Auriel — Natural Light Score

Point your phone at any window. Get a 0-100 natural light score in seconds. Know if an apartment is actually bright before you sign.

Use it for apartments, homes, windows, and garden spots to see how much usable light you actually get.

That number is your Sun Score - how much usable natural light that spot receives across an entire year, not just right now. It accounts for the sun's changing path, your exact orientation, nearby obstructions, and your regional climate. No other app gives you this.

HOW IT WORKS

In Window mode, aim at the glass and tap. Auriel runs a full 12-month solar analysis for that exact orientation - computing the sun's angle of incidence hour by hour, weighting direct and diffuse light, adjusting for regional cloud cover - and delivers a score in seconds.

In Garden mode, stand at your spot and scan around you. The app detects shade from trees, fences, and buildings, then calculates your effective growing light and daily light integral (DLI) to show what will thrive there.

WHO IT'S FOR

- Apartment hunting? Score every unit's windows before you sign. "This one's a 78, the other was a 34."
- Growing a garden? Stop guessing whether your spot gets enough sun for tomatoes or if you should stick with hostas.
- Choosing blinds or curtains? See exactly how much light each option blocks with industry-standard transmittance data.
- Selling a home? "South-facing living room, Sun Score 84" is a better listing than "lots of natural light."

FEATURES

- Sun Score (0-100) with letter grade for any spot
- AR sun path overlay on your camera view
- Garden mode with shade detection and DLI calculation
- Window mode for full-year light exposure analysis
- Seasonal heatmap across all 12 months
- Covering simulator with real transmittance values
- Surface calculator with kWh and optimal tilt angle
- Golden hour and peak sun notifications
- Save and compare multiple locations

THE SCIENCE

Each Sun Score is the result of a multi-factor solar analysis:

- Sun position calculated using the NREL Solar Position Algorithm - the U.S. Department of Energy standard, accurate to 0.01 degrees
- Hour-by-hour light modeling across 365 days for the specific surface orientation and tilt
- Direct and diffuse light components weighted by angle of incidence
- Climate adjustment using regional sunshine probability data covering 50+ zones worldwide
- Real-world obstructio