Vastu Shastra Chapter 17 – Windows, Doors & Daylight: Openings That Breathe

Why openings matter (the lungs of the house)

Walls hold your life; openings make it livable. In Vastu, windows and doors tune Air and Light so the home can inhale and exhale without wheeze. Practically, good openings give you daylight that doesn’t scorch, air that moves without dust storms, and views that calm instead of broadcasting chaos. Get them wrong and you’ll fight glare, heat, stale corners, and mosquitoes that RSVP uninvited. Get them right and the whole plan feels smarter than its square footage.

Orientation by quadrant & climate

North & East (clarity light): Soft, even light that suits studies, pooja, kitchens, and work desks. Vastu loves this; so do eyes. Use generous windows with simple shading.
South (strong sun): Powerful light and heat. Works for winter warmth in temperate zones; needs overhangs/fins and high-performance glass in hot climates.
West (afternoon heat): The drama queen. Views can be lovely, but glare and late heat are real. Use smaller, well-shaded openings or double-screen with blinds + sheer.
NE windows: Great for clarity; keep them visually light and clean (no bulky grills/storage).
SW windows: Keep them fewer/controlled; SW prefers weight. Use thicker curtains or external shading to calm afternoons.

Hot–dry: Small, well-shaded South/West openings, deep overhangs, and night purge ventilation.
Warm–humid: Big operable windows opposite each other, insect screens, and high vents. Shade first; AC last.
Composite: Balanced sizes, flexible shading (louvers/blinds), cross-vent for shoulder seasons.
Cold/temperate: Max East/North light; high-insulation frames; minimal leaks. South sun welcomed with controlled overhangs.

Sizing windows & doors: ratios that behave

Window-to-floor area (WFA): As a quick rule, 15–25% glazed area per room feels bright without becoming a glass toaster. Push higher on North/East if shaded; go lower on West/South unless you have excellent shading.
Window-to-wall ratio (WWR): Aim 20–40% on façades in warm climates; more requires better shading/glass.
Operable area: At least 40–60% of the window should open in naturally ventilated rooms so air changes actually happen.
Doors: Internal doors ~820–900 × 2100 mm. Main door 1000–1100 mm wide if space allows (see Chapter 16). Balcony sliders often 1800–2400 mm wide modules—ensure real ventilation slots, not just giant glass.

Sill & lintel heights (and why they feel right)

Living/dining sill: 600–750 mm lets you place furniture under windows and keeps seated views out.
Bedroom sill: 600–750 mm for privacy + breeze at bed height; higher if facing a close neighbor.
Kitchen sill: Above counter, typically 1050–1150 mm; use high operable panes for steam release.
Bathroom sill: 1050–1500 mm (privacy), with an exhaust fan. Frosted glass is your friend.
Lintel height: A consistent 2100–2250 mm (or aligned with door heads) makes interiors feel composed.
Clerestories: High-level strips near the ceiling pull hot air out and bring light deep into rooms without prying eyes.

Window types, frames & when to use them

Casement (side-hung): Best ventilation, easy cleaning, strong sealing. Use where wind direction is known; mind the swing in tight balconies.
Top-hung/awning: Great for rain-friendly ventilation; perfect over counters and in bathrooms.
Sliding: Space-savers for balconies; lower airtightness unless premium systems. Add brush + compression seals.
Fixed: For views and light; pair with operable panels so the room still breathes.
Pivot: Stylish, but tricky to seal; use sparingly with good hardware.
Frames: Aluminium (durable, slim; specify thermal breaks in extreme climates), uPVC (value, good sealing; mind UV quality), wood (warm, needs maintenance), steel (elegant, high skill required).

Cross-ventilation & stack effect (breeze choreography)

Opposite openings: Put windows on two sides of the room (ideally perpendicular façades). Even small secondary openings matter.
Height difference: Air loves a climb. A low inlet + high outlet (clerestory/vent) creates a stack effect that pulls hot air out.
Path is king: Keep the interior walking spine clear; breezes are shy of clutter. Louver door panels help air move between rooms.
NW window + NE outlet: In many Indian sites, prevailing breezes work well with an NW intake and NE relief; adjust to your local wind rose.
Vent area thumb rule: For natural ventilation, opening area ≈ 10–20% of floor area (more in warm–humid zones).

Daylight without glare: simple metrics & quick wins

Useful daylight: Aim for a daylit core that lets you work without artificial light for several hours. Even distribution beats big, bright hotspots.
Depth rule: Daylight typically reaches ~2–2.5× the window head height into the room. Taller heads or clerestories push light deeper.
Glare control: East/West are glare-prone—use sheers by day and blinds by afternoon. Matte interiors near windows prevent bounce glare.
Task placement: Put desks/dining near East/North windows; keep screens perpendicular to windows so reflections don’t bully your eyes.

Shading: overhangs, fins, louvers & blinds

Overhangs (chajjas): For vertical façades, start with projection depth ≈ 0.5–0.8× window height above sill for South; increase on West. Side fins help mornings/evenings.
Vertical fins: Great for low sun (East/West). Angle them to preserve views; pair with a top overhang for a full visor.
Operable louvers: Control light + privacy dynamically; aluminum/wood-composite louvers behave well in apartments with variable weather.
Interior blinds: Sheer for diffusion, roller blackout for sleep/media. Double-rail (sheer + blackout) gives you both without drama.
External screens: Bamboo/reed chicks or perforated metal tame West sun; keep them sturdy and safe in high winds.

