hoped for more detail what was meant as "substantial" than something that generally maintains home's value....e.g. I'm in the home so that alone (my presence)  maintains my home's value but likely to increase the value by 100%, at least. increases my home value to an incredibly higher value . Thanks for the prompt answer. I was now able to realize my (even better this year) standardized ded coupled with the fact I've never needed to itemize made me realize I don't need the interest write off on my HELOIC anyway.....and that's just fine 🙂  xo