One of the important first steps you can take when you’re considering building a new home in New Jersey is establishing a realistic budget. Your budget determines how much home you can really afford—which helps when you’re checking out a variety of floor plans. It’s also key in making decisions about what options and upgrades you choose.

Fortunately, there are a lot of free online mortgage calculators out there that can give you a pretty good general idea of what you can afford. The key word in that previous sentence is “general,” because there are some things a mortgage calculator won’t tell you—and that can get you into trouble if you’re not careful to watch out for them.

Using a mortgage calculator to figure out your budget can be a good first step, but these calculators often focus exclusively on how much money you as a homeowner earn, what your existing expenses are and what the PITI (principal, interest, taxes and insurance) payments on your new home will be. There’s more to the picture than that. Other considerations include:

Dues and Fees

When you’re calculating your budget, you can easily forget about what seem to be relatively small charges. There are fees for inspections, charges for access to utilities, homeownersassociation dues and connection fees for cable, electricity or water. Each individual charge or fee may not be that significant, but together they can add up to a sizeable sum you weren’t counting on.

Rising Interest Rates

If you’ve shopped for loans before, you probably know that interest rates on home loans can change quickly (even in the course of a day).  If your budget is so tight that a small, sudden rate hike makes your home unaffordable, you could find yourself in trouble.

Emergencies and Unexpected Events

A mortgage calculator doesn’t have a special button for events such as a car accident, a mechanical breakdown or surprise medical bills. Will your homebuying budget still work if you face that kind of event?

Increasing Taxes

Even though a mortgage calculator factors in property taxes, you could be caught off guard if your property taxes increase with time. Will your budget be able to accommodate an increase in taxes?

Options

It’s always a good idea to allow a certain amount of money for add-ons. Some upgrades and options will really make your home more comfortable for your lifestyle. But these selections do cost a little more. You want to make sure you have enough room in your budget to take advantage of important changes to your original plan.

None of these things should keep you from purchasing a home, but you need to keep them in mind as you prepare your budget and decide which home is right for you. A realistic budget will help you get into—and stay in—a home you can really afford.