Window Tool

Window Shade Depth Calculator

How deep should the overhang or chajja project to shade a window through the Indian summer? Pick the orientation, your city latitude and the window height to get the recommended projection depth and an orientation-specific passive-cooling tip. A rule-of-thumb — indicative, not a substitute for a sun-path study.

Your window

Window faces

City / latitude

Window height (ft)

Shade how much?

Summer-noon sun altitude here ≈ 85° (sun sits near the Tropic of Cancer in June). Shades the hottest midday hours. This is a single-window rule-of-thumb — a full sun-path / shadow-angle study refines it.

Recommended overhang projection

0 mm

≈ 0.36 ft deep · projection ratio P/H = 0.09

Orientation

South

Best device

Horizontal chajja / overhang

Depth (ft)

0.36 ft

horizontal overhang

P/H ratio

0.09

projection ÷ height

A horizontal chajja / overhang projecting ~0.36 ft (109 mm) shades this south window when the summer sun is high. South sun is steep, so a modest projection blocks it at noon while still letting in low, useful winter sun.

Horizontal-overhang shade by orientation

How well one horizontal overhang of the same depth shades each face — it favours the south, which is why E/W need a different device.

Design shading that fits your climate

DesignAI sizes chajjas, fins and louvers to your orientation, latitude and façade — passive cooling, built in.

Use in DesignAI

Go deeper

Window shading strategies Reducing window heat gain Solar heat gain & windows All window guides

Related Guides — Deep-dive reading

South-Facing Window Design (India): High Sun You Can Actually Shade

Why the south wall's high midday sun is the easiest to block, how to size a chajja by latitude, and how big south glass works with the right shade and glass

Windows & Glazing

Climate-Responsive Facades for India: Designing Your Home's Skin for Your Weather

A homeowner's plain-language guide to the facade strategy for every Indian climate zone — what your walls, windows, shading, and colours should actually do where you live

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Brise-Soleil, Louvre and Fin Facades in India: Fixed External Sun-Shading That Beats the Heat

A plain-English guide to fixed external shading — horizontal louvres, vertical fins, eggcrate, baguettes and chajjas — and how to size and orient them by facade direction so they actually stop the sun before it hits your glass.

Building Facades

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