Is there anything more satisfying than walking through the door of a new home that you helped design? On the other hand, staring down at a blank floor map can lead to a labyrinth of questions, headaches, and regrets. That’s why we’ve collected the top screw-ups people make when building their dream home from scratch so you can bypass these snafus yourself and move into a place that fits your vision—to a T!

Homebuilders follow your lead—not the other way around. So if you’re not exactly sure what you want your home to look like, they may steer you toward the usual tried-and-true stuff, whether that’s a formal dining room or a standard-size upstairs master bedroom. But Tim Costello, CEO of Builder Homesite in Austin, TX, calls this a new owner’s “biggest pitfall,” resulting in a custom house that somehow feels generic.

“The whole joy of buying new is that you can actually customize it,” says Costello. “So come with inspiration. What homes—or unusual home features—have you seen that you really liked?” Find photos of homes in magazines that make you swoon, then show them to your developers to give them an idea of your needs and desires.

The nitty-gritty of building a house can be intimidating. There are numerous decisions to make, from massive (deciding where to erect walls) to minuscule (picking light fixtures). This overload of choices can short-circuit some buyers’ brains so they become paralyzed, unable to make any decision at all.

To avoid facing 100 overwhelming questions about bathtubs and windows in one sitting, ask your builder to set up a personalized website, allowing decisions to be made at your leisure. No website? Simply create a binder with your architect and/or builder where choices are organized room by room, step by step.

One of the major perks of building a home is that your contractor can, well, build things into it—everything from shelves to entertainment centers—that will blend in seamlessly with the walls and floor. But since many homeowners are accustomed to buying this kind of furniture when they move into a used home, this option often gets overlooked. And that’s a crying shame.

“Some may assume build-ins are more expensive,” says Jared Loveless, operations manager for Vector East builders in Greenport, NY. On the contrary, the cost is usually no more than you’d spend on nice furnishings—and cheaper when your home is still a clean slate. Just be sure to work with your architect early in the design process to roll costs into the initial build.

Think about it: You can’t get a loan for a home that doesn’t exist—which is why you will most likely be getting a construction-to-permanent loan, which covers construction then converts to a regular mortgage once the home building is complete. And here’s the cool thing about these loans that buyers often miss: You can pile everything into it—the water heater, Viking stove, utility bill-slashing solar unit, high-end rain showerhead, everything! So don’t make the mistake, as many do, of buying these additions later with your credit card, which means you’ll be paying it off at 18% interest. Instead, lump them into your mortgage and you’ll pay a mere 4%.

No matter how carefully you plan your home, what’s seemingly set in stone is bound to change: You decide at the last minute you must have the latest Sub-Zero fridge that just hit the market, or you experience a change of heart about the size of your home office. Projects “always go over,” says Loveless. “Because people plan with a budget in mind. But they build with their heart.”

So to keep your construction costs from spiraling out of control, make sure to balance out any cost-adding changes with some budget cutting elsewhere. For example, if you decide you must have a walk-in closet, maybe you can temper or shelve your plans for a wraparound deck until later.

Construction delays are unavoidable, which Loveless attributes to the “domino effect of anything that causes a hiccup.” For example, indecision about the washer/dryer placement postpones the plumber, which in turn delays the electrician and, well, you get the picture. Weather, labor, and material shortages are also commonplace. Yet many buyers still take a contractor’s original completion date as a fait accompli and end up with no place to live. So when you get the initial move-in date from your builder, add a few weeks, or even months—or at least have a contingency plan if things go over.