Q: I heard that sealing your home too much is not good because your house needs to breathe.

A: Yes, that is true. Air circulation evaporates water that inevitably condenses in walls in spring and fall. Please see my other answers to people’s questions on moisture on this page. However, it is almost impossible to seal an existing house so well that you get moisture problems. It happens far more often on new construction, particularly on houses built to the Passive House standard with requires almost no infiltration of air. The best way to deal with condensation in a house is to control the humidity which is easy to do with heat pumps. Please see my other answers on condensation and moisture problems in houses on this page. Condensation in houses is the most insidious problem in houses today.