What is the minimum glazing area of a habitable room?

The minimum glazing area of a habitable room is determined by building codes that stipulate adequate natural light and ventilation for such spaces. In many jurisdictions, including Minnesota, the requirement is based on a percentage of the room's floor area to ensure that there is enough glass surface to allow sufficient daylight into the room.

The correct answer reflects this common requirement, stating that a minimum of 8% of the room floor area should be comprised of glazing. This standard keeps the indoor environment comfortable and also contributes to energy efficiency by reducing the need for artificial lighting during the day.

In contrast, other percentages, such as 4%, 6%, or 10%, do not align with these established minimum standards. For instance, while lower percentages might not provide sufficient natural light, a higher percentage, like 10%, could exceed typical requirements and potentially impact construction costs and energy efficiency without providing any added benefit in terms of light or ventilation.