Reducing embodied carbon in MEP — why it matters & what you can do about it

Reducing embodied carbon in MEP — why it matters & what you can do about it

Make sense of MEP carbon with CIBSE Technical Director Anastasia Mylona and One Click LCA CEO Panu Pasanen.


First, what is embodied carbon? What is included and what is not?

Embodied carbon encompasses all carbon emissions associated with a building's lifecycle up to the point of its operational use. This includes carbon emissions from materials, their manufacturing, transportation, construction processes, maintenance, eventual demolition, and transportation to waste recycling. Notably, embodied carbon comprises all installed building components, wastage from construction activities, and eventual replacements of MEP (mechanical, electrical, and plumbing) equipment and parts. However, carbon emissions from the operational use of MEP systems, such as energy consumption, are not considered embodied carbon. Additionally, refrigerant leakages during operation contribute to embodied carbon.


Research indicates that MEP carbon contributes from 15% to 50% of embodied carbon in commercial buildings and up to 50% embodied carbon in retrofits over the lifetime of a building. What contributes to this? Is it materials, transportation?

The significant contribution of MEP (mechanical, electrical, and plumbing) carbon emissions to embodied carbon in commercial buildings and retrofits is influenced by three primary factors. First, replacement frequency plays a crucial role, as more frequent replacements of MEP systems result in greater embodied carbon emissions. This includes the disposal of old equipment and the manufacturing, transportation, and installation of new components. 

Second, refrigerants used in MEP systems contribute substantially to embodied carbon, with careful consideration needed in selecting environmentally friendly options to mitigate their impact. Lastly, energy consumption, either from the grid or from additional MEP systems for energy generation, significantly impacts embodied carbon. Oversizing MEP systems due to risk aversion and the reluctance to discuss risks with clients also exacerbate embodied carbon emissions. 

Ultimately, the main drivers of MEP carbon emissions are cooling, heating, and energy generation, highlighting the importance of thoughtful system design and consideration of future scenarios in achieving sustainability goals.

Reducing MEP embodied carbon

MEP systems account for up to 50% of embodied carbon in commercial buildings and retrofits throughout a building's lifetime. Hear from Dr. Anastasia Mylona of CIBSE and Panu Pasanen of One Click LCA on MEP embodied carbon.

Some in the industry are saying that embodied carbon is the next frontier, after operational carbon.  What does this mean?

The shift in focus towards embodied carbon represents a significant evolution in sustainability efforts within the building industry. Historically, the emphasis has been on reducing operational carbon through energy efficiency measures. However, as energy consumption continues to decrease and buildings become more efficient, the proportion of embodied carbon relative to operational carbon increases. 

This shift underscores the critical importance of addressing embodied carbon emissions from both building materials and MEP (mechanical, electrical, and plumbing) equipment. Modern buildings, with their reliance on MEP systems and energy production technologies, contribute substantially to embodied carbon. The concept of embodied carbon as the "next frontier" implies that it has become a key commercial and competitive consideration, with opportunities for differentiation and market advantage. 

As awareness grows and stakeholders seek solutions to reduce embodied carbon, there is a notable shift away from viewing it as purely an academic topic to one that is commercially viable and increasingly understood by industry professionals and clients alike. However, challenges remain in upskilling the industry and aligning stakeholders towards common sustainability goals, as evidenced by personal experiences navigating building regulations and homeowner perceptions.

By now, the audience is likely wondering what are the actual day-to-day things MEP designers can do to reduce MEP carbon. Can you share the top 3-5 actionable steps MEP designers can take to reduce the impact of MEP?

There are several practical steps MEP designers can implement to mitigate MEP carbon emissions. First and foremost is prioritizing passive solutions, such as optimizing building orientation, maximizing natural ventilation, and incorporating effective shading strategies. Passive measures not only offer cost-effective and reliable means of reducing energy demand but also enhance the building's resilience and longevity. 

Second, addressing the refrigerant question is paramount. Choosing low-carbon or natural refrigerants and minimizing refrigerant leakage can significantly reduce the carbon footprint associated with HVAC systems. Additionally, avoiding over-engineering is essential. MEP systems should be accurately sized based on the specific needs of the building and its occupants to minimize material waste and energy consumption. Furthermore, designers should familiarize themselves with the lifecycle impacts of the products they specify, considering factors beyond price alone, such as the origin of materials and embodied carbon. By integrating these strategies into their design approach, MEP designers can play a pivotal role in advancing sustainability goals and reducing the environmental impact of MEP systems.

How One Click LCA can help you reduce MEP whole life carbon

With One Click LCA's MEP Carbon Tool, MEP designers and engineers can efficiently model whole-life carbon for MEP systems using CIBSE TM65 data, ensuring compliance with the MEP 2040 Challenge. By accessing ready-to-use MEP assemblies, generic MEP data, and manufacturer-specific EPDs, users can streamline the process of carbon modeling for MEP projects. You can book a demo here. 

One Click LCA addresses sustainability challenges practically. Handling data-related issues, complexity, workload, and standards fragmentation, One Click LCA streamlines the design process from pre-project phases to specific product choices. By automating EPD creation and verification, it makes high-quality work accessible to professionals at all levels. Together, ECO Platform and One Click LCA contribute to sustainable construction practices.


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