Mortgage underwriters and personal finance advisers recommend that Americans spend no more than 28% to 30% of their income on housing costs.<br />And according to Certified Financial Planner and Business Insider contributor Tanza Loudenback, it's a very good rule of thumb if you want to build wealth.<br />Of course, to achieve this, you may have to take a few deep breaths along the way and do things like sharing with roommates or renting the 'worst' bedroom.<br />However, by keeping your long-term fixed housing costs to less than 30% of your take-home pay, you can be far more flexible with the rest of your budget.<br />But remember, 'housing' costs don't just include rent. Utilities, such as power, water, sewage, garbage collection, cable, and internet all add up quickly.<br />Even so, living by the "30% rule" for housing can let you funnel more and more into retirement savings and other investments as your income improves!