What percentage of the floor area should the total net area of window glass be less than?

The correct answer indicates that the total net area of window glass should be less than 8% of the floor area. This guideline is often derived from building codes and standards that aim to maintain energy efficiency and ensure structural integrity.

Having a limit on window glass area is important for several reasons. First, excessive glazing can lead to increased energy consumption due to heat loss in the winter and heat gain in the summer, which can strain heating and cooling systems. By keeping the window glass area within a certain percentage, builders can help ensure that homes remain comfortable without excessive energy usage.

Additionally, limiting window area contributes to the structural integrity of the building. Each window installation requires careful consideration of thermal performance and the weight distribution of the walls. If too much area is dedicated to windows, particularly on load-bearing walls, it can compromise the building's strength.

The designation of 8% provides a balance that encourages natural light while also considering energy efficiency and structural performance.