What is typically required for framing windows to ensure proper installation?

The correct answer focuses on the importance of using correctly sized headers when framing windows. Headers are horizontal structures that support the weight of the building materials above a window. Properly sized headers are essential because they ensure that the load is evenly distributed, preventing structural issues such as bowing or sagging over time. They also play a crucial role in maintaining the integrity of the window installation, ensuring that it is secure and capable of withstanding external forces such as wind and weather.

In framing, other elements like moisture prevention, double framing, and insulation are also important, but they do not directly address the structural support needed for window installations. While moisture prevention is crucial for overall building integrity, it is not specific to window framing. Similarly, double framing may be beneficial in certain contexts for added strength, but it is not a standard requirement for every window installation. An extra layer of insulation can help with energy efficiency and comfort, but it does not relate to the structural framing aspect of window installations. Thus, ensuring that headers are correctly sized stands out as the most critical factor in proper window framing.