Proper ventilation is essential to maintaining healthy humidity levels and preventing mold growth. Homes should have bathroom and kitchen exhaust fans that vent to the outside, not into attics or crawlspaces. Whole-house ventilation systems or energy recovery ventilators (ERVs) are a strong plus, especially for airtight or newer homes.

Indoor humidity should ideally remain below 50%. If you’re touring a home, use a portable humidity meter to check various rooms. Signs of condensation on windows, musty odors, or mildew on walls suggest poor ventilation. Homes in humid climates may benefit from whole-home dehumidifiers, particularly if mold sensitivity is a concern.