analysis_periodselectdefault: annualannual | summer_solstice | winter_solstice | equinoxTime period over which solar access is accumulated.
Annual gives the full-year picture. Summer solstice (Jun 21) shows peak-day access — useful for PV sizing. Winter solstice (Dec 21) reveals worst-case shading — critical for public space quality.
time_step_hnumberdefault: 10.5–2 (step 0.5)Interval between sun position samples. Smaller values are more accurate but slower.
1-hour steps are sufficient for most planning decisions. Use 0.5 for detailed PV assessments.
target_surfaceselectdefault: rooftoprooftop | pedestrian | south_facade | allWhich surface to compute solar hours for.
Rooftop is most relevant for PV. Pedestrian level (1.5 m) drives public space comfort. South facade is key for passive solar design.
min_solar_hoursnumberdefault: 1000100–4000 (step 100)Buildings below this threshold are flagged as shading-constrained.
BRE guidelines recommend at least 2 hours on the winter solstice for public amenity spaces. Use 1000 annual hours as a minimum for meaningful PV yield.
Start with Annual + Rooftop to identify buildings with strong PV potential. Switch to Winter Solstice + Pedestrian to assess public space shading from new buildings. Comparing scenarios: run on a baseline, then add or remove buildings in a scenario and run again to see how the solar access budget shifts.