All bedrooms must have at least one window to the outside with an area equal to what fraction of the total floor area?

The requirement for all bedrooms to have a window that provides adequate natural light and ventilation is based on the total floor area of the room. Establishing a window area of at least one-tenth of the total floor area ensures that the room meets health and safety standards, promoting a healthy living environment.

This specific fraction ensures that enough light enters the room, which is essential for psychological well-being, as well as for practical aspects such as safety in case of emergencies. Additionally, having this minimum window size helps to improve air circulation, which is important for maintaining indoor air quality.

The other options suggest different fractions, but having a window that is smaller than one-tenth of the total floor area may not provide sufficient light or ventilation, potentially leading to a less safe and unhealthy environment. This is why the requirement is set at one-tenth, as it strikes a balance between adequate natural lighting and ensuring structural integrity within regulatory standards.