Daylight Analysis
Design-stage daylight feedback — LEED-style sDA / ASE, not certification-grade.
Simulates how much daylight reaches each point on your floor — every hour of every day for a full year — and reports LEED-style sDA / ASE plus glare risk. It's built for design-stage decisions, not for certification submission.
Daylight Analysis
Runs in the browser — nothing to install.
Free account required. Create one.
| Metrics | LEED-style sDA · ASE |
| Method | Perez + daylight coeff. |
| Input | .3dm + EPW |
How it works
The same method a validated engine uses, deliberately stripped for browser speed. Trust the relative reads (option A vs B, which rooms are dark, which window does the work) — the simplifications bias absolute numbers in a systematic direction, so comparisons hold up even where the raw values drift low.
- Perez all-weather sky model (same family as Radiance's gendaylit).
- 145-patch Tregenza sky dome with the daylight-coefficient method.
- Annual hourly integration driven by your EPW weather file.
- Per-window isolation + an hour-by-hour glare timeline.
- No EPW? Falls back to a steady-state CIE-overcast Daylight Factor (ballpark).
Using it
Upload your Rhino model
Drag a .3dm file into the viewer. Make sure floors, walls and windows are on separate, named layers.
Assign layers
Tell the tool which layers are Floor (analysed), Glazing (windows, VLT applied) and Wall (opaque context).
Load an EPW file
Pick a weather file for the project location — the sun-position math depends on it.
Set parameters
Glazing VLT (65% for clear double glazing), Workplane Height (0.76 m for desks), Grid (start at 1.5 m).
Run & read results
sDA ≥ 55% and ASE ≤ 10% = LEED v4.1 pass. Click a cell to see why that point is bright or dark.
What to trust it for
- Comparing design options (window size, orientation, massing) side by side.
- Spotting gloomy or glare-prone rooms early.
- Window-to-floor / depth-of-plan sanity checks.
- Pre-screening a model before paying for a stamped daylight study.
What not to use it for
- USGBC LEED credit submission.
- Building-code compliance sign-off.
- Stamped engineering deliverables.
Known limits
- Diffuse interreflection via radiosity (multi-bounce); specular/mirror reflections are not modelled.
- Fixed surface reflectances (wall 0.5 / ceiling 0.8 / floor 0.2), not material-specific.
- No automated-blind protocol — it's LEED-style sDA, not true LM-83 sDA.
- Simplified glazing (VLT per pane, no angle dependence) and a single sun ray (no penumbra).
- Benchmarked vs Radiance across 8 space types (rooms, skylight, deep/tall, various windows): average Daylight Factor agrees within ~3–11%; annual sDA within ~12% (normal inter-model spread). Near-window reads slightly high, deep corners slightly low — treat absolute values as directional.
Tips
- Do — Start with a coarse grid (1.5 m). Only refine once layer assignment is correct.
- Avoid — Forgetting to assign Glazing layers — the tool will treat windows as opaque walls.
- Avoid — Changing VLT, grid, and EPW between two runs. Change one variable at a time.
Daylight Analysis
Runs in the browser — nothing to install.
Free account required. Create one.