What effect does a poorly insulated attic have on a HERS rating?

A poorly insulated attic contributes to higher energy consumption because it allows significant heat transfer between the living space and the outside environment. In winter, heat escapes through the attic to the colder outside, making heating systems work harder to maintain comfortable temperatures indoors. Similarly, in the summer, heat from the outside enters the attic, raising the temperature in the living spaces below and causing cooling systems to operate more frequently and for longer periods. This increased demand for heating and cooling results in greater energy consumption. Consequently, a home with inadequate attic insulation will receive a lower HERS rating, reflecting its higher energy use due to inefficient thermal performance. Thus, higher energy consumption directly correlates with poor attic insulation.