Can you buy a house with a down payment under 20 percent of the purchase price? Yes. However, it’s important to understand you’ll probably encounter extra expenses—and there are some pros and cons to consider.

Until the late-1950s, plaster walls were the norm in new home construction. These walls are sometimes called “horse-hair plaster” because it was common to mix horse hair into the wet plaster to add strength, and to prevent cracking with minor flexing. Heating and cooling a house will cause plaster to expand and shrink slightly, so the hair helped keep the walls a bit more flexible.

For lenders, the standard “rule of thumb” is that an individual’s monthly housing payment (your mortgage, plus taxes, insurance, etc.) should be no more than 28 percent of your monthly income, before taxes. In cases like FHA loans, the debt-to-income ratio may be higher.

But how much should YOU borrow?