What is the minimum vertical extension required for a chimney relative to any building feature?

The minimum vertical extension required for a chimney in relation to any building feature is specified as 2 feet. This regulation ensures that the chimney is adequately high enough to allow for proper dispersion of combustion gases and to prevent down-drafting, which can lead to unsafe conditions inside the building.

This height helps to ensure that the smoke and other byproducts of combustion are expelled above the roofline, thereby minimizing the potential for fire hazards and maintaining air quality around the building. Proper chimney height is critical for effective ventilation, as it enhances draft performance, ensuring that smoke rises away from the building and that any potential toxic fumes are safely directed upwards and away from openings such as windows and doors.

The other options suggest greater heights, which while they may provide additional safety in certain instances, do not represent the minimum requirement set by building codes. Adhering to the minimum specification is essential for compliance with safety standards while ensuring functional performance.