Low-Carbon Design for Meeting London Energy Transformation Initiative (LETI) 2030 Requirements

Session: Track G: Minimizing Impact: Towards Net Zero Density

Alex Black-RobertsDiego PhilippsProject image

Alex Black-Roberts
Associate Structural Engineer, WSP

Diego Philipps
Technical Director and Net Zero Lead, Building Structures, WSP

In the context of the climate emergency, upfront carbon is becoming one of the most important design parameters. In the UK, the London Energy Transformation Initiative (LETI) has proposed 2030 targets for upfront carbon to put buildings in the path towards net zero. These are: 300 kg CO2e/m2 for residential buildings and 350 kg CO2e/m2 for commercial, representing a reduction of more than 70 percent from the current industry averages. To achieve such reductions, we must make fundamental changes to the way we design tall buildings.

Tall buildings can be very carbon-intensive. This presentation covers a parametric study of different types of buildings and materials, varying height, area, spans, basements, material specifications and other key parameters, to show how to achieve the proposed targets. The study is conducted in the context of the UK, including the results from WSP’s internal benchmarking studies in 2020 and 2021.

It highlights the relationship between height and carbon emissions and underscores the importance of intentionally designing geometries, such as spans, to reduce carbon emissions. It includes a parametric study of multiple stability systems, and it examines the paradigms we need to change in our search for lower-carbon buildings. Finally, it explores the impact of specifying lower-carbon materials, such as cross-laminated timber (CLT), alongside the challenges of using cement replacements, lower-carbon concretes and lower-carbon steel.

The presentation is prepared in the context of the UK, including the results from WSP’s internal benchmarking for 2020 and 2021.