A reference guide to simulation tools used in data-driven environmental design. Organised by analysis type with practical recommendations for different project stages. --- ## Energy Modelling **EnergyPlus** - Developer: US Department of Energy - Use: Detailed building energy simulation — heating, cooling, lighting, ventilation, water - Interface: Text-based input (IDF); accessed through front-ends like DesignBuilder, Honeybee, or OpenStudio - Strengths: The most validated building energy engine globally; used as reference by ASHRAE and most building codes - Limitation: Steep learning curve for direct use; requires expert interpretation of results - License: Free, open source **OpenStudio** - Developer: NREL (National Renewable Energy Laboratory) - Use: Graphical interface and SDK for EnergyPlus; supports Measure-based parametric studies - Strengths: Scripting via Ruby/Python for automated parametric analysis - License: Free, open source **DesignBuilder** - Developer: DesignBuilder Software Ltd - Use: Commercial GUI for EnergyPlus with integrated visualisation - Strengths: Most accessible EnergyPlus interface; good for practitioners without simulation expertise - License: Commercial --- ## Daylight Simulation **Radiance** - Developer: Greg Ward (LBNL) - Use: Physically-based lighting simulation — the gold standard for daylight analysis - Metrics: Illuminance, luminance, daylight factor, spatial daylight autonomy (sDA), annual sunlight exposure (ASE) - Interface: Command-line; accessed through Honeybee, Climate Studio, or DIVA - Strengths: Physically accurate ray-tracing; validated against measured data; used for LEED daylight credits - License: Free, open source **Climate Studio** (also listed under tools) - Integrated Radiance-based daylight with compliance-ready outputs (LEED v4.1, BREEAM, WELL) - Fastest workflow from Rhino model to daylight compliance report --- ## Wind and Ventilation (CFD) **OpenFOAM** - Developer: OpenCFD Ltd / ESI Group (open source) - Use: General-purpose CFD — outdoor wind comfort, natural ventilation, pollution dispersion - Interface: Text-based; accessed through Butterfly (Grasshopper) or BlueCFD - Strengths: Free; extremely capable; used in research and professional contexts - Limitation: Very steep learning curve; requires CFD expertise for reliable results - License: Free, open source (GPL) **Autodesk CFD** - Developer: Autodesk - Use: CFD with BIM integration (Revit) - Strengths: More accessible than OpenFOAM; good Revit interoperability - Limitation: Less flexible than OpenFOAM for complex scenarios - License: Autodesk subscription **SimScale** - Developer: SimScale GmbH - Use: Cloud-based CFD (and FEA) with web interface - Strengths: No local hardware requirements; good for firms without simulation workstations - License: Free tier available; commercial for full capabilities --- ## Outdoor Comfort & Urban Microclimate **ENVI-met** - Developer: ENVI-met GmbH - Use: Urban microclimate simulation — outdoor thermal comfort, vegetation effects, air quality - Strengths: The leading tool for urban-scale thermal comfort; models vegetation, water features, and soil - Limitation: Computationally expensive; simulation times can be very long - License: Commercial; academic licenses available **Ladybug Tools (Dragonfly + Urban Weather Generator)** - Use: Urban heat island effect estimation; district-scale energy modelling - Strengths: Free; integrated with Grasshopper parametric workflows - Limitation: Less detailed than ENVI-met for microclimate; better suited for comparative studies than absolute predictions --- ## Acoustic Simulation **Pachyderm Acoustical Simulation** - Developer: Arthur van der Harten - Platform: Grasshopper/Rhino plugin - Use: Room acoustics simulation — reverberation time, speech intelligibility, sound ray tracing - Strengths: Integrated into parametric design workflow; good for concert halls, lecture theatres, offices - License: Free, open source **ODEON** - Developer: ODEON A/S - Use: Professional room acoustics simulation - Strengths: Industry standard for concert hall and auditorium design; validated against measured data - License: Commercial --- ## Weather Data Sources **EPW Files** (EnergyPlus Weather) - Source: climate.onebuilding.org (free, global coverage) - Content: Hourly data for a typical meteorological year — temperature, humidity, wind, solar radiation, precipitation - Use: Input for all Ladybug Tools, EnergyPlus, Climate Studio analyses - Coverage: 3,000+ locations worldwide - Limitation: Based on historical data; does not reflect climate change projections **Future Weather Files** - Tool: CCWorldWeatherGen (University of Southampton), Meteonorm - Use: Morphing historical EPW files with IPCC climate projections to create future weather scenarios - Application: Testing building designs against projected 2050 and 2080 climate conditions --- ## Practical Recommendations by Project Stage | Stage | Tool | Purpose | |-------|------|---------| | Competition / concept | Autodesk Forma | Quick solar, wind, daylight assessment | | Schematic design | Ladybug + Honeybee | Parametric environmental analysis | | Design development | Climate Studio or Honeybee | LEED/BREEAM daylight compliance | | Design development | EnergyPlus via Honeybee | Detailed energy model | | Specialist studies | OpenFOAM via Butterfly | CFD wind/ventilation analysis | | Urban design | ENVI-met or Dragonfly | Outdoor comfort and microclimate | | Post-occupancy | Sensor platforms + dashboards | Measured performance verification |