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Natural Ventilation & Daylight Calculator
Calculate the minimum ventilation opening and daylight window area for a room to be healthy, bright, and cool. Free.
Note
An early-planning estimate; final design & permit compliance (PBG) should be done or verified by a competent architect/engineer.
Suggested opening area
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Understanding natural openings
Natural ventilation
Openings that move air (windows, vents). A common guide is at least ~5% of the room floor area, ideally with openings on two different sides for cross-ventilation.
Natural daylight
Openings that admit sunlight (glass windows). A common guide is ~10–20% of floor area, so the room is bright enough by day without lamps — saving power and healthier.
Orientation & layout
Beyond area, opening position matters: facing the right wind and light direction. An architect helps balance brightness, coolness, privacy, and glare.
FAQ
Frequently asked questions
How do I calculate a room's ventilation area?
Multiply the room floor area by the minimum ventilation ratio (a common guide ~5%). A 12 m² room × 5% = 0.6 m² of ventilation opening. Ideally openings sit on two sides for cross-ventilation.
What's the ideal window-to-room ratio?
For daylight, a common guide is ~10–20% of floor area. A 12 m² room should have roughly 1.2–2.4 m² of window. Deeper rooms or darker walls should have larger openings.
What's the difference between ventilation and daylight?
Ventilation is about AIR flow (avoiding stuffiness and damp); daylight is about LIGHT entering. One window can serve both, but vents serve only ventilation, and skylights mainly light.
Are there official rules on this?
There are building comfort and health guidelines (referencing SNI and building standards), but figures vary by room function and context. This calculator uses common values you can adjust.
What if a room has few openings?
Rooms with too few openings tend to be stuffy, damp, and dark — risking mold and wasted electricity. Solutions include adding windows, a void, skylight, or mechanical ventilation. An architect can help arrange it.
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Luxury Art — Architecture & Interior
The planning is set. Now the design.
The calculator here helps you plan space & massing with numbers. Turning it into a beautiful, functional, compliant design takes an architect — that's where Luxury Art works. We handle architecture design, interior design, working drawings, and PBG permit conformity & processing.
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