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‍1. Energetic Retrofits

There are several strategies to reduce the built environment’s CO2 footprint; using lower-carbon materials, building less, and optimising existing buildings, to name only three. To the latter category belongs retrofitting.

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Energetic retrofits are used to reduce the operational carbon emissions and improve the energy efficiency of existing buildings. These retrofits, which include better performing envelopes and more balanced energy mixes, are essential to reach the industry’s climate goals, and are the object of an increasing number of regulations Europe-wide. 

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However, achieving these targets is not without its challenges. Retrofits must balance the gains from the operational carbon savings with the embodied carbon emissions from construction materials or they won’t be truly effective. 

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A recent whitepaper by the Austrian Institut für Immobilienökonomie has explored in depth different retrofitting strategies and how to balance these two aspects.

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2. Embodied vs. Operational Carbon Emissions

Energetic retrofits can offer a dual benefit to both reduce operational carbon emissions —  by lowering energy consumption — and also have the potential to address the sector's embodied carbon footprint. 

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As it stands, typical energy retrofits are projected to release 30–40 gigatons of CO2e by 2050, underscoring the magnitude of the challenge ahead. However, with smart refurbishments utilising low-carbon solutions, there is a substantial opportunity to mitigate these emissions significantly.

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Since a large portion of the retrofits concerns insulation, bio-based solutions such as panels made from eelgrass, mycelium, or straw, could really steer the industry towards better materials.

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Yet, a notable gap remains in understanding the trade-off between embodied and operational carbon emissions. The data on embodied carbon in retrofits is limited, making it difficult to fully understand and mitigate its impact. 

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3. Benchmarks

Various organisations have established guidelines for embodied carbon values, focusing mostly on new construction projects. For example, LETI's Climate Emergency Design Guide suggests target values below 350 kg CO2e/m2 for non-residential buildings and below 300 kg CO2e/m2 for residential buildings, considered as benchmarks for low-carbon construction. 

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However, average current values reported by sources like Ramboll and Hines range significantly higher, indicating a gap between existing practices and best-in-class targets.

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The accuracy in predicting embodied emissions and associated costs varies, with the assessment of lifecycle impacts presenting more complexity. Evaluating the impact of energy-related retrofits involves numerous factors, including the scope, timing, and specific nature of the retrofit measures. A comprehensive approach must consider the decarbonisation potential of building materials over time and the regional and functional diversity of buildings, as climate conditions and material choices significantly influence the ecological payback of construction projects. 

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Tailored strategies are essential for minimising embodied carbon across different regions and building types, which means that what the industry needs more than ever are targeted approaches and localised regulatory frameworks fit to address the unique challenges and opportunities that arise.

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4. Regulatory Frameworks

The regulatory landscape surrounding the real estate and construction sector is rapidly evolving to address the urgent need for carbon reduction. New carbon policies are emerging ever more often, setting carbon limits and requiring transparency backed by data. Nordic countries such as Denmark and Sweden often lead the way, but Europe-wide measures are gradually coming into action. 

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However, a discrepancy still exists between stakeholder perception and market practice, particularly concerning the collection of ecological payback data from retrofits. While the importance of data collection on ecological payback is widely acknowledged, actual market practices often fall short, with relevant data not being systematically recorded. 

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The tightening regulatory framework serves as both a challenge and an opportunity for the sector. All stakeholders will need to adapt to the new regulations and standards, but it also offers the opportunity to leave aside secrecy and promote cross-sector collaboration. Only by collaboratively improving data collection and transparency, can the sector make significant progress towards reducing its carbon footprint.

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5. Strategies for Optimising Retrofits

The report highlights a detailed strategic approach to optimising retrofits. It involves a 5-step methodology focusing on balancing embodied carbon against operational savings, with a strong emphasis on selecting low-carbon and bio-based materials to minimise emissions. 

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The strategies for optimising retrofits include:

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01. Ecological Performance Assessment: Begin with a comprehensive assessment of the building's current ecological footprint, focusing on both operational and embodied carbon emissions. This assessment serves as the baseline for measuring improvements and guiding retrofit decisions.

02. Material Selection: Prioritise the use of low-carbon materials in retrofit projects. This involves exploring alternatives to traditional, high-emission materials and considering the life cycle emissions of materials chosen for the retrofit.

03. Retrofit Scope Optimisation: Determine the scope of the retrofit based on the building's needs and the potential for carbon savings. This can range from light touch-ups to deep retrofits, with the intensity of intervention carefully matched to both environmental impact and investment considerations.

04. Implementation of Energy-Efficient Systems: Upgrade building systems to enhance energy efficiency, focusing on heating, ventilation, air conditioning, and lighting systems. The selection of systems should prioritise energy savings and reduced operational emissions.

05. Monitoring and Verification: Establish a system for ongoing monitoring and verification of retrofit outcomes. This ensures that the projected carbon savings are realised and provides data for continuous improvement.

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By following these strategies, we can significantly reduce the carbon footprint of retrofit projects, balancing the immediate benefits of operational carbon savings with the long-term goal of reducing embodied carbon emissions.

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6. Data Collection for Embodied Carbon Assessment

Accurate data collection on the embodied carbon of materials used in energetic retrofits is crucial for assessing their environmental impact. This process involves leveraging databases and tools that offer benchmarks for the environmental impact of construction materials, as well as utilising Environmental Product Declarations (EPDs) for precise carbon footprint quantification. 

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The challenges and solutions include:

- Utilising Databases and Tools: Access to commercial and governmental databases provides essential benchmarks for evaluating the environmental impact of construction materials. Our platform gathers and enriches material data from      thousands of different materials, with a heavy focus on bio-based and innovative low-carbon solutions.‍

- Employing Environmental Product Declarations (EPDs): EPDs are instrumental in quantifying the carbon footprint of materials, offering verified data on environmental performance from a life cycle perspective. 

- Utilising Life Cycle Assessments (LCAs): Life Cycle Assessments are an essential (and often required) tool to assess the impact of a project. They take into account different portions of the life cycle of a product, from extraction to      disposal.

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7. Conclusion

As the sector moves forward, a collaborative approach among stakeholders — including asset owners, investors, construction companies, material providers, and policymakers — is essential. Such collaboration can foster the development of standardised practices for data collection, analysis, and reporting, facilitating the widespread adoption of low-carbon retrofit solutions. 

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The conclusion of this discussion is clear: by committing to a holistic approach that balances operational and embodied carbon considerations, the sector can make a significant effort to combat climate change. The time for action is now, with the need for strategic, informed, and collaborative decisions more pressing than ever.

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