The primary aim of this analysis was to assess outdoor comfort across a 128,000 m² semi-open plaza using the Universal Thermal Climate Index (UTCI). UTCI is a comprehensive metric that integrates solar radiation, infrared radiation, dry-bulb temperature, humidity, wind speed, clothing factor, and metabolic rate.
The work mapped the plaza’s microclimate and informed an optimum design strategy targeting the best comfort performance per location. The study was run at early design stage and successfully carried into later design phases.
I built the analysis algorithm in Grasshopper 3D using Ladybug Tools, TRNlizard, and TToolbox to assess outdoor comfort across the plaza.
CHALLENGES
- Mapping outdoor comfort across a 128,000 m² plaza for every season using UTCI.
- Capturing the influence of dry-bulb temperature, MRT, wind velocity, and relative humidity on user comfort.
- Optimising the design for the highest seasonal comfort with localised solutions.
- Handling complex context geometry with double-curvature surfaces.
- Processing a highly detailed terrain mesh of several million faces.
WORKFLOW
- Static calculation without context geometry, driven by weather-file inputs.
- Geometry meshing and optimisation; creation of the analysis grid.
- Simulation setup using Ladybug Tools and TRNlizard inside Grasshopper 3D.
- Parametric simulation across multiple variants per season.
- Post-processing through a custom Excel pipeline.
- Visualisation in Grasshopper 3D.
ACHIEVEMENTS
- Automated geometry handling and meshing pipeline that drastically reduced simulation time.
- Automated UTCI outdoor comfort workflow built in visual scripting, including analysis and visualisation.
- Timely early-stage design recommendations delivered to the architects.
- 10x simulation speedup vs the company’s previous detailed outdoor simulation workflow.
UTCI AND SUN HOURS MAPPING
Results show favourable comfort at the centre of the building thanks to summer sun angles and the smaller aperture at that point. At the extremes, further design changes would be needed to improve outdoor thermal comfort.
Possible changes include building geometry optimisation or local comfort strategies: shading, evaporative cooling, or radiant cooling.
