Ladybug Tools
Free open-source Grasshopper plugins for climate analysis, energy modeling, daylighting, CFD, and urban simulation, with a commercial cloud layer via Pollination.
4.4 /5 composite score
The most comprehensive free performance toolkit available -- Ladybug (climate), Honeybee (energy/daylight), Dragonfly (urban), and Butterfly (CFD) cover the full building science stack; the Pollination commercial layer adds Revit connectivity at $2,750/year if needed.
Worth it for a firm of one
Rubric Scorecard
| Criterion | Score | Rationale |
|---|---|---|
| Maturity | 4/5 | 500,000+ downloads, 3rd most downloaded Grasshopper plugin; used by Foster+Partners, BIG, Arup, and SOM; DOE-featured project; IBPSA academic paper from 2013 confirms long research lineage. |
| AEC Specificity | 5/5 | Covers climate analysis, annual energy simulation (EnergyPlus/Radiance), daylighting (LEED/BREEAM), CFD (OpenFOAM), urban heat island, and PV -- the broadest scope of any free tool on this list. |
| Integration | 3/5 | Grasshopper/Rhino-native; Pollination extends to Revit ($2,750/yr) and cloud runs; free core requires Rhino license; no standalone app. |
| Value / Pricing | 5/5 | Core plugins are free and open source; Pollination Grasshopper plugin free; Rhino plugin $1,375/yr, Revit plugin $2,750/yr; monthly options available; free core is fully functional for most solo work. |
| Evidence | 5/5 | DOE feature article on Pollination; IBPSA 2013 conference paper; Food4Rhino marketplace listing with download count; widely cited in academic literature. |
How we verified this: we checked Ladybug Tools against its live site and an independent source — energy.gov. Nothing on this page is listed from memory. See how we review. Verified 2026-06-29.
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