| Primary value | 1.0 m² |
| Applies to | Standalone kitchens · Separate cooking rooms |
| Exceptions | Combined kitchen-dining (open) → Ventilation via dining |
| Measured as | Total openable window area in the kitchen wall — must connect to outside air directly. |
| Source | NBC 2016 — Part 4, Clause 4.3 ✓ Verified |
Cooking generates moisture, smoke, and odours. 1.0 m² of openable window provides the minimum exhaust area for natural ventilation when no mechanical exhaust is installed.
Most kitchens provide 1.5–2.0 m² of window plus a chimney/exhaust. Internal kitchens (no external wall) require mechanical ventilation only.