Natural Light Score Calculator
Score any room’s daylight from 0 to 100 using its window size, orientation, glass, obstruction and depth — then see the biggest limiting factor and how to fix it. Indicative India 2026 logic; confirm with an on-site daylight check.
Your room
Glazed area as a share of the room’s external wall. Typical Indian rooms: 15–35%.
Steadiest, brightest daylight in India year-round. Back of room starts to dim. Real daylight also depends on wall colour, sill height and time of year.
Natural light score
0 / 100
GoodComfortable daylight across most of the room.
Biggest limiter
Window size (glazing ratio)
68% of ideal
Glazing ratio
25%
window vs wall
Glass VLT
0.80
visible light transmittance
Sky access
100%
after obstruction
Factor contribution (terracotta = limiting)
How to raise this score
- •Enlarge the window or add a second one — aim for 30–40% window-to-wall ratio.
- •Use pale ceilings and a high window head to push daylight toward the back wall.
Design rooms that fill with daylight
DesignAI sizes windows, orientation and glass to your room, climate and budget.
Related Guides — Deep-dive reading
Daylighting Indian Homes and Buildings
NBC 2016 Part 8, IS 2440, and the Science of Natural Light — A Comprehensive Guide for Architects
ConstructionNorth-Facing Window Design (India): The Best Light With the Least Heat
Why the north wall gives soft, even, glare-free daylight with almost no heat, and how to design large, high-VLT windows that make the most of it.
Windows & GlazingWindow Design for Natural Light (India): A Brighter, Evenly Lit Home
How to size, place and glaze windows so every room is bright and evenly lit, without glare or gloom
Windows & GlazingRelated Tools — You may also find these useful
Daylighting Calculator
Estimate a room's average daylight factor, daylit depth and natural-light adequacy from glazing and VLT.
Window ToolWindow Orientation Planner
Pick the best window type, glass and shading by wall direction — north, east, south and west.
Window ToolWindow Size Calculator
Get the right window size, glazing area and openable area for any room using NBC daylight rules.
Window Tool