In the quest for a sustainable future, the built environment plays a crucial role. As the world grapples with the urgent need to address climate change, initiatives like the London Energy Transformation Initiative (LETI) have emerged to drive the transition towards a zero-carbon future. LETI, a voluntary network of over 1,000 built environment professionals, is at the forefront of this movement, aiming to understand and clarify the path to a zero-carbon built environment in the UK.

In this comprehensive guide, we will explore LETI’s groundbreaking work on embodied carbon reduction strategies and calculations. Embodied carbon refers to the carbon emissions associated with the entire lifecycle of a building, including construction, operation, and demolition. By focusing on reducing embodied carbon, we can make significant strides towards achieving a sustainable and low-carbon future.

The Need for Embodied Carbon Reduction

The construction industry has long been a significant contributor to carbon emissions. While much attention has been given to operational carbon emissions, embodied carbon often remains overlooked. However, as the urgency to combat climate change deepens, it is essential to address the carbon footprint of the built environment comprehensively.

LETI recognized this critical gap in knowledge and developed the Embodied Carbon Primer as supplementary guidance to their Climate Emergency Design Guide. This primer aims to equip architects, engineers, interior designers, and urban designers with practical tools and best practices to reduce embodied carbon in building design.

Understanding the Embodied Carbon Primer

The Embodied Carbon Primer provides a wealth of information and resources for professionals in the construction industry. It offers a clear and accessible overview of embodied carbon reduction strategies and methodologies. By demystifying the language, targets, and calculation methods surrounding embodied carbon, LETI empowers professionals to take concrete actions towards achieving ambitious carbon reduction goals.

Key Elements of the Embodied Carbon Primer

  1. Building Design Guidelines: The Embodied Carbon Primer outlines best practices for reducing upfront emissions associated with construction, maintenance cycles, and future reuse. It provides guidance on material selection, massing, and site treatment to minimize embodied carbon.
  2. Planning Considerations: The document highlights the impact of planning recommendations on embodied carbon. Planners can gain insights into strategies that designers can employ to reduce embodied carbon in building design, promoting a more sustainable built environment.
  3. Collaborative Approach: LETI emphasizes collaboration among various stakeholders, including architects, engineers, contractors, and manufacturers. By working together, the industry can overcome the challenges of reducing embodied carbon and drive meaningful change.
  4. Continuous Improvement: The Embodied Carbon Primer acknowledges that knowledge and understanding in this field are evolving. LETI encourages feedback and welcomes industry professionals to contribute their expertise to refine and improve the guidance over time.

Endorsements and Impact

The Embodied Carbon Primer has garnered significant support and recognition within the industry. Renowned professionals and organizations have praised LETI’s comprehensive approach and the practicality of the guidance provided.

“It’s like the buses: you wait for a conduit to help the industry turn climate rhetoric into action, and two come along at once. LETI’s Climate Emergency Design Guide and Embodied Carbon Primer are easy to use, well put together, effective tools that remove any remaining excuses for not getting on with it.” – Sunand Prasad, Principal at Penoyre & Prasad.

The impact of the Embodied Carbon Primer extends beyond theoretical guidance. LETI is aware of over 30,000 homes and 1,000,000m2 of commercial floor space that are striving to meet LETI’s new build targets. This demonstrates the tangible influence of LETI’s work in driving the adoption of sustainable building practices and carbon reduction strategies.

LETI’s Ongoing Workstreams for Embodied Carbon Reduction

LETI is committed to continually advancing the understanding and implementation of embodied carbon reduction strategies. Building on the success of the Embodied Carbon Primer, LETI has identified five key workstreams for 2020, each focusing on specific aspects of embodied carbon reduction:

1. Whole Life Carbon and Offsetting

This workstream aims to review LETI’s position on whole life carbon, exploring the concept of true zero carbon. It will delve into the possibilities of full circularity of materials and the role of offsetting. The workstream will develop a clear methodology and hierarchy for offsetting methods to ensure a robust approach to achieving net-zero carbon buildings.

2. Specification and Procurement

To bridge the gap between design intent and actual implementation, this workstream focuses on low carbon procurement and specification. By understanding the challenges faced by contractors and manufacturers, LETI aims to develop specifications that enable the delivery of low carbon buildings. Collaboration with manufacturers and contractors is key to driving meaningful change.

3. Top Down Targets

While operational energy usage has well-established metrics aligned with net-zero carbon trajectories, embodied carbon targets often lack the same clarity. This workstream aims to outline a methodology for obtaining a range of embodied carbon targets that align with national carbon budgets. By setting clear targets, LETI aims to provide a roadmap for the industry to achieve sustainable and low-carbon building practices.

4. Circular Economy and Retrofit

The circular economy offers immense potential for reducing embodied carbon. LETI’s workstream on circular economy and retrofit aims to review and develop circular economy principles and targets outlined in the Embodied Carbon Primer. By defining benchmarks for reuse and designing for viable reuse in the future, LETI seeks to create a comprehensive framework for circular economy practices in the built environment.

5. Case Studies

To inspire and educate industry professionals, LETI is curating a collection of case studies that highlight successful embodied carbon reduction projects. These case studies will complement the Embodied Carbon Primer and provide real-world examples of effective carbon reduction strategies. By sharing best practices and lessons learned, LETI aims to foster knowledge exchange and drive further innovation in the industry.


LETI’s Embodied Carbon Primer has emerged as a game-changing resource for the construction industry. By demystifying embodied carbon reduction strategies and calculations, LETI has empowered professionals to make tangible contributions towards a zero-carbon future. The primer, alongside LETI’s ongoing workstreams, serves as a catalyst for change, driving collaboration, innovation, and continuous improvement within the built environment.

As the urgency to combat climate change intensifies, LETI’s initiatives are crucial for ensuring a sustainable and resilient future. By embracing the principles outlined in the Embodied Carbon Primer and actively participating in LETI’s workstreams, industry professionals can play a transformative role in reducing embodied carbon and creating a built environment that aligns with our climate targets.

Together, we can unleash the power of embodied carbon reduction and pave the way towards a truly sustainable and low-carbon future.