As a contractor, and ICF sales, installation and technical rep, the biggest (nearly only) complaint I ever received regarding ICF homes was when they were improperly ventilated due to the HVAC system being poorly designed. Any home that is built or retrofitted to be airtight needs to have some form of metered air inflow and outflow to replace any air lost by way of combustion or ventilation of bath fans, dryers, range hoods, water heaters, furnaces, breathing, pets, etc. Without this ability to "breathe" an airtight home will quickly build moisture and allergens, which will result in an unhealthy indoor air quality, and eventually will contribute to mold growth inside the home. Proper design of the home and HVAC systems are crucial in preventing this! Thanks, Mike and team! Mike, I'd love to chat further. We met briefly in Cleveland. Let's do lunch. -Dusty

Great information!