Which feature of windows is particularly assessed for determining its effect on energy costs?

The quality of glazing is a key aspect of windows when assessing their impact on energy costs. Glazing refers to the glass used in windows, and its properties significantly influence thermal performance. Well-designed glazing can help minimize heat transfer, enhancing energy efficiency in both heating and cooling seasons. Factors such as the number of glass panes, the type of gas used between panes, and the coatings applied to the glass all contribute to how much heat and light can pass through, thus affecting energy consumption.

High-quality glazing can reduce energy costs by improving insulation, lowering heating bills in the winter, and minimizing cooling costs in the summer. This property makes it a critical element in energy-efficient building practices and standards, which is why it is particularly assessed during inspections focused on energy efficiency.

The other elements, such as window frame style, UV protection capability, and overall window size, do play roles in the window's performance and energy usage, but glazing quality directly impacts how the window functions in terms of energy conservation.