Sarah Max of Money magazine includes Joe Heider, president of Cirrus Wealth Management, in an article about smart moves when downsizing your home. “A mortgage is relatively inexpensive money, it’s tax deductible, and it means that you don’t tie up all of your cash in your home. If you’re working, mortgage payments should top out at 28 percent of gross income. But if you’re retired, aim closer to 15 percent,” he advises.