Glazing & energy: heat, sound & UV control

Single vs. double: Double glazing improves thermal and acoustic comfort, especially near traffic and in extreme climates. In mild zones, targeted use (bedrooms, West/South façades) is cost-effective.
Low-E & selective glass: Reduces heat gain while passing light. Use on West/South; pair with shading to kill glare.
Acoustics: For noise, mass + airtightness matters. Use laminated panes, wider air gaps (12–16 mm), and compression seals. One tiny leak undoes fancy glass.
UV & fading: Laminated glass with UV interlayers protects fabrics/art; sheer curtains help too.
Frames & gaskets: Ask for multi-point locking, proper EPDM gaskets, and drainage weep holes that don’t clog.

Doors & sliders: movement, thresholds, and seals

Hinged balcony doors: Best seal and security; mind swing conflicts with furniture.
Sliding doors: Save space and offer big views; specify lift-and-slide or premium sliders for better sealing and smoother movement.
Thresholds: Keep them flush (rain pans + hidden drains) for accessibility; if raised, bevel <10–12 mm.
Hardware: Lever handles, solid cylinders, and child-safe restrictors for high floors. Use SS or good powder-coated finishes in coastal zones.
Seals: Door sweeps + compression seals cut dust, smell, and noise—especially at apartment entries (see Chapter 16).

Privacy, insects & security (quiet defenses)

Insect screens: Sliding/pull-down pleated screens let you ventilate without inviting a zoo. Clean them; dust kills airflow.
Frost/films: Bathrooms and close neighbors benefit from frosted or patterned films that admit light but block sight.
Grills: Keep designs simple and maintainable. For aesthetics, align grill divisions with window mullions so it doesn’t look like jail over jewelry.
Security: Multi-point locks, laminated glass, and sensors beat ugly bars. Cameras should never point into neighbors’ homes.

Apartments & retrofits: small moves, big relief

Cross-vent hack: If opposite windows aren’t possible, open a high transom into a corridor or adjacent room + a low inlet on the façade to fake a stack path.
Heat-taming film: Spectrally selective films on West/South reduce solar gain; pair with sheers to keep rooms bright.
Noise fix: Retrofit secondary glazing (an extra inside frame) where replacing windows is impractical; seal every perimeter gap.
Curtain logic: Ceiling-mounted tracks that run wall-to-wall make windows feel taller and seal edge leaks around blackout.
Plant shade: On balconies, climbers or planters act as living fins; choose non-invasive species and keep railings safe.

Short story: the flat that learned to breathe

Nikhil’s living room faced West like a gladiator—great sunsets, roasted evenings. A giant slider looked impressive and moved exactly zero air. We kept the view, swapped one fixed pane for an awning that could stay open during rain, added vertical fins on the outer edge, and hung a double-rail sheer + blackout. We sealed the frame gaps, installed a quiet ceiling fan, and put a small high vent into the dining. Result: same sunsets, half the heat, and the first monsoon that didn’t march straight onto the sofa. The room didn’t change its face; it changed its behavior.

12-point openings audit

1) North/East windows are generous and operable; West/South are shaded and controlled.
2) WFA ≈ 15–25% per room; operable portion ≥ 40–60% where natural ventilation is desired.
3) Sills and lintels are consistent; bedroom/living sills 600–750 mm; kitchen/bath higher for function/privacy.
4) Two-sided ventilation exists or is faked with high/low vents.
5) Overhangs/fins tame East/West; sheers by day, blinds by afternoon where needed.
6) Screens are clean and intact; no mosquito highways.
7) Frames seal properly—no daylight around gaskets; multi-point locks work.
8) Glass choice matches façade (low-E/laminated where heat/noise demand it).
9) Doors slide/swing without scraping; thresholds are flush or safely beveled.
10) Curtain tracks run wall-to-wall; blackout actually blacks out in bedrooms.
11) Views are calm; neighbors’ windows aren’t a TV of your life—use films/fins where needed.
12) Maintenance plan exists: clean tracks, screens, filters, and check seals quarterly.

FAQs

Are huge floor-to-ceiling windows good Vastu? Only if they behave—North/East with shading, proper seals, and privacy control. West/South full-height glass without shading is a glare-and-heat cannon.

Casement or sliding? For ventilation and sealing, casement wins. For tight balconies and big openings, premium sliders are practical. Often, a mix is best: fixed + casement + one slider where the view is king.

Do I need double glazing in a warm city? Not everywhere. Use it for noise or harsh West/South façades. Elsewhere, shading + good single glazing + airtight frames do most of the work.

How do I stop condensation? Ventilate (especially kitchens/baths), avoid cold-bridge frames, and keep blinds a little off the glass so air circulates.

What’s the single biggest win for apartments? Cross-vent path + shading. Even one added awning pane and a proper sheer/blackout combo can transform daily comfort.