Signs of old attic insulation is bad, include increased energy bills, temperature fluctuations, drafts, cold spots, presence of pests, water damage, or visible mold. Regular inspections can help identify these issues. Temperature inconsistencies throughout your living spaces, often indicated by varying hot and cold spots, can signal inadequate insulation. If your HVAC system struggles to maintain a consistent indoor temperature, it could be due to bad insulation. High energy bills that can't be attributed to seasonal changes or increased usage might point to insulation problems. Poor insulation forces your heating and cooling systems to work harder to maintain the desired temperature, leading to increased energy consumption. Visual signs such as water stains, damp spots, or even visible mold growth on the insulation matter are clear indicators of bad insulation. Moisture intrusion can rapidly deteriorate insulation effectiveness and compromise indoor air quality. Drafts and inconsistent indoor airflow suggest that the insulation might not be effectively sealing the building envelope.