55 and 70 Gracechurch Street

London, United Kingdom

Two new sustainable towers in the heart of London where advanced engineering insights from RWDI meet city requirements for pedestrian comfort and safety.

Located in the heart of London’s Square Mile, a 30-story development at 55 Gracechurch Street and a 33-story tower at 70 Gracechurch Street will create an elevated public access amenity terrace, significantly increase accessible public space at ground level, and open pedestrian through routes. The presence of public spaces for amenity use is a City of London policy, which aims to create a more pleasant urban environment for workers, residents, and visitors. 


  • The Challenge

    Good wind microclimate conditions are necessary for creating outstanding public spaces in urban environments. Adverse wind effects can reduce the quality and usability of outdoor areas, leading to safety concerns in extreme cases.

    Thanks to RWDI’s deep technical capabilities in wind modeling and analysis, the buildings’ designers approached us to help assess methods of improving wind conditions around the proposed developments.

  • Our Approach

    As part of this project, RWDI:

    • Conducted pedestrian level wind microclimate assessments in accordance with City of London Wind Guidelines (which were informed by our expertise) to develop building design recommendations
    • Leveraged wind tunnel tests and collaborated with the design team to ensure the building design did not negatively impact pedestrian level safety and comfort
    • Analyzed and adjusted meteorological data for London to the site conditions by modeling the effect of upstream terrain roughness on the wind velocities approaching the site
    • Leveraged measurements from a comprehensive set of pedestrian locations within and beyond the site to inform meteorological data thoroughness and accuracy in testing and modeling
    • Monitored for adverse wind conditions from wind phenomena, such as downdraughting, wind channeling, and wind accelerations at building corners to provide accurate design recommendations from wind tunnel testing
  • The Outcome

    RWDI’s efforts helped the project verify pedestrian level wind comfort and safety through rigorous wind tunnel testing, successfully meet the City of London’s Wind Guidelines and deliver high-quality, enjoyable external spaces for workers, residents, and visitors alike.