If the value of one's house increases, what will likely happen to the mortgage principal?

When the value of a house increases, the mortgage principal itself does not change simply because the property value has gone up. The mortgage principal is the original amount borrowed or the remaining balance of a loan that is to be repaid. This amount is contractual and does not fluctuate based on the market value of the home.

While the homeowner’s equity in the property may increase due to the rise in value (as equity is calculated by subtracting the mortgage balance from the current market value), the principal owed on the mortgage remains unchanged unless the homeowner actively makes additional payments or refinances the loan. This demonstrates that property value and mortgage principal are two separate factors; thus, when the property value rises, the mortgage principal remains the same unless influenced by the homeowner's direct actions regarding the loan.