Window Guide · Kolkata
West-facing Toilet
West is an acceptable secondary Vastu placement for a toilet. Window design tunes to Kolkata's warm-humid climate.
The recommendation
These figures are advisory — drawn from IS 3792 (Warm-Humid zone) and Vastu Shastra teaching tradition. An architect should adapt them to your plot's exact bearing, plinth height and facade design.
Why this direction for a toilet?
Toilet windows are entirely about ventilation and a single shaft of light — small, high-sill, opaque or louvred glass for privacy. An exhaust fan + a small openable window is the standard, never just one or the other.
Children, gains, dining. The afternoon-light direction — manage with shading.
Vastu's ideal placement for a toilet is NW. West is an acceptable secondary band.
Why Kolkata's climate matters
Kolkata is in the Warm-Humid climate zone (Aw, Am, Af per the Köppen scale; Warm-Humid per NBC 2016). Summer temperatures: 30-38°C, winters: 18-28°C. Rainfall: 1000-3000 mm/year. Humidity: >70%.
Verandahs are not decoration here — they are the building's lungs. Skip them and the house cannot breathe in monsoon.
For a west face in this climate, the recommendation is a sliding 2t (cross-ventilation) window with clear glazing and a sill at 3.5' — calibrated for year-round high humidity, moderate temperatures, and monsoon-driven cross-ventilation.
Common mistakes
- Clear glass at eye-level instead of frosted / louvred
- Window opening onto the same shaft as the kitchen — odour transfer
- No window at all — dependence on exhaust fan alone, which fails when power cuts
- Treating it as an air-conditioning problem — in Kolkata's humidity, cross-ventilation across opposite walls always beats sealed AC reliance.