| Requirement | Notes |
|---|---|
| All habitable rooms have an openable area in a window or door, opening to external air to allow sufficient ventilation, easily and safely openable by the occupiers and in a suitable position | |
| Basements used as habitable room must have a window opening with space outside with a width to the boundary of at least 600mm or 300mm if a bay window | |
| Kitchens, bathrooms and WCs shall have an openable window or have an extractor fan |