should be prioritised to ensure building projects with regard to their types and functions meet broader objectives, e.g., in terms of social and economic aspects. Design decisions should be adopted that positively contribute to improving energy efficiency and indoor climate, as well as the health and well-being of the occupants. Nevertheless, time constraints and budget considerations can potentially push stakeholders to prioritise immediate project needs over sustainability. For example, the availability and pricing of low-carbon materials can pose challenges; many sustainable alternatives remain relatively costly or less accessible in specific geographical regions.

Policy (building codes, regulatory requirements and mandates)
While implementing and enforcing new regulations represent a critical milestone in sustainable building practices, the effectiveness of these regulations necessitates an ongoing process of monitoring, (re)assessment, and refinement. Concerns about potential negative findings and fear of greenwashing significantly hinder embracing sustainability-focused decisions. As the building sector continues to evolve and gain insights into quantifying environmental impacts, it can enhance its commitment to reducing its ecological footprint through a more comprehensive framework while promoting ecological resilience and integrity. A holistic approach to carbon management should move beyond attributional models to include the consequential impact of a decision (i.e., Attributional vs. Consequential LCA), and incorporate dynamic methods to account for changes over time (i.e., Dynamic vs Static LCA) as well as broader ecological considerations, such as biodiversity (both on-site and off-site) and land use and land changes. By expanding our focus beyond carbon emissions alone (known as moving beyond "carbon tunnel vision"), more informed decisions can be made that reflect the interconnectedness of construction practices and their long-term implications for environmental sustainability.

Technology (digital tools and decision-support systems)
The complexity of assessing comprehensive lifecycle data and the high initial costs of tools and software can deter construction companies from adopting LCA practices. Obtaining reliable data and EPDs for various materials poses a significant challenge, as inconsistencies in data formats and the limited availability of localised environmental information complicate assessments. Developing and adopting the right IT-supported digital tools and decision-support systems can significantly contribute to these issues. To enhance early design processes, there is general agreement among researchers and practitioners on creating novel BIM-based (Building Information Modeling) software tools (6) integrated into material databanks and LCA databases. These tools aim to facilitate design decisions, manage information, and conduct automated analyses to meet the specific needs of current practices in designing new buildings and renovating existing ones. BIM enables designers to assess and compare design scenarios in the early stages (responding to the typical lack of data) and promotes efficiency during the whole building life cycle, enabling automatic updates and providing essential data, such as material quantities, thereby influencing decisions that can significantly impact the building's life cycle. The outcome will streamline communication, collaboration, and cohesion among stakeholders, enabling effective and optimal sustainable design alternatives within a shorter timeframe and enhancing the likelihood of meeting the project objectives.

“By employing holistic frameworks, we can better understand the interconnectedness of various elements and identify actionable pathways to empower stakeholders to navigate the transition to sustainable construction, aligning with new carbon requirements as well as ensuring cost-efficient, affordable, inspiring, safe, and attractive building projects that perform well for decades, promote healthier living conditions, and contribute positively to community well-being”, concludes Aliakbar Kamari.

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Follow Aliakbar's research, particularly in relation to the numerous pertinent ongoing PhD and Master's thesis projects he oversees in the following areas:

• Streamlining BIM-integrated LCA for rapid-iterative-informed-early stage upfront carbon assessment by architects and engineers,
• Quantitative Environmental Life Cycle Assessment of Socially Oriented Design Intents,
• Quantification of Biodiversity Loss in Building Life Cycle Assessment,
• Life cycle assessment of Building Renovation vs New Construction Projects in Denmark,
• Investigation of how methodological differences in current PCRs affect EPD results, and
• Assessing the future environmental consequences of the Danish construction sector through dynamic material inventories and scenario-based LCA.