Kevin and Anne Boyce worked with George Myers of GTM Architects and Stephen Smith of Ventura Group to design to build a custom home in Falls Church. (Ken Wyner)

Nancy Osmond Popovich is director of investments at The Wise Investor Group at Robert W. Baird & Co., a Reston, Va.-based financial-planning and wealth-management firm.

Building a custom home is a dream come true for most, but without proper planning and research, it can quickly become a homeowner’s worst nightmare. With almost infinite options in play, it’s very easy to let the budget spiral out of control.

[Editor’s note: For more on custom homes, see the Real Estate section on Saturday.]

While I’ve helped many clients develop a strategic plan to budget for their dream home, I was able to see firsthand how important it is to be prepared as I recently went through the custom build process myself.

Here are a few key guidelines that can help ensure you don’t end up in over your head:

• Be selective when choosing your builder. Building a custom home can be stressful and expensive, so it’s crucial that you select a team that you trust. Don’t just agree to work with the first charming personality you encounter. Choosing a transparent and honest builder could ultimately save you money. If you can’t have candid conversations from the start about budget, mark-ups or subcontractors, you might want to keep looking for a better fit.

• Define a detailed budget and scope of work. The more detailed the plan and budget, the easier it will be to prevent any unforeseen expenses. How much are your allowances for fixtures? Can you choose where you buy them? What expenses are outside the scope of the contract? These are important points to discuss because they can dramatically change the bottom line for your build.

When you’re building a house from scratch, there will be so many decisions that you had no idea were coming. What type of wood do you want for your floors? Wide planks or standard? What stain? What finish? Peruse interior design websites (Houzz.com is a great one) so that you’re prepared to make an educated decision when the time comes. Remember: Deciding on the fly can cost you.

• Allow for the unexpected. Because construction projects can easily go over budget, it’s common to build in a contingency cushion. With a custom home, I recommend having a 10 to 15 percent contingency for both budget and projected completion date included in the contract.

With that said, don’t be afraid to be assertive and push back when necessary. There may be genuine issues that crop up during the building process that slow things down. But if those issues are costing you money, you don’t just have to listen politely and take it lying down. Advocate for your stake in the process.

• Do your homework. Find friends who’ve been through the process or ask your builder for referrals. Grill them about their experience. Where did they go over budget? What do they regret not spending on? Let their mistakes save you time and money.

• Shop around. Comparison shop for everything to make sure you’re getting the best deal. If the flooring people present you with a quote and say, “Well, that’s just the price of wood these days,” say, “Okay, we’re going to talk to another company to make sure.” Wherever possible, take advantage of your builder’s discount. The builder will always be getting a better rate with suppliers than someone just walking in off the street.

• Stay on top of the job site. When our house was being built, someone stopped by every single day to check in. Know how many people are working and what they are working on at any given time. If you see a subcontractor you’re not familiar with, find out what they will be handling and the cost being saved by outsourcing the piece.

Similarly, stay ahead of the schedule where you can control. Everyone in the home building industry is busy, you are the only person who can keep your project at the top of the pile. Always tell them you need everything before you actually do because getting things done at the last minute will cost you.