How does improper insulation affect heating and cooling efficiency?

Improper insulation significantly promotes air leakage, which negatively impacts heating and cooling efficiency. When insulation is not installed correctly or is insufficient, it allows warm air to escape during winter and cool air to dissipate during summer. This kind of uncontrolled airflow leads to higher energy consumption because heating and cooling systems must work harder to maintain comfortable indoor temperatures. As a result, homeowners experience increased energy costs, as the systems are less efficient due to the loss of conditioned air. Proper insulation should act as a barrier to prevent air movement, thereby optimizing energy efficiency and minimizing energy bills. The other options do not reflect the reality of how insulation performance affects energy efficiency